JP3008930B2 - Impeller for blower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an impeller for a blower having a so-called airfoil blade.

[0002]

2. Description of the Related Art Various types of blades of an impeller used for a blower have been proposed. One of them is to enhance the aerodynamic performance of the blade by suppressing air flow separation on the blade surface. From the viewpoint of such, a so-called "airfoil blade" having a shape in which the blade thickness of the leading edge of the blade is increased and the blade thickness is continuously gradually reduced from the leading edge to the trailing edge is known. I have.

[0003]

However, in such an airfoil blade, the responsiveness to a change in the inflow angle of the airflow is impaired unless the blade thickness at the leading edge of the airflow inlet blade is considerably increased. Therefore, separation of the airflow is likely to occur on the negative pressure side of the leading edge of the blade, which causes problems such as generation of aerodynamic noise and deterioration of aerodynamic performance.

If the thickness of the leading edge of the blade is increased to address such a problem, the resistance of the airflow flowing into the leading edge of the blade is increased by the increase in the thickness of the blade, and the blowing efficiency is reduced. A new problem.

Accordingly, the present invention suppresses the separation of airflow on the leading edge side of the suction surface of the blade and the development of the boundary layer on the trailing edge side without increasing the blade thickness of the leading edge. An object of the present invention is to provide an impeller for a blower which realizes both suppression and a synergistic effect thereof, thereby enabling both reduction of aerodynamic noise and improvement of aerodynamic performance.

[0006]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

In the first aspect of the present invention, the blade thickness is reduced to the leading edge 2a.
To the trailing edge 2b, and the hollow wings 2, 2,.
In the impeller for a blower provided with the negative pressure surface 2
A plurality of small holes 4, 4,... Communicating the surface of the suction surface 2B and the vacant space portion 23 are formed in the vicinity of the front edge portion 2a in B, and the rear edge portion 2b of the suction surface 2B is formed.
Is characterized in that a long hole 5 extending in the circumferential direction and communicating the surface of the negative pressure surface 2B with the empty space portion 23 is formed in the vicinity of.

According to a second aspect of the present invention, in the impeller for a blower according to the first aspect, the diameter of the small hole 4 is increased from the surface side of the negative pressure surface 2B toward the cavity 23. It is characterized in that it has a shape that does.

In the third invention of the present application, the first or the second
The blower impeller according to the invention is characterized in that the opening area of the elongated hole 5 is larger than the sum of the opening areas of the plurality of small holes 4, 4,... On the blade surface side.

According to a fourth aspect of the present invention, in the impeller for a blower according to the first, second or third aspect, the blade 2 is provided with a concave portion 24 on the surface of the blade 2 on the side of the negative pressure surface 2B. The wing body 21 has a lid-like form that fits into the recess 24 so as to cover the recess 24 of the wing body 21 so as to form the empty space 23 therebetween. Edge 2a
Are provided in a portion corresponding to the vicinity of the plurality of small holes 4, 4,.
And a slot 5 corresponding to the vicinity of the trailing edge 2b.
And a lid 22 provided with each of them is united and joined.

A fifth invention of the present application is the blower impeller according to the fourth invention, characterized in that the wing body 21 is formed integrally with the hub 3.

[0012]

According to the present invention, the following effects can be obtained by adopting such a configuration.

According to the impeller for a blower according to the first invention of the present application, the vicinity of the leading edge 2a in the suction surface 2B of the hollow blades 2, 2,... A plurality of small holes 4, 4,... Communicating the surface of the suction surface 2B and the vacant space portion 23 are formed in the suction surface 2B and near the rear edge 2b near the outer peripheral edge 2c in the suction surface 2B. Has a long hole 5 which communicates the surface of the negative pressure surface 2B with the vacant space portion 23 and extends in the circumferential direction. Therefore, when the impeller rotates, the blade tip vortex 10 generated with the rotation is formed. (That is, the blade 2 wraps around the outer peripheral edge 2c from the pressure surface 2A side to the negative pressure surface 2B side and extends along the negative pressure surface 2B.
Eddy current flowing to c side. 4) flows through the elongated hole 5 to act as an ejector on the elongated hole 5 to allow the air in the vacant space 23 to pass through the elongated hole 5 to the suction surface 2B.
A suction force in the direction of suction is generated on the surface side of the surface. The suction action generated in the elongated hole 5 is transmitted to the small holes 4, 4,... Provided on the front edge portion 2a side through the empty space portion 23, and the front edge portion 2a A part of the air flowing into the portion is sucked into the vacant space portion 23 from the small holes 4, 4,... And further flows out to the rear edge portion 2b through the long hole 5.

As a result, on the side of the leading edge 2a of the suction surface 2B of the blade 2, the small holes 4, 4,... With the suction effect, the separation of the airflow on the surface of the front edge 2a is suppressed as much as possible. Meanwhile,
On the rear edge 2b side of the negative pressure surface 2B near the outer peripheral edge 2c, the negative pressure surface 2 passes through the slot 5 from the vacant space 23 side.
The airflow flowing to the surface side of B causes turbulence in the airflow on the surface of the trailing edge portion 2b, and the development of the wing surface boundary layer on the surface is suppressed as much as possible. The synergistic effect of these two makes it possible to provide an impeller for a blower that has low aerodynamic noise and excellent aerodynamic performance.

According to the impeller for a blower according to the second invention of the present application, in the impeller for the blower according to the first invention, the small hole 4 is formed by the vacant portion from the surface side of the negative pressure surface 2B. Since the hole diameter is increased toward 23, the suction force from the vacant space 23 side effectively acts on the small hole 4 portion, and the air flow is smoothly sucked through the small hole 4. The effect of suppressing the separation of the airflow at the front edge portion 2a of the suction surface 2B is further enhanced, and the suction surface of the small holes 4 is smaller than when, for example, the small holes 4 are straight holes having the same diameter. Since the opening area on the surface of 2B is small, the influence of the formation of the small holes 4 on the aerodynamic noise is reduced as much as possible, whereby the effects described above are further enhanced.

According to the impeller for a blower according to the third invention of the present application, the opening area of the long hole 5 is determined by the sum of the opening areas of the plurality of small holes 4 on the blade surface side. , A smooth flow of the air flow sucked into the vacant space portion 23 from the small holes 4, 4,... And flowing out from the long hole 5 is realized, and the effect described above is further enhanced. Will be enhanced.

According to the impeller for a blower according to the fourth invention of the present application, the wing 2 is provided with a wing body 21 having a concave portion 24 on a surface of the wing 2 on the side of the negative pressure surface 2B, It has a lid-like form that fits into the concave portion 24 so as to cover the concave portion 24 and can form the vacant space 23 therebetween, and has A plurality of small holes 4, 4,... And a lid 22 provided with the long hole 5 at a position corresponding to the vicinity of the rear edge 2b.
It is configured by uniting and joining.

Therefore, for example, when the blade 2 is integrally formed by blow molding or the like, the small hole 4 is formed in a shape in which the hole diameter increases from the surface side of the negative pressure surface 2B toward the empty space portion 23. However, by forming the wing 2 as a separate structure of the wing body 21 and the lid 22 as described above, it becomes possible to set the shape of the small hole 4 as described above. The effect will be more reliably realized.

When the wings 2 are integrally formed by blow molding or the like, the shape of the vacant space 23 provided inside the wing 2 and, consequently, a portion corresponding to the vacant space 23 It is difficult to keep the thickness of the wings as designed,
Is formed as a separate structure of the wing main body 21 and the lid 22 as described above, and these are formed by molding, respectively, thereby designing the shape of the above-mentioned empty space portion 23 and the thickness of the portion corresponding to the empty space portion 23. It is easy to do as it is, and that is the wing 2 as a product
Reliability is improved.

According to the impeller for a blower according to the fifth invention of the present application, since the wing body 21 is formed integrally with the hub 3, for example, the wing 2 and the hub 3 have a separate structure,
Compared to the case of assembling this after the fact and obtaining an impeller,
The manufacture of the impeller is easy, and cost reduction can be expected accordingly.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an impeller for a blower according to the present invention will be specifically described based on a preferred embodiment.

FIG. 1 shows an external appearance of a resin impeller 1 used for a blower, and FIG. 2 shows a plan view of a blade 2 provided on the impeller 1, respectively. Reference numeral 1 denotes a configuration in which a plurality of blades 2 (three in this embodiment) are arranged on an outer peripheral surface of a hub 3 at predetermined intervals in a circumferential direction thereof. In particular, in this embodiment, the wing 2 has a combined structure of a wing body 21 and a lid 22 described below, and the wing body 21 is formed integrally with the hub 3. Thus, the impeller 1 is formed as an integral structure.

That is, as shown in FIGS. 2 and 3, the wing 2 has a relatively large thickness at the leading edge 2a and a gradually decreasing thickness from the leading edge 2a to the trailing edge 2b. A hollow airfoil wing having a cross-sectional shape and a forward wing shape in which a leading edge portion 2a protrudes forward in the rotational direction, and is attached to the outer peripheral surface of the hub 3 with a required wing angle. Of the two side surfaces, the side surface facing forward in the rotation direction is the pressure surface 2A, and the opposite side surface is the negative pressure surface 2B. The wing 2 is connected to a wing body 21 described below.
And a lid 22.

The wing body 21 has one side surface 21a.
Is the pressure surface 2A and the other side surface 21b
A substantially fan-shaped concave portion 24 is provided at a position near the leading edge of the blade (the side surface on the side of the negative pressure surface 2B). The wing body 21 is integrally formed with the hub 3 by molding with a resin material in a state where the wing base end 2d is joined to the outer peripheral surface of the hub 3 at a predetermined wing angle. The wing body 2
Of course, 1 is provided in the same number as the blades 2, 2,... Provided in the impeller 1.

The lid body 22 is a lid-like body having a predetermined thickness and a flat shape conforming to the outer edge shape of the recess 24 of the wing body 21, and is formed of a resin material in the same manner as the wing body 21. The one side surface 22a forms a part of the negative pressure surface 2B of the blade 2 described above. In addition, the lid 22 has a plurality of small holes 4, 4,.
And a single elongated hole 5, respectively.

The small hole 4 has such a shape that the diameter of the hole gradually increases from one side surface 22a of the lid 22 to the other side surface 22b, and the lid 22 has such a shape. A plurality of small holes 4, 4,... Are scattered at locations corresponding to the vicinity of the leading edge 2a of the wing 2 and over substantially the entire area in the radial direction. On the other hand, the slot 5
The outer periphery of the lid 22 near the rear edge, that is, the wing 2
The wing 2 is formed to extend in the circumferential direction of the blade 2 at a position corresponding to a portion near the outer peripheral edge 2c of the trailing edge 2b. Between the small holes 4, 4,... And the long hole 5, the sum of the opening areas of the small holes 4, 4,. 5 is set to be smaller than the opening area on the surface of the negative pressure surface 2B.

By fitting the lid 22 into the recess 24 of the wing body 21 formed as described above so as to cover the recess 24 from above, the two are joined, and these are joined together, as shown in FIG. As shown in FIG. 5, the blade 2 having an airfoil blade shape having a cavity 23 formed therein with the recess 24 is obtained. In the wing 2 configured by combining the wing body 21 and the lid 22 in this way, the small pressure surface previously provided on the lid 22 in the vicinity of the front edge 2a on the suction surface 2B. Hole 4,4, ...
However, the elongated holes 5 previously provided in the lid 22 are arranged in the vicinity of the trailing edge 2b on the negative pressure surface 2B.

In the impeller 1 having the above configuration, the following operation and effect can be obtained.

That is, when the impeller rotates, the outer peripheral edge 2c of the blade 2 is rotated from the pressure surface 2A side to the suction surface as shown in FIGS. 1, 2 and 4 with the rotation. 2B
The tip vortex 10 is formed around the suction side 2B and flows toward the outer peripheral edge 2c along the suction surface 2B.
It develops gradually from the leading edge 2a to the trailing edge 2b of the wing 2 (see FIGS. 1 and 2). Therefore, the slot 5 is located at a position where the tip vortex 10 is most developed, and the ejector effect due to the flow of the tip vortex 10 acts on the slot 5, thereby causing the slot 5 to flow. The suction action in the direction of sucking the air in the vacant space portion 23 to the surface side of the negative pressure surface 2B occurs. The suction effect generated in the elongated hole 5 is transmitted to the small holes 4, 4,... Provided on the front edge portion 2a side through the empty space portion 23, and the front edge portion 2a A suction action is performed on the air flowing into the portion through the small holes 4, 4,. As a result, a part of the airflow flowing into the front edge portion 2a is sucked into the empty space portion 23 through the small holes 4, 4,. ,
Further, after flowing toward the long hole 5 side in the vacant space portion 23, it flows out again from the long hole 5 to the surface of the negative pressure surface 2B on the trailing edge portion 2b side, and becomes a downstream flow.

As described above, as a result of the generation of the airflow flowing from the leading edge 2a to the trailing edge 2b on the suction surface 2B through the vacant space 23, the suction surface 2
On the front edge 2a side of B, the suction action into the vacant space 23 at the small holes 4, 4,... Acts on the air flow, so that the air on the surface of the front edge 2a Flow separation is suppressed as much as possible. On the other hand, the trailing edge 2 of the negative pressure surface 2B
On the b side, the air flow from the vacant space portion 23 side to the surface side of the negative pressure surface 2B through the long hole 5 causes turbulence in the air flow on the surface of the trailing edge portion 2b. The development of the wing surface boundary layer at the site is suppressed as much as possible. Due to the synergistic effect of these two, the impeller 1 has characteristics of low aerodynamic noise and excellent aerodynamic performance.

In this case, the small hole 4 provided in the vicinity of the leading edge 2a of the blade 2 has a shape in which the hole diameter increases from the surface side of the negative pressure surface 2B toward the empty space 23. Therefore, the vacant space portion 23 is
The suction force from the side will work effectively. As a result, the air flow is smoothly sucked through the small holes 4,
The effect of suppressing the separation of the airflow at the front edge portion 2a of the negative pressure surface 2B is further enhanced.
Since the opening area of the small holes 4 on the surface of the negative pressure surface 2B is smaller than when the
The effect on the aerodynamic noise due to the formation of the air-fuel ratio is reduced as much as possible.

Further, the air flow sucked into the vacant space portion 23 and flowing from the small holes 4, 4,... To the long hole 5 side receives centrifugal force due to the rotation of the blade 2 and moves toward the outer periphery. In this case, since the elongated hole 5 is provided at the rear edge 2b of the negative pressure surface 2B near the outer peripheral edge 2c, the position of the air flow in the vacant space 23 and its position The formation position of the slot 5 serving as an outlet substantially matches the position of the slot 5, so that the air flow from the slot 5 is blown out more smoothly, which further reduces aerodynamic noise and improves aerodynamic performance.

Since the opening area of the long hole 5 is larger than the sum of the opening areas of the plurality of small holes 4, 4,... On the blade surface side, the small holes 4, 4,. ················ Smooth flow of the air flow sucked into the vacant space portion 23 and flowing out of the long hole 5 is realized, and reduction of aerodynamic noise and further improvement of aerodynamic performance can be expected.

On the other hand, in this embodiment, the wing 2 is combined with the wing body 21 and the small holes 4, 4,... And the long hole 5 are formed in advance. Since it is composed of the lid 22, the small hole 4
Can easily be formed even when the hole diameter increases from the surface side of the negative pressure surface 2B toward the vacant space 23, and the shape of the vacant space 23 and the vacant space It is also easy to manufacture the thickness corresponding to the portion 23 as designed.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of an impeller for a blower according to the present invention.

FIG. 2 is a plan view of a blade in the impeller shown in FIG.

FIG. 3 is an enlarged sectional view taken along the line III-III of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG. 2;

[Explanation of symbols]

1 is an impeller, 2 is a blade, 2A is a pressure surface, 2B is a suction surface, 2
a is a leading edge, 2b is a trailing edge, 2c is an outer peripheral edge, 3 is a hub, 4 is a small hole, 5 is a long hole, 10 is a wing tip vortex, 21 is a wing body, 22 is a lid, 23 is The vacant space 24 is a concave portion.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F04D 29/18-29/38 F04D 29/66

Claims (5)

(57) [Claims] The wing thickness is increased from the leading edge (2a) to the trailing edge (2).
b) Hollow wings (2), (2),.
The impeller for a blower comprising: a leading edge (2a) on the suction surface (2B) of the blade (2).
Near the surface of the suction surface (2B) and the vacant space (23).
Are formed, and a plurality of small holes (4), (4),... Are formed, and an outer peripheral edge of the negative pressure surface (2B) is formed.
(2c) Near the rear edge (2b) near the suction surface (2c).
An impeller for a blower, characterized in that an elongated hole (5) extending in the circumferential direction is formed so as to communicate the surface of (B) with the empty space (23). 2. The small hole (4) according to claim 1, wherein a diameter of the small hole (4) increases from a surface side of the negative pressure surface (2B) toward the empty space portion (23). Impeller for blowers. 3. The method of claim 1 or 2, the opening area of the slot (5), the plurality of small holes (4), (4), than the sum of the opening area of the blade surface side of ... An enlarged impeller for a blower. 4. A wing body (21) according to claim 1, 2 or 3, wherein said wing (2) is provided with a concave portion (24) on a surface of the wing (2) on the side of the suction surface (2B). The wing has a lid-like form capable of fitting into the concave portion (24) so as to cover the concave portion (24) of the wing body (21) and forming the empty space portion (23) therewith. The above-mentioned plurality of small holes (4), (4),... Are provided in a portion corresponding to the vicinity of the front edge (2a) of (2).
Further, an impeller for a blower, wherein a lid body (22) provided with the elongated hole (5) at a position corresponding to the vicinity of the rear edge part (2b) is united and joined. 5. An impeller for a blower according to claim 4, wherein said wing body (21) is formed integrally with said hub (3).