CN105937500A

CN105937500A - Centrifugal fan

Info

Publication number: CN105937500A
Application number: CN201610124294.8A
Authority: CN
Inventors: 重田明广; 田积欣公; 黑田辽
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2015-03-05
Filing date: 2016-03-04
Publication date: 2016-09-14
Also published as: JP2016160905A

Abstract

The invention provides a centrifugal fan capable of lowering noise of air circulation caused by stripping of air flows on negative pressure face sides of blades and suppressing increase of power of the fan. The centrifugal fan comprises a main plate (12), a cover (14) arranged opposite to the main plate (12) and a plrualtiy of blades (13) arranged in a radial manner between the main palte (12) and the cover (14), wherein the center of the mainp late is a rotation center, and the blades (13) comprise positive pressure faces (13a) that are front surfaces in a rotating direction and negative pressure faces (13b) that are rear surfaces in the rotating direction; the negative pressure faces (13b) comprise first curved faces (13c) extending from front edges, discontinuous second curved faces (13b) different from the first curved faces (13c), and step increment parts (13e) formed at edges of the first curved faces (13c) and the second curved faces (13d).

Description

Centrifugal fan

Technical field

The present invention be more particularly directed to centrifugal fan excellent in terms of reducing noise.

Background technology

In prior art, in ceiling suspension type and ceiling embedded conditioner, use is centrifuged wind more Fan.

Multiple blades that this centrifugal fan typically by mainboard, configures in the periphery of mainboard radially and be arranged in mainboard Opposition side, cover (shroud) that blade is combined each other constitute, utilize motor to rotate and drive.

In such centrifugal fan, near the joint portion of blade and cover, due to the suction surface generation air-flow at blade Stripping, so there is noise to become big problem.

As the technology of the such problem of solution, the most such as, disclose following technology: blade-shaped become Front edge side has the wing of maximum gauge, and the suction surface formation substantially half wing projection of the peripheral part at blade so that This projection is arranged in compared with the central authorities of projection closer to the position of trailing edge side and from cover at the cross section maximum wing thickness point of projection The direction of lateral lining (hub) side forms (for example, referring to patent documentation 1).

Prior art literature

Patent documentation

Patent documentation 1: No. 4873865 publications of Japanese Patent No.

Summary of the invention

The problem that invention is to be solved

But, in the above prior art, with exit width and the exit width of pressure surface side of the suction surface side of blade Identical situation is compared, and the aperture area of the blowing portion of centrifugal fan narrows, therefore centrifugal in the case of sending identical air quantity The rotating speed of fan accelerates, and fan power increases, the problem that thus there is system performance degradation.

The present invention is the invention completed in view of the above-mentioned problems, its object is to provide the suction surface that can reduce blade Air-supply noise that the stripping of the air-flow of side causes and the centrifugal fan of increase suppressing fan power.

For the method solving problem

In order to achieve the above object, the present invention is a kind of centrifugal fan, it is characterised in that including: mainboard, with above-mentioned mainboard Center be center of rotation；The cover being arranged as opposed to above-mentioned mainboard；And join radially between above-mentioned mainboard and above-mentioned cover The multiple blades put, the most above-mentioned blade include in a rotational direction for front surface pressure surface and in a rotational direction be rear table The suction surface in face, above-mentioned suction surface includes: the 1st curved surface extended from front edge side；In the trailing edge side of above-mentioned suction surface with above-mentioned Discontinuous 2nd curved surface that 1st curved surface is different；With the step difference being formed at above-mentioned 1st curved surface and the border of above-mentioned 2nd curved surface Portion.

According to this structure, when air-flow passes through from step difference, produce negative pressure and be again attached to the suction surface of blade, by This can suppress the stripping of air-flow, and the aperture area of centrifugal fan outlet does not narrow sending of just can reducing that the stripping of air-flow causes Wind noise.

Moreover characterized in that in said structure, above-mentioned step difference is formed multiple at above-mentioned suction surface.

According to this structure, even if reducing at air conditioning load, the rotary speed of fan is slack-off, the slowing of air-flow In the case of, the aperture area of centrifugal fan outlet does not narrows, it is possible to reduce the air-supply noise that the stripping of air-flow causes.

Moreover characterized in that in said structure, above-mentioned step difference is formed from above-mentioned cover side and goes to above-mentioned mainboard side Way in.

According to this structure, even if uprising at air conditioning load, the rotary speed of fan accelerates, the speed of air-flow accelerates In the case of, the aperture area of centrifugal fan outlet does not narrows, it is possible to reduce the air-supply noise that the stripping of air-flow causes.

The effect of invention

In accordance with the invention it is possible to the stripping of suppression air-flow, the aperture area of centrifugal fan outlet does not narrows, it is possible to reduce gas The air-supply noise that the stripping of stream causes, therefore, it is possible to the air-supply providing the stripping of the air-flow of the suction surface side reducing blade to cause is made an uproar Sound and do not make the centrifugal fan that fan power increases.

Accompanying drawing explanation

Fig. 1 is the sectional view of the conditioner of the centrifugal fan of the 1st embodiment representing and being mounted with the present invention.

Fig. 2 is the axonometric chart of the centrifugal fan representing the 1st embodiment.

Fig. 3 is the sectional view of the blade of the centrifugal fan representing the 1st embodiment.

Fig. 4 is the looping pit (orifice) representing the 1st embodiment and the flowing of the air-flow passed through in centrifugal fan Explanatory diagram.

Fig. 5 is the chart representing the centrifugal fan of the present invention with the air quantity of existing centrifugal fan with the relation of noise.

Fig. 6 is the sectional view of the blade of the centrifugal fan of the 2nd embodiment representing the present invention.

Fig. 7 is looping pit and the partial section of centrifugal fan of the 3rd embodiment representing the present invention.

Detailed description of the invention

Hereinafter, referring to the drawings embodiments of the present invention are illustrated.Additionally, the present invention is not limited to this embodiment party Formula.

(the 1st embodiment)

As it is shown in figure 1, conditioner 1 is embedded to be formed at the recess 51 of ceiling 50, utilize bolt 53 and spiral shell Female 54 assembly walls 52 being lifted on the upper surface as recess 51.

Conditioner 1 includes: the housing 2 of the cuboid of a face opening；It is fixed on the electricity of the upper surface 3 of housing 2 Motivation is installed with parts 4；It is installed on the motor 5 of motor installation parts 4；It is installed on rotary shaft centrifugal of motor 5 Fan 6；At the peristome central authorities of housing 2, the suction inlet 7 of the air being made up of grid 7a and filter 7b；It is formed at suction inlet 7 The blow-off outlet 8 of surrounding；For the change pendulum (flap) 9 from the direction of the air-flow of blow-off outlet 8 outflow；In order to will be from suction inlet 7 air sucked guide the looping pit 10 to centrifugal fan 6 in the most horn-like gradually undergauge；Be configured at centrifugal fan 6 The heat exchanger 11 of surrounding.

Fig. 2 is the axonometric chart of the centrifugal fan 6 of the 1st embodiment representing the present invention.

As in figure 2 it is shown, centrifugal fan 6 includes: mainboard 12；The multiple leaves configured radially near the periphery of mainboard 12 Sheet 13；The cover 14 combined each other with the blade of the opposition side by being arranged in mainboard 12.

Mainboard 12 includes: the par 12a of periphery；Central authorities mortar type parts on swell formed the 1st protuberance 12b； With the 2nd protuberance 12c formed in the way of covering the top of the 1st protuberance 12b.

The inner side of the 1st protuberance 12b becomes cavity, is configured with motor 5 in the inner side of the 1st protuberance 12b.At the 1st protuberance 12b Top, be formed with multiple hole 12d in the way of the air-flow needed for the cooling of the motor 5 that flows.Additionally, the 2nd protuberance 12c's Approximate centre is formed with boss (boss) 12e of the rotary shaft of fixed motor 5.

Cover 14 includes cover ora terminalis 14a and cover profile portion 14b；And connect the cover curved surface of cover ora terminalis 14a and cover profile portion 14b 14c.The internal diameter of cover ora terminalis 14a is bigger than the end edge portion of the minimum diameter of looping pit 10, and centrifugal fan 6 is overlapped in cover ora terminalis 14a The mode of looping pit 10 configures.

Then, the shape of blade 13 is illustrated.

Fig. 3 is the sectional view of the blade 13 of the centrifugal fan 6 of the 1st embodiment representing the present invention.

As it is shown on figure 3, blade 13 be included in the direction of rotation of centrifugal fan 6 for front (table) face pressure surface 13a and It is the suction surface 13b in rear (table) face in direction of rotation.Suction surface 13b includes: prolong from the front edge side at the center near centrifugal fan 6 The 1st curved surface 13c stretched；Near the 2nd curved surface 13d of the trailing edge side of the periphery of centrifugal fan 6, it is different songs from the 1st curved surface 13c Face；Step difference 13e with the boundary member being formed at the 1st curved surface 13c and the 2nd curved surface 13d.

Imaginary line 15 is the leaf position of existing centrifugal fan, and it is existing that the 2nd curved surface 13d is formed at ratio with recessed form Centrifugal fan leaf position in the inner part so that the distance between each blade 13 does not narrows.

Additionally, blade 13 is for lightweight, middle vacant lot is constituted.The position of step difference 13e is the wall at suction surface 13b The air-flow stall that flows about and the front being close to of point (pick-up point) peeled off, at the height with step difference 13e H1 is that to represent the Reynolds number of length be that about 6000 (speed of the air-flow of the centrifugal fan 6 of common conditioner 1 is left Right) in the case of, it is preferably from peeling off side in front of the 4h1 to 6h1 lighted.Additionally, height h1 is preferably about 1mm to 2mm.

Then, the effect to the centrifugal fan of present embodiment illustrates.

First, the action to conditioner 1 illustrates.

At Fig. 1, when centrifugal fan 6 rotates to C direction, air-flow W1 is flowed into air regulation from grid 7a and filter 7b Device 1, is rectified at looping pit 10 and guides to centrifugal fan 6.Afterwards, it is blown radially from the periphery of centrifugal fan 6, It is cooled when by heat exchanger 11 or is heated to the temperature specified, being flowed to the direction of regulation by pendulum 9 from blow-off outlet 8 Go out.

The obstructed over-heat-exchanger of a part 11 of air-flow W1, and become capture motor 5 heat cooling air-flow W2 and from Periphery short circuit (short circuit) of looping pit 10, again flow into the circulating current W3 of centrifugal fan 6, in centrifugal fan 6 Collaborate with air-flow W1.

Then, the flowing to the air-flow W1 passed through in centrifugal fan 6 illustrates.

Fig. 4 is the explanatory diagram of the flowing representing the air-flow W1 passed through in looping pit 10 and centrifugal fan 6.

As shown in Figure 4, air-flow W1 has the air-flow W1a near cover 14, by cover 14 and the gas of the substantial middle of mainboard 12 Stream W1b and the air-flow W1c near mainboard 12, the speed of air-flow is W1a ＜ W1b ＜ W1c.

Additionally, as it is shown on figure 3, at suction surface 13b, because centrifugal fan 6 rotates to B direction, so air-flow W1 to leave, Therefore, it is susceptible to peel off compared with the air-flow W1 flowed at pressure surface 13a.Particularly in the trailing edge side of suction surface 13b, easily The stall of the near wall producing the Development of Boundary Layer of air-flow W1 and cause.

In the present embodiment, by the trailing edge side setting table order difference part 13e at suction surface 13b, it is possible to air-flow W1's Peel off before Development of Boundary Layer, and produce negative pressure by producing circulation eddy current near step difference 13e, guide air-flow W1, makes the air-flow W1 peeled off at step difference 13e be again attached to the 2nd curved surface 13d.

Being therefore prevented from the development of the boundary region of the air-flow W1 of suction surface 13b, suppression is peeled off.Thus, centrifugal fan exports Aperture area does not narrows, it is possible to reduce the air-supply noise that the stripping of air-flow causes.

Fig. 5 be the centrifugal fan being provided with step difference that represents and make the present invention with existing be not provided with step difference from The chart of the relation of air quantity and noise in the case of the action respectively of heart-wind syndrome fan.

As it is shown in figure 5, in the case of with identical air quantity action, the centrifugal fan of the present invention and existing centrifugal fan phase Ratio can make noise reduce.

As it has been described above, in the present embodiment, because being provided with step difference 13e in the trailing edge side of suction surface 13b, so It is prevented from the development of the boundary region of air-flow W1 at suction surface 13b, it is possible to suppression is peeled off.Therefore, the outlet of centrifugal fan 6 Aperture area does not narrows, it is possible to reduce the air-supply noise that the stripping of air-flow causes.

As a result of which it is, the air-supply noise that the stripping of the air-flow of the suction surface 13b side reducing blade 13 causes can be provided also And do not make the centrifugal fan 6 that fan power increases.

It addition, in the present embodiment, the height h1 making step difference 13e is certain, but can also be according to air-flow W1 Rapid change height h1 (such as, speed the most just order height h1 the lowest).By using such structure, it is possible to more suppress Peel off, using the teaching of the invention it is possible to provide air-supply noise that the stripping of air-flow of the suction surface 13b side reducing blade 13 causes and do not make fan move The centrifugal fan 6 that power increases.

Additionally, in the present embodiment, the position of the step difference 13e of the order trailing edge away from suction surface 13b is certain, no Crossing can also be according to the rapid change position (such as, speed is the most more gone toward trailing edge side) of air-flow W1.Such by using Structure, it is possible to suppress further to peel off, using the teaching of the invention it is possible to provide the air-supply that the stripping of the air-flow reducing the suction surface 13b side of blade 13 causes Noise and do not make the centrifugal fan 6 that fan power increases.

(the 2nd embodiment)

Then the 2nd embodiment of the present invention is illustrated.

Fig. 6 is the sectional view of the blade 13 of the centrifugal fan 6 of the 2nd embodiment representing the present invention.It addition, to above-mentioned Part or suitable part that 1st embodiment is identical mark identical reference, and the description thereof will be omitted.

As shown in Figure 6, suction surface 13b includes: the 1st curved surface 13c；2nd curved surface 13d；It is formed at the 1st curved surface 13c and the 2nd bent 1st step difference 13g of the boundary member of face 13d；3rd curved surface 13f, they are different from the 1st curved surface 13c and the 2nd curved surface 13d Curved surface, is located close to the trailing edge side of the periphery of centrifugal fan 6 compared with the 2nd curved surface 13c；Be formed at the 2nd curved surface 13d and the 3rd 2nd step difference 13h of the boundary member of curved surface 13f.

The position of the 1st step difference 13g and the 2nd step difference 13h is that the air-flow flowed about at the wall of suction surface 13b loses Speed and the front being close to of point (pick-up point) peeled off, with the 1st step difference 13g and the height of the 2nd step difference 13h Degree h2, h3 are that to represent the Reynolds number of length be about the 6000 (speed of the air-flow of the centrifugal fan 6 of common conditioner 1 About degree) in the case of, it is preferably from peeling off side in front of the 4h2 to 6h2 and 4h3 to 6h3 lighted.Additionally, height h2 and h3 is equal It is preferably about 1mm to 2mm, highly h2 and h3 and is not necessarily identical height.

Then, the effect to present embodiment illustrates.

In the present embodiment, as it is shown in figure 5, at suction surface 13b, because centrifugal fan 6 rotates to B direction, so gas Stream W1 to leave, and therefore, is susceptible to peel off compared with the air-flow W1 flowed at pressure surface 13a.Particularly suction surface 13b's Trailing edge side, easily causes the Development of Boundary Layer of air-flow W1 and the stall of near wall that causes.Further, at centrifugal fan 6 Rotate speed slow, air-flow slow in the case of, easily produce the pick-up point of air-flow at front edge side.

Therefore, the 2nd step difference 13h is set by the trailing edge side at suction surface 13b, again exists in the boundary region of air-flow W1 Peel off before 2nd curved surface 13d development, and produce negative pressure by producing circulation eddy current near the 2nd step difference 13h, Guide air-flow W1, make the air-flow W1 peeled off at the 2nd step difference 13h be again attached to the 3rd curved surface 13f.

As it has been described above, in the present embodiment, by arranging the 1st step difference 13g and in the trailing edge side of suction surface 13b 2 step difference 13h, even if also being able to prevent in negative pressure in the case of speed slow in rotating of centrifugal fan 6, air-flow is slow The development of the boundary region of the air-flow W1 of face 13b, it is possible to suppression is peeled off.Therefore, even if in air conditioning load reduction, the rotation of fan Rotary speed is slack-off and the transporting velocity of air-flow slow in the case of, the aperture area of the outlet of centrifugal fan 6 does not narrows, it is possible to fall The air-supply noise that the stripping of low-flow causes.

Even if as a result of which it is, can provide reduce at air conditioning load, the rotary speed of fan is slack-off and air-flow defeated Send slow-footed in the case of also reduce blade 13 the air-supply noise that causes of the stripping of air-flow of suction surface 13b side and do not make wind Agitate the centrifugal fan 6 that power increases.

Additionally, in the present embodiment, the 1st step difference 13g and the secondary structure of the 2nd step difference 13h are used, at gas The speed of stream is slower, in the case of trailing edge exists the stripping of air-flow of suction surface 13b, it is possible to by increasing step further Difference portion and become multilevel hierarchy and suppress further to peel off, using the teaching of the invention it is possible to provide reduce the stripping of air-flow of the suction surface 13b side of blade 13 From the air-supply noise caused and the centrifugal fan 6 not making fan power increase.

(the 3rd embodiment)

Then the 3rd embodiment of the present invention is illustrated.

Fig. 7 is the partial section of the centrifugal fan 6 of the 3rd embodiment representing the present invention.It addition, to the above-mentioned 1st Embodiment and the identical part of the 2nd embodiment or the identical reference of suitable part mark, the description thereof will be omitted.

As it is shown in fig. 7, step difference 13e is arranged to going to mainboard 12 side from cover 14 side in the short transverse of blade Middle part.

In the present embodiment, also as the respective embodiments described above, at Fig. 7, at suction surface 13b, owing to air-flow W1 wants Leave, be easily peeling compared with the air-flow W1 flowed at pressure surface 13a.

Particularly in the trailing edge side of suction surface 13b, easily produce the Development of Boundary Layer of air-flow W1 and the near wall that causes Stall.Further, at cover curved surface 14c, the change of airflow direction is big, is easily peeling.On the contrary, mainboard 12 side is from air-flow stream The cover ora terminalis 14a side entered is risen and be there is bigger distance, the inclination also ratio cover side gone to par 12a from the 1st protuberance 12b The curved surface of 14c eases up, and is therefore not likely to produce the stripping of air-flow.Further, slow, the speed ratio of air-flow is rotated at centrifugal fan 6 In the case of relatively slow, the pick-up point of air-flow easily produces in trailing edge side, and is not easy to be peeling.

In the present embodiment, by step difference 13e is arranged to the middle part gone from lateral mainboard 12 side of cover 14, lean on The air-flow W1a of the cover 14 of the nearly stripping easily producing air-flow peeled off before suction surface 13b development boundary region, and by platform Produce circulation eddy current near order difference part 13e and produce negative pressure.Thus, so that step difference 13e peel off the W1a that stands up the most attached The mode in the 2nd curved surface 13d of guides air-flow W1a, and is not likely to produce stripping near the air-flow W1c of the slow mainboard 12 of air-flow From, upset air-flow in turn thus without the stripping due to step difference 13e.

As a result of which it is, even if rotary speed high at air conditioning load, fan is fast and air-flow fireballing in the case of, The aperture area of centrifugal fan outlet does not narrows, it is possible to reduce the air-supply noise that the stripping of air-flow causes further.

As it has been described above, in the present embodiment, because step difference 13e is arranged to the way gone from lateral mainboard 12 side of cover 14 In, even if so the speed of, air-flow fast rotating of centrifugal fan 6 is than in the case of very fast, it is also possible to prevent suction surface 13b's The development of the boundary region of air-flow W1, suppression is peeled off.Thus, the gas even if the rotary speed of, fan low at air conditioning load is slow Stream slow-footed in the case of, the aperture area of centrifugal fan 6 outlet does not narrows, it is possible to the stripping reducing further air-flow is drawn The air-supply noise risen.

Even if as a result of which it is, can provide that rotary speed high at air conditioning load, fan is fast and the speed of air-flow is fast In the case of also be able to reduce air-supply noise that the stripping of air-flow of the suction surface 13b side of blade 13 causes and do not make fan move The centrifugal fan 6 that power increases.

Probability is utilized in industry

As it has been described above, the air-supply that the stripping of the centrifugal fan of the present invention air-flow that can reduce the suction surface side of blade causes Noise and do not make fan power increase, therefore, it is possible to be applied to ceiling formula and ceiling embedded air conditioner And the purposes such as various air interchangers.

Description of reference numerals

12 mainboards

13 blades

13a pressure surface

13b suction surface

13c the 1st curved surface

13d the 2nd curved surface

13e step difference

13f the 3rd curved surface

13g the 1st step difference

13h the 2nd step difference

14 covers

Claims

1. a centrifugal fan, it is characterised in that including:

Mainboard, with the center of described mainboard as center of rotation；

The cover being arranged as opposed to described mainboard；With

The multiple blades configured radially between described mainboard and described cover, wherein

Described blade include in a rotational direction for front surface pressure surface and in a rotational direction be rear surface suction surface,

Described suction surface includes:

The 1st curved surface extended from front edge side；

Discontinuous 2nd curved surface different from described 1st curved surface in the trailing edge side of described suction surface；With

It is formed at the step difference of described 1st curved surface and the border of described 2nd curved surface.

2. centrifugal fan as claimed in claim 1, it is characterised in that:

Described step difference is formed multiple at described suction surface.

3. centrifugal fan as claimed in claim 1 or 2, it is characterised in that:

Described step difference is formed to the way gone to described mainboard side from described cover side.