JP3109466B2 - 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 an impeller for a blower used for an outdoor unit for an air conditioner, and more particularly to an impeller for a blower having a wing having a hollow portion therein.

[0002]

2. Description of the Related Art With respect to the blades of an impeller for a blower, a technique of forming an airfoil cross section (thick blade shape) in order to improve the blowing performance is widely known. When the airfoil shape is adopted, the separation of the airflow is suppressed irrespective of the fluctuation of the inflow angle of the air, so that the air blowing performance is improved as compared with the thin blade.

[0003] As a countermeasure for reducing the drawback of the airfoil-shaped wing, in which the weight of the wing is increased as compared with the thin wing-shaped wing, it is known that the wing has a hollow structure.

[0004]

The use of a hollow-structured blade can reduce the weight of an impeller for a blower, but the range of the hollow portion is too wide, or the plate of the shell portion that forms the hollow portion. If the thickness is made too thin, the strength of the wing may be reduced, and the wing may be damaged during rotation. In particular, when adopted in an outdoor unit for an air conditioner, if the wing is damaged, fragments of the damaged wing will stick into an expensive heat exchanger and damage the heat exchanger.

[0005] On the other hand, the hollow area is made too narrow,
When the thickness of the shell portion is increased, the effect of reducing the weight of the impeller for the blower is diminished, and the merit of the solid structure blade is diminished.

SUMMARY OF THE INVENTION An object of the present invention is to provide an impeller for a blower in which the advantages of weight reduction over those having solid-structured wings are maintained to some extent, and the strength of the wings is easily ensured.

[0007]

According to a first aspect of the present invention, there is provided an impeller for a blower including a hub and blades. The wing has a hollow portion inside. The relational expression between the warp line length Lm of the blade in the cross-sectional shape at the average diameter of the flow passage area and the thickness t1 of the blade at the position of the front end in the rotation direction of the hollow portion is as follows: 0.02 ≦ (t1 / Lm) ≦ 0.10 It is. Further, the relational expression between the warp line length Lm in the cross-sectional shape at the average diameter of the flow path area and the blade thickness t2 at the position of the rear end of the hollow portion in the rotation direction is 0.01 ≦ (t2 / Lm) ≦ 0. 08. The average diameter of the flow passage area (D) is expressed as D = ((Do ² + Dh ² ) / 2) ^0.5 where Do is the outer diameter of the impeller for the blower and Dh is the outer diameter of the hub. Things. In general, the cross-sectional shape at the flow path area average diameter (D) is used as a reference for the cross-sectional shape of the blade.

Here, the thickness of the blade at the position where the hollow portion of the blade starts when viewed from the front side in the rotational direction and the thickness of the blade at the position where the hollow portion of the blade ends end are secured by a predetermined thickness.
The strength of the wing is obtained even in a part where the strength tends to be insufficient due to the existence of the hollow part.

In addition, the thickness of the blade at the position where the hollow portion of the blade starts when viewed from the front side in the rotational direction and the thickness of the blade at the position where the hollow portion of the blade ends end are secured by a predetermined thickness, so that the thickness of the blade is reduced. The hollow part is formed to a part thinner part to reduce the weight of the blade, and the weight of the impeller for the blower is reduced, and the strength of the blade is obtained even in the part where the strength tends to be insufficient due to the presence of the hollow part. . In addition, since the weight reduction of a blade also leads to the saving of the raw material of a blade, it also reduces the manufacturing cost of the impeller for a blower.

As a result, the impeller for a blower according to the present invention retains the merit of reducing the weight to a certain extent with a blade having a solid structure, and secures the strength of the blade.

The present invention is applied to an impeller for a blower having metal wings and to an impeller for a blower having resin wings. A blower impeller according to a second aspect includes a hub and a plurality of blades. The inner peripheral end of the wing is attached to a hub, and a hollow portion is formed inside the wing. The ratio (t / L) of the blade thickness t at the position of the front end in the rotation direction of the hollow portion to the warp line length L of the blade is:
It becomes larger as it approaches the inner peripheral end.

The load applied to the blades of the impeller for a blower is mainly a centrifugal force, and the distribution of the load applied to each part of the blades increases as it approaches the mounting portion with the hub, that is, as it approaches the inner peripheral end. In general, for the purpose of improving performance, a wing having a shape in which the leading edge of the wing is located forward in the rotation direction toward the outer peripheral side,
A so-called forward wing may be used. In the forward wing, a high tensile force or the like is applied by a centrifugal force or the like, especially in the vicinity of the portion where the hub is mounted, especially in the rotational direction of the blade.

Here, the ratio of the thickness t of the blade at the position of the front end in the rotation direction of the hollow portion to the length L of the warp line of the blade is increased as approaching the inner peripheral end. The stress in the vicinity of the mounting portion with the hub at the front in the rotation direction is suppressed. Thereby, breakage of the blade during rotation of the impeller for the blower is suppressed. On the other hand, in a portion where only a relatively small load is applied, the hollow portion is formed to a range where the thickness of the blade is small, and the weight of the blade is reduced.

According to a third aspect of the present invention, an impeller for a blower includes a hub and a plurality of blades. The inner peripheral end of the wing is attached to a hub, and a hollow portion is formed inside the wing. During ~
The distance between the front end of the hollow portion and the front end of the wing increases as the distance between the wing and the hub becomes closer.

Here, the distance between the front end of the hollow portion and the front end of the wing is
By increasing the separation closer to the mounting portion of the wing and the hub, it is possible to secure a certain cross-sectional area of a portion in the rotation direction ahead of the hollow portion of the wing near the mounting portion of the wing and the hub. Thereby, breakage of the blade during rotation of the impeller for the blower is suppressed.

According to a fourth aspect of the present invention, there is provided an impeller for a blower according to any one of the first to third aspects, wherein the wing is formed by joining a wing body and a lid. The space surrounded by the wing body and the lid becomes a hollow portion of the wing.

In this case, since the wing having a hollow structure has a two-body structure of a wing body and a lid, the shape of the hollow portion (position of the front end in the rotation direction and the rear end in the rotation direction) is smaller than that of the air-assist type wing. Is easy to form accurately. Therefore, it is possible to appropriately reduce the weight of the wing while ensuring the strength corresponding to the force applied to each part of the wing.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 shows a propeller fan (an impeller for a blower) according to an embodiment of the present invention. The propeller fan 1 is used to blow air in an outdoor unit 10 for an air conditioner as shown in FIGS. 2 and 3.

As shown in FIG. 2, the outdoor unit 10 comprises a heat exchange room 8 and a machine room 9, both of which are separated by a partition plate. The heat exchange room 8 contains the propeller fan 1
Are mounted on a rotating shaft 4a, and a heat exchanger 5 having an L-shaped cross section, and a bar-shaped blowing grill 6 is fitted on the front surface. When the propeller fan 1 is rotated by the motor 4, air passing through the heat exchanger 5 is blown out from the grill 6 along the direction of an arrow indicated by a two-dot chain line in FIG.
Flows to The propeller fan 1 rotates in the direction of the arrow shown in FIG. The machine room 9 includes a compressor unit 7
And electrical components (not shown) are provided.

As shown in FIGS. 1, 3, and 4, the propeller fan 1 is joined to a cylindrical hub 2 at an outer peripheral surface of the hub 2 with a predetermined inclination angle in a blowing direction. And an outer diameter (Do) of 4
50 mm. A groove or the like (not shown) is formed in the inner peripheral portion of the hub 2 so as to be non-rotatably fitted with the rotating shaft 4 a of the motor 4. Although the propeller fan 1 having three blades is employed here, a fan having four or five blades may be used. The dimension R in FIG. 4 is generally a diameter dimension for determining the standard of the cross-sectional shape of the blade, and is called a channel area average radius. A value twice as large as this flow area average radius (R) is the flow area average diameter (D). This flow path area average diameter D is expressed by the following equation.

D = ((Do ² + Dh ² ) / 2) ^0.5 where Do: outer diameter of propeller fan 1 Dh: outer diameter of hub 2 Therefore, the average radius (R) of the flow path area is R = D / 2 = ((Do ² + Dh ² ) / 8) ^0.5 .

FIG. 5 and FIG. 5 show the cross-sectional shape of the blade 3 at a position away from the rotation axis O of the propeller fan 1 by the average radius (R) of the flow path area. FIG. 6 shows a dimensional diagram of the reference cross-sectional shape.

The dimension Lm shown in FIG. 6 is the length of a curve connecting the midpoints in the thickness direction of the wing 3 from the front end to the rear end of the wing 3 in the reference cross-sectional shape. Say. Further, the dimensions t1 and t2 are set to the front end in the rotation direction (the left end in FIG. 6) and the rear end in the rotation direction (FIG.
(Right end) of the wing 3. The relationship between the warp line length Lm and the thicknesses t1 and t2 is (t1 / Lm)
= 0.03, (t2 / Lm) = 0.02.

The wing 3 is a so-called forward wing, and has a shape in which the leading edge is advanced in the rotational direction toward the outer peripheral side in order to improve aerodynamic performance (see FIGS. 3 and 4). Further, a hollow structure is adopted, and the wing 3 is a thick wing (airfoil-shaped wing) and a lightweight wing. Since the wing 3 is a thick wing, its leading edge is rounded (see FIG. 5).
The degree of separation of airflow (air) flowing from various directions can be reduced, particularly the degree of occurrence of leading edge separation.

Specifically, the wing 3 is constituted by a wing body 21 which is a shell and a lid 22. When the wing body 21 and the lid 22 are bonded together by ultrasonic bonding or the like, a hollow portion 3c is formed between the two 21 and 22 (see FIG. 5).

As shown in FIG. 5, the wing body 21 has a sectional shape such that a solid wing is provided with a concave portion 21a.
a, an intermediate thin portion 21b, and a rear portion 3b. Recess 2
A step portion 21c is formed around 1a, and the peripheral end portion of the lid 22 fits into the step portion 21c. As shown in FIG. 1, a projection 23 swelling toward the negative pressure surface side (upper side in FIG. 1) is formed integrally with the outer peripheral portion of the front portion 3a of the wing body 21. The flow of air from the nozzle 22a into the hollow portion 3c is suppressed.

The lid 22 is a thin shell, and has a flat shape with a front edge extending forward on the outer peripheral side. Lid 22
The edge of is drawn a smooth curve, but the outer peripheral front edge,
Discharge ports 22a, 22b, and 22c are formed on the outer peripheral side rear edge and the inner peripheral side rear edge, respectively (see FIG. 1). These outlets 22a, 22b, 22c communicate with the outside of the blade 3 from the hollow portion 3c.

FIG. 7 is a partially enlarged view of the propeller fan 1 as viewed from the back. In FIG. 7, the hollow portion 3c of the wing 3 extends in a range indicated by a dotted line. As is clear from FIG. 7, the length of the blade 3 in the rotation direction becomes shorter toward the inner side in the radial direction, whereas the front end of the hollow portion 3 c in the rotation direction (left end in FIG. 7) and the front end of the blade 3 in the rotation direction also become shorter. Front part 3 of a certain wing body 21
a to the front end in the rotation direction (hereinafter, the width (s) of the front part 3a)
That. ) Is substantially constant in the radial direction, and becomes slightly larger as the distance from the junction between the hub 2 and the blade 3 approaches. This means that the length of the blade 3 in the rotation direction is substantially proportional to the warp line length (L) of the blade 3 at each radial position.
(S / L) of the width (s) to the warpage line length (L)
Is closer to the junction between the hub 2 and the wing 3.

Also, while the radial change of the thickness t of the blade 3 at the position of the front end in the rotation direction of the hollow portion 3c is small,
The length of the blade 3 in the rotation direction changes so as to become smaller toward the inner circumferential side, and the change is greater than the change in the thickness (t) of the blade 3 in the radial direction. That is, the warp line length (L) of the wing 3
And the thickness (t) of the blade 3 (t / L) increases toward the inner peripheral end.

In this embodiment, first, (t1 / Lm) = 0.03 (t2 / Lm) = 0.02 in the reference sectional shape. This ratio secures the thickness (t1) of the blade 3 at the position where the hollow portion 3c starts and the thickness (t2) of the blade 3 at the position where the hollow portion 3c ends when viewed from the front side in the rotation direction, and the strength is insufficient. This is a value at which strength can be obtained in a portion where a hollow portion is easily formed. Further, this ratio is controlled by keeping the thickness (t1) and the thickness (t2) small.
The hollow portion 3c is formed up to a relatively thin portion of
The purpose is to reduce the weight of the wing 3. As a result, the weight of the propeller fan 1 is reduced, and the weight reduction of the wing 3 leads to the saving of the raw material of the wing 3, so that the manufacturing cost of the propeller fan 1 is reduced. in this way,
The propeller fan 1 of the present embodiment retains the advantage of weight reduction to a fan having a blade having a solid structure to some extent, and also secures the strength of the blade 3.

Here, (t1),
Although the dimensional relationship of (t2) and (Lm) is satisfied, a solid structure is provided within a range of 0.02 ≦ (t1 / Lm) ≦ 0.10 0.01 ≦ (t2 / Lm) ≦ 0.08. The advantage of weight reduction with respect to the fan having the blades is maintained to some extent, and the blade strength is also ensured. Further, the propeller fan 1 of the present embodiment
Has an outer diameter (Do) of 450 mm, but an outer diameter of 250 m
It has been confirmed that the same effect can be obtained with a propeller fan made of resin having a diameter of m to 700 mm.

In the present embodiment, the length of the warp line (L) of the blade 3 and the position of the blade 3 at the front end in the rotation direction of the hollow portion 3c are also determined.
The ratio (t / L) to the thickness (t) of the inner peripheral end (hub 2
Side). For this reason, it is possible to secure the strength near the joint with the hub 2 in the front portion 3a of the wing body 21 to which a high tensile force or the like is applied by centrifugal force or the like. This suppresses damage to the blades 3 during rotation of the propeller fan 1. On the other hand, in other portions where only a relatively small force is applied, the hollow portion 3c is formed to a range where the thickness of the blade 3 is relatively thin, so that the weight of the blade 3 is reduced.

In this embodiment, the ratio (s / L) of the width (s) of the front portion 3a to the length (L) of the warp line is increased as the distance from the hub 2 is increased. )
Wing 3 is a forward wing which becomes smaller as it approaches hub 2
Even so, the cross-sectional area of the front part 3a is ensured to some extent. Thereby, damage to the blades 3 during rotation of the propeller fan 1 is suppressed.

In this embodiment, since the wing 3 having the hollow structure has a two-body structure of the wing body 21 and the lid 22, the shape of the hollow portion 3c (the front end and the rotation direction) is smaller than that of the air-assist type wing. Position of the rear end in the rotation direction) can be formed accurately. Therefore, the weight of the wing 3 is appropriately reduced while ensuring the strength corresponding to the force applied to each part of the wing 3.

[Second Embodiment] A blade 103 of a propeller fan according to a second embodiment of the present invention.
FIG. 8 shows a cross-sectional view at the average diameter of the flow channel area. The propeller fan of the present embodiment is used for blowing air in an outdoor unit 10 for an air conditioner as shown in FIGS. 2 and 3.

In the following description, the description of the same components as in the first embodiment will be omitted. The propeller fan 1 includes a hub and a plurality of blades 10 joined to an outer peripheral surface of the hub.
And 3.

The wing 103 includes a wing main body 121 as a shell and a lid 122. When the wing main body 121 and the lid 122 are bonded together by ultrasonic bonding or the like, a hollow portion 103c is formed between the two 121 and 122 (see FIG. 8).

As shown in FIG. 8, the wing body 121 has a sectional shape such that a concave portion 121a is provided on the negative pressure surface side of a solid wing, and includes a front portion 103a, an intermediate thin portion 121b, and a rear portion 103b. . A step 12 is formed around the recess 121a.
1c is formed, and a lid 122 is
The peripheral end portion of the is stuck.

The lid 122 is a thin shell, and includes a central thin portion (central portion) 122e and a peripheral portion 122d located around the central thin portion 122e. Lid 122
Is made of resin and has a central thin portion 122e and a peripheral portion 122e.
d is formed integrally. The thickness of the peripheral portion 122d is smaller than the thickness of the central thin portion 122e. The outer peripheral end portion of the peripheral edge portion 122d is fitted into the step portion 121c of the wing main body 121, and both are joined by ultrasonic welding.

The other structure is the same as that of the first embodiment. The propeller fan of the present embodiment employs the lid 122 in which the central thin portion 122e, which has a smaller stress than the peripheral portion 122d, is thinner if the thickness is the same. Thus, the weight of the lid 122 is reduced, and the weight of the propeller fan is reduced.

In the first and second embodiments, the joining between the wing bodies 21 and 121 and the lids 22 and 122 is not an all-around joining. This is because a structure is adopted in which the strength of the wing 3 is mainly given to the wing bodies 21 and 121, and therefore, the lids 22 and 122 are attached to the wing bodies 21 and 1.
It is thinner than 21.

[Other Embodiments] In each of the above embodiments, the blade 3 is made of resin. However, the present invention can provide the same effect when applied to a metal blade and a propeller fan.

[0043]

In the impeller for a blower according to the present invention, the thickness of the blade at the position where the hollow portion of the blade starts and the thickness of the blade at the position where the hollow portion of the blade ends, as viewed from the front side in the rotational direction, are set to predetermined values. By securing only the thickness and suppressing the thickness to a predetermined value or less, the advantage of weight reduction with respect to the impeller for the blower having the blade of the solid structure is maintained to some extent, and the strength of the blade is also secured.

[Brief description of the drawings]

FIG. 1 is a perspective view of a propeller fan according to an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view of the outdoor unit for an air conditioner.

FIG. 3 is a front view of an outdoor unit for an air conditioner.

FIG. 4 is a plan view of a propeller fan.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a sectional dimensional view of a wing.

FIG. 7 is a partially enlarged rear view of the propeller fan.

FIG. 8 is a sectional view of a wing according to a second embodiment.

[Explanation of symbols]

Reference Signs List 1 propeller fan (impeller for blower) 2 hub 3,103 blade 3a, 103a front part 3b, 103b rear part 3c, 103c hollow part 21,121 blade body 22,122 lid 122d peripheral part 122e central thin part (central part) R Average flow path area radius (= D / 2) D Average flow path area diameter Do External diameter of propeller fan at average flow path area diameter Dh External diameter of hub at average flow path area diameter L Length of warpage of blade Lm Warp line length of blade at average flow path area diameter s Width of front part of blade body t Thickness of blade at front end of hollow section in rotation direction t1 Position of front end of hollow section at average flow path area diameter in rotation direction Of the blade at t2 Thickness of the blade at the position of the front end in the rotation direction of the hollow portion at the average diameter of the flow path area

────────────────────────────────────────────────── ─── Continuation of the front page (72) Eiichi Kitano 1304, Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd. Sakai Plant Kanaoka Plant (56) References JP-A-10-47298 (JP, A) JP Hei 6-264898 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F04D 29/38

Claims (4)

(57) [Claims] An impeller (1) for a blower comprising a hub (2) and a blade (3) having a hollow portion (3c) therein, wherein the outer diameter is Do and the hub (2) When the outer diameter is Dh, in the cross-sectional shape of the blade (3) at the flow path area average diameter expressed by D = ((Do ² + Dh ² ) / 2) ^0.5 , the warpage of the blade (3) The relational expression between the length Lm and the thickness t1 of the blade (3) at the position of the front end in the rotation direction of the hollow portion (3c) is 0.02 ≦ (t1 / Lm) ≦ 0.10. The relational expression between the length Lm and the thickness t2 of the blade (3) at the position of the rear end in the rotation direction of the hollow portion (3c) is 0.01 ≦ (t2 / Lm) ≦ 0.08, for a blower Impeller (1). 2. A hub (2) and a plurality of blades (3) having an inner peripheral end attached to said hub (2) and having a hollow portion (3c) inside.
An impeller for a blower (1) comprising: a hollow portion (3) with respect to a warp line length L of the blade (3).
The impeller (1) for a blower, wherein the ratio (t / L) of the thickness t of the blade (3) at the position of the front end in the rotation direction in (c) becomes larger as approaching the inner peripheral end. 3. A hub (2) and a plurality of blades (3) having an inner peripheral end attached to said hub (2) and having a hollow portion (3c) inside.
And a distance between a front end of the hollow portion (3c) and a front end of the blade (3).
An impeller (1) for a blower , wherein the separation (s) increases as approaching a mounting portion of the wing (3) and the hub (2). 4. The wing (3) comprises a wing body (21) and a lid (2).
2), and a space surrounded by the wing body (21) and the lid (22) is a hollow portion (3).
The impeller (1) for a blower according to any one of claims 1 to 3, which is c).