JP4918650B2 - Multi-wing fan - Google Patents

Description

  The present invention relates to a structure of a blade portion of an impeller of a multiblade fan.

  For example, multi-blade fans such as crossflow fans, sirocco fans, and turbo fans are generally used as blowers for air conditioners.

  Now, for example, FIG. 9 shows a wall-mounted air conditioner A configured using the multiblade fan 3 as a blower.

  The air conditioner A includes a main body casing 1 having an air suction port 4 on the upper surface and an air outlet 5 on the lower surface front portion, a lambda-shaped heat exchanger 2 disposed in the main body casing 1, And a multi-blade fan 3 disposed on the secondary side of the heat exchanger 2.

  The heat exchanger 2 includes a front-side heat exchange part 2a through which an air flow supplied from an air suction port 4 through an air passage 6 formed on the front side and the upper side of the main casing 1 passes, and the front-side heat It consists of a back surface side heat exchanging portion 2b that is connected to the upper end of the exchanging portion 2a and is located on the back side.

  On the other hand, reference numeral 8 denotes a first drain pan that receives the drain from the front side heat exchange unit 2a, 9 denotes a second drain pan that receives the drain from the back side heat exchange unit 2b, and 10 denotes a blade of the multiblade fan 3 A guide portion for guiding the air flow blown out from the car 7, 11 is a backflow preventing tongue for preventing the backflow of the air flow blown out from the impeller 7, and 12 is provided in the upstream portion of the air outlet 5. The vertical blades 13 are horizontal blades arranged in the downstream portion of the air outlet 5.

  The air flow sucked from the air suction port 4 is cooled or heated when passing through the heat exchanger 2 to become conditioned air. For example, as shown in FIG. 11, the impeller 7 of the multiblade fan 3 is used. Is blown into the room from the air outlet 5 (see the arrow).

  For example, as shown in FIG. 10, the impeller 7 of the multiblade fan 3 is parallel to the rotary shaft 16 at the outer peripheral edge portions of a plurality of circular support plates arranged in parallel at predetermined intervals in the direction of the rotary shaft 16. Are arranged in a forward blade structure with a predetermined blade angle so that a plurality of blades (blades) 15, 15.

  In such an impeller 7 of the multiblade fan 3, aerodynamic noise generated by the air flow passing through the blades 15, 15. The main causes of this aerodynamic noise include separation of the air flow on the suction surface side of the blades 15, 15... And wake vortex generated on the blade trailing edge side.

  Therefore, as a method of reducing the aerodynamic noise of the impeller 7 of the multiblade fan 3 as described above, the outer peripheral side blades of the blades 15, 15. .. Are provided intermittently at the ends 15 a, 15 a... Via the smooth portions 18, 18..., Or continuously at the blade tips 15 a, 15 a. A method of reducing noise by reducing the wake vortex generated on the trailing edge side of the blade at the time of blowing is proposed (for example, Patent Documents 1 and 2). Etc.).

JP-A-3-249400 JP-A-11-141494

  However, in these configurations, for example, as can be understood from FIGS. 14 and 15, for example, the same shape and the same depth over both the pressure surface side and the suction surface side of the outer peripheral side blade tips 15 a, 15 a. Since there are notches 17, 17... Of the same angle (D1 = D2, the left and right notched surfaces 17a, 17a are straight in the direction of the other surface), at the time of blowing, FIG. The portion with the notch portion 17 shown in (a) of FIG. 16 expands before the exit of the blade 15 is sufficiently oriented in the circumferential direction of the fan as compared with the portion (flat smooth portion 18) shown in FIG. 16 (b). For this reason, the fan blowout flow is not sufficiently directed in the circumferential direction, the speed of the blown airflow is reduced, and the pressure is lowered. As a result, there is a problem that it becomes weak against pressure loss of a filter or the like, and it becomes difficult to produce an effective air volume.

  The present invention has been made to solve such a problem, and in a multiblade fan in which notches are provided intermittently or continuously at the blade outer peripheral blade tip, the shape of the notch is changed to the pressure surface side and the suction surface. To provide a multiblade fan that can effectively increase the pressure of the blown flow by increasing the speed of air passing through the notch as much as possible by making it different from the side It is intended.

  The present invention has been made for the purpose of solving the above problems, and comprises the following effective problem solving means.

(1) first means for solving problems of the first means for solving problems The present invention, only setting the intermittent or continuous notched portions 27, 27 ... on the outer circumference side tip 15a of the blade 15, the cutout portion 27 In the multiblade fan in which the shapes of the blade pressure surface side and the suction surface side are different , the shape of the notches 27, 27... Is substantially triangular, and the triangle on the blade pressure surface side. The area is formed larger than the area of the triangle on the suction surface side .

  According to such a configuration, the left and right surfaces of the pressure surface side notches 27, 27... Become tapered surfaces, thereby increasing the speed of the air flow passing through the notches 27, 27. This makes it easier to direct the flow of air blown from the fan in the circumferential direction, so that the fan pressure can be increased more effectively.

(2) Second Problem Solving Means The second problem solving means of the present invention is provided with notches 27, 27... Intermittently or continuously on the outer wing tip 15a of the blade 15, and the notches 27, 27. In the multiblade fan in which the shape of 27... Is different between the blade pressure surface side and the suction surface side, the shape of the notches 27, 27. The area is smaller than the area of the triangle on the suction surface side .

  According to such a configuration, the groove portions of the pressure surface side cutout portions 27, 27... Can be reduced, thereby increasing the speed of the air flow passing through the cutout portions 27, 27. It becomes easier to direct the flow of air blown out in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(3) Third problem solving means The third problem solving means of the present invention is provided with notches 27, 27... Intermittently or continuously on the outer wing tip 15 a of the blade 15. In the multiblade fan in which the shape of 27... Is different between the blade pressure surface side and the suction surface side, the shape of the notches 27, 27. The area is larger than the area of the trapezoid on the suction surface side .

  Even in such a configuration, the left and right surfaces of the pressure surface side cutout portions 27, 27... Become tapered surfaces, thereby increasing the speed of the air flow passing through the cutout portions 27, 27. It is possible to easily direct the air flow blown from the fan in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(4) Fourth Problem Solving Means According to a fourth problem solving means of the present invention, the notch portions 27, 27... Are provided intermittently or continuously on the outer wing tip 15a of the blade 15, and the notch portions 27, 27,. In the multiblade fan in which the shape of 27... Is different between the blade pressure surface side and the suction surface side, the shape of the notches 27, 27. The area is smaller than the trapezoidal area on the suction surface side .

  According to such a configuration, the groove portion of the pressure side cutout portions 27, 27... Can be reduced, thereby increasing the speed of the air flow passing through the cutout portions 27, 27. It becomes easy to direct the flow of the blown-out air in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(5) Fifth Problem Solving Means The fifth problem solving means of the present invention is provided with notches 27, 27... Intermittently or continuously on the outer wing tip 15a of the blade 15, and the notches 27, 27. In the multiblade fan in which the width of 27 ... differs between the blade pressure surface side and the suction surface side, the change in the width in the depth direction of the notches 27, 27 ... is continuous. It is a feature .

  According to such a configuration, the right and left notch surfaces of the pressure surface side notches 27, 27... Described above become continuous tapered surfaces having a constant inclination angle, and thereby the notches 27, 27. The speed of the passing air flow can be increased efficiently, and the air flow blown from the fan can be more easily directed in the circumferential direction. As a result, the fan pressure can be increased more effectively.

  In the above configuration, even in the case where there is a resistance such as a filter by increasing the speed of the air passing through the notch and effectively increasing the pressure in the multiblade fan provided with the notch at the blade outer peripheral side end. A predetermined amount of airflow can be produced.

  Further, since the two-dimensionality of the blade outer peripheral end can be eliminated, the wake vortex generated on the blade trailing edge side at the time of blowing can be reduced, and the noise can be reduced.

  Therefore, the air conditioner is optimal as a blower for an air conditioner, for example, a cross flow fan for an air conditioner, and a high-performance air conditioner having a stable and constant air flow rate and high quietness can be provided. .

  Hereinafter, some preferred embodiments of the present invention will be described with reference to the accompanying drawings.

(Best Embodiment 1)
First, FIGS. 1 to 4 show a configuration of a blade portion of an impeller of a multiblade fan according to Embodiment 1 of the present invention.

  The multi-blade fan impeller of this embodiment also has a plurality of circular support plates 14 arranged in parallel at a predetermined interval in the direction of the rotation axis 16 as in the conventional example (see FIG. 10). .. Are arranged in a forward blade structure with a predetermined blade angle so as to be parallel to the rotating shaft 16 at the outer peripheral edge of. It is configured.

  The outer wing tips 15a of the blades 15, 15... Have a number of substantially triangular notches 27, 27,. Are formed, and smooth portions (non-notched portions) 18, 18... Having a predetermined width constituting part of the blade tip are provided between the notched portions 27, 27. Yes.

  In this way, a large number of substantially triangular notches 27, 27... Are formed at predetermined intervals on the outer wing tip 15a of the blade 15, and a predetermined interval is formed between the notches 27, 27. When the smooth portions 18, 18... Of the width are provided, for example, when used as a cross flow fan as shown in FIG. Since the vortex is formed by the vertical vortex formed by the notches 27, 27,..., The scale is organized small and subdivided into a stable lateral vortex, so that aerodynamic noise can be effectively reduced. There are benefits.

  However, as described above, in the configuration in which the notches 27, 27,... Are simply provided, the notches 27, 27,. The fan outlet flow is not sufficiently directed in the circumferential direction because the blade outlet is expanded before it is sufficiently oriented in the circumferential direction of the fan as compared with the portion without the cutout portions 27, 27. , The speed decreases and the pressure decreases.

  As a result, there arises a problem that it becomes weak against pressure loss of a filter or the like, and it becomes difficult to produce an effective air volume.

  In this case, the greater the number of notches 27, 27... Provided in the blade 15, and the greater the size of the notches 27, 27.

  Therefore, in this embodiment, in order to solve such a problem, the shape of the notches 27, 27... Is different between the blade pressure surface side and the suction surface side.

  In this way, in the multiblade fan 3 in which the outer peripheral blade tip 15a of the blade 15 is provided with the notches 27, 27... Intermittently or continuously, the shape of the notches 27, 27. If the pressure surface side and the suction surface side are different, the blade outlet angle of the cross section at the position where the cutout portions 27, 27... Are present, and the blade tip 15a has no cutout portions 27, 27. It can be directed in the circumferential direction as in the case of the broken line), and the fan pressure can be increased.

  As a result, even when there is a resistance such as a filter, it becomes possible to produce a predetermined air volume, which is more than a conventional blade provided with notches 17, 17... Having the same shape on both the positive and negative pressure sides. In addition, since a blower with the same air volume can be realized with low rotation, noise due to rotation of the fan can be reduced.

  Further, since the two-dimensionality of the outer peripheral blade tip 15a of the blade 15 can be eliminated, the wake vortex generated on the blade trailing edge side during blowing can be reduced, and the noise can be effectively reduced.

(Example)
As described above, when the shape of the cutout portions 27, 27... Of the outer peripheral side blade tips 15a, 15a... Of the blade 15 is changed between the pressure surface side and the suction surface side, as a specific example thereof, For example, the following various shapes can be considered.

(1) Example 1
The shape of the groove portions of the notches 27, 27... Is generally a triangle as described above. For example, as shown in FIGS. 1 and 2, the blade pressure surface side triangle (FIG. 2B). ) Is sufficiently larger than the area of the triangle on the suction surface side (FIG. 2A).

  In this case, as shown in FIG. 3, the depth (the depth in the chord direction) of each notch 27 on the pressure side and the suction side is exactly the same (D1 = D2).

  According to such a configuration, the left and right cut-out surfaces (groove surfaces) of the pressure-side cut-out portions 27, 27... Become wide tapered surfaces as shown in FIG. As shown, the speed of the air flow passing through the notches 27, 27... Can be increased, and the air flow blown from the fan can be easily directed in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(2) Example 2
The shape of the notches 27, 27... Is substantially triangular as in the case of the first embodiment. However, in contrast to the first embodiment, the area of the triangle on the blade pressure side is smaller than the area of the triangle on the suction side. Also make it small.

  According to such a configuration, the width of the groove portion of the pressure side cutout portions 27, 27... Is reduced, while the left and right surfaces of the cutout portions 27, 27. Can increase the speed of the air flow passing through the notches 17, 17..., And the air flow blown from the fan can be easily directed in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(3) Example 3
The shape of the notches 17, 17... Is substantially trapezoidal, and the area of the trapezoid on the blade pressure surface side is formed larger than the area of the trapezoid on the suction surface side.

  Even with such a configuration, as in the case of the first embodiment, the left and right cutout surfaces of the blade pressure surface side cutout portions 17, 17... Become wide tapered surfaces, thereby forming the cutout portions 17, 17. .. The speed of the air flow passing through can be increased, and the air flow blown out from the fan can be easily directed in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(4) Example 4
The shape of the notches 27, 27... Is substantially trapezoidal as in the case of the third embodiment, but the trapezoid area on the blade pressure surface side is a trapezoid on the suction surface side, contrary to the case of the third embodiment. It is formed smaller than the area.

  According to such a configuration, the width of the groove portions of the notches 27, 27... On the blade pressure surface side is reduced, while the left and right surfaces of the notches 27, 27. Thus, the speed of the air flow passing through the pressure side cutouts 27, 27... Can be increased, and the air flow blown from the fan can be easily directed in the circumferential direction. As a result, the fan pressure can be increased more effectively.

(Best Mode 2)
Next, FIGS. 5 to 8 show the configuration of the blade portion of the impeller of the multiblade fan according to Embodiment 2 of the present invention.

In this embodiment, the cutout portions 27, 27... Are intermittently provided on the outer peripheral blade tip 15a of the blade 15 via the smooth portions 18, 18,. In the multiblade fan, the shape of the notches 27, 27... Is the same on the pressure surface side and the suction surface side, but the width of the groove 27b is as shown in FIGS. The blade positive pressure surface side is large and the blade negative pressure surface side is small .

In this case, the change in the width in the depth direction from the pressure surface side to the suction surface side of the groove portion 27b of the notches 27, 27... Is continuous as shown in FIGS. Is preferred.

  According to such a configuration, the left and right groove surfaces of the notches 27, 27... Are not straight cut surfaces as in the conventional example shown in FIGS. 14 (a), 14 (b) and FIG. As shown in FIG. 6, the notch surface on the pressure side becomes a wide tapered surface (see FIG. 6B), thereby effectively reducing the velocity of the air flow passing through the notches 27, 27. For example, the fan pressure can be effectively increased by directing the flow of air blown from the fan in the circumferential direction as indicated by the arrow in FIG.

  As a result, even when there is resistance such as a filter, it becomes possible to output a predetermined air volume, which can be realized at a lower rotation than a conventional blade having a notch, so that noise due to fan rotation is reduced. You can also.

  Further, since the two-dimensionality of the outer peripheral blade tip 15a of the blade 15 can be eliminated, the wake vortex generated on the blade trailing edge side during blowing can be reduced, and the noise can be effectively reduced.

In the case where the width of the notches 27, 27... Is different between the pressure surface side and the suction surface side of the blade 16, the width is, for example, the blade pressure surface side. It can be made smaller and larger on the blade suction surface side.

  In such a case, as can be understood from the relationship between FIGS. 6A and 6B described above, the size of the groove 27b of the notch 27 on the pressure surface side is reduced, and the pressure surface side is correspondingly reduced. The speed of the air flow passing through the notches 27, 27... Can be increased, and the fan pressure can be effectively increased by directing the air flow blown from the fan in the circumferential direction.

  As a result, even when there is resistance such as a filter, it becomes possible to output a predetermined air volume, which can be realized at a lower rotation than a conventional blade having a notch, so that noise due to fan rotation is reduced. You can also.

(Best Mode 3)
In addition, the above-described configuration of the first embodiment, that is, the notch portions 17, 17... Are provided intermittently (or continuously) on the outer peripheral blade tip 15a of the blade 15 and the notches 17, 17,. In the multiblade fan in which the shape of the blade pressure surface side and the suction surface side are different, the depth of the notches 17, 17.. It is also possible to combine configurations that are different on the side and the suction surface side.

  If it does so, the effect | action of both will synergize and a fan pressure will rise more effectively.

It is a perspective view (pressure surface side) which shows the whole structure of the blade | wing part of the impeller of the multiblade fan which concerns on best Embodiment 1 of this invention. Enlarged view of blade outer edge (notch) viewed from blade outer edge side to notch direction showing configuration of main part of blade ((a) view from suction surface side, (b) pressure surface side Figure seen from). It is sectional drawing (cross-sectional view) of the cutting | disconnection part of the blade inside and outside direction in the notch part position of the blade. It is sectional drawing which shows the effect | action at the time of the impeller structure in the notch part position of the blade. It is a perspective view (pressure surface side) which shows the structure of the blade | wing of the impeller of the multiblade fan which concerns on best Embodiment 2 of this invention. Enlarged view of blade outer edge (notch) viewed from blade outer edge side to notch direction showing configuration of main part of blade ((a) view from suction surface side, (b) pressure surface side Figure seen from). It is sectional drawing (cross-sectional view) of the cutting | disconnection part of the blade inside and outside direction in the notch part position of the blade. It is sectional drawing which shows the effect | action at the time of the impeller structure in the notch part position of the blade. It is a longitudinal cross-sectional view which shows the structure of the conventional general wall-hanging type air conditioner which is an application example of the impeller which consists of a multiblade fan. It is a perspective view which shows the whole structure of the impeller which consists of the multiblade fan. It is a figure which shows the state of the blowing air flow in the blade | wing of the impeller which consists of the multiblade fan. It is a top view which shows the structural example of the blade | wing of the prior art example in the impeller of the multiblade fan. It is a whole perspective view (pressure surface side) which shows the arrangement | positioning state of the notch part of the blade outer peripheral edge part of the impeller of the multiblade fan. It is a figure which shows the notch part shape (a) seen from the suction surface side of the blade | wing of the multiblade fan, and the notch part shape (b) seen from the pressure surface side. It is sectional drawing (cross-sectional view) of the cut part cut | disconnected in the blade front-back direction which shows the structure of the notch part of the blade | wing of the multiblade fan. The state of the flow of air on the blowout side of the inter-blade part of the impeller of the multiblade fan (cross-section part A-A in FIG. 12 and cross-section part BB in FIG. 12) is shown. It is explanatory drawing (when there is a case where there is no notch part).

  3 is a multi-blade fan (cross flow fan), 7 is an impeller, 10 is a guide part, 11 is a tongue part, 14 is a circular support plate, 15 is a blade, 15a is a blade end part on the outer periphery of the blade, 15b is inside the blade A peripheral blade tip, 16 is a rotating shaft, 17 and 27 are notched portions, 18 is a smooth portion, 27a is a tapered surface portion, and 27b is a groove portion.

Claims (5)

Intermittently or continuously notch on the outer peripheral side tip of the blade (15) (15a) (27), only set (27) ..., the notch (27), the shape of the (27) ... In the multiblade fan that is different between the blade pressure surface side and the suction surface side, the shape of the notches (27), (27)... Is substantially triangular, and the area of the triangle on the blade pressure surface side is negative. A multiblade fan characterized in that it is formed larger than the area of a triangle on the pressure side . The notches (27), (27), ... are provided intermittently or continuously on the outer wing tip (15a) of the blade (15), and the shape of the notches (27), (27),. In the multiblade fan that is different between the pressure surface side and the suction surface side, the shape of the notches (27), (27)... Is substantially triangular, and the area of the triangle on the blade pressure surface side is the suction surface. A multiblade fan characterized by being formed smaller than the area of the triangle on the side . The notches (27), (27), ... are provided intermittently or continuously on the outer wing tip (15a) of the blade (15), and the shape of the notches (27), (27),. In the multiblade fan that is different between the pressure surface side and the suction surface side, the shape of the notches (27), (27)... Is substantially trapezoidal, and the trapezoid area on the blade pressure surface side is the suction surface. A multiblade fan characterized in that it is formed larger than the area of the trapezoid on the side . The notches (27), (27), ... are provided intermittently or continuously on the outer wing tip (15a) of the blade (15), and the shape of the notches (27), (27),. In the multiblade fan that is different between the pressure surface side and the suction surface side, the shape of the notches (27), (27)... Is substantially trapezoidal, and the trapezoid area on the blade pressure surface side is the suction surface. A multiblade fan characterized by being formed smaller than the area of the trapezoid on the side . The notches (27), (27)... Are provided intermittently or continuously on the outer wing tip (15a) of the blade (15), and the width of the notches (27), (27). In the multiblade fan that is different between the pressure surface side and the suction surface side, the change in the width in the depth direction of the notches (27), (27), ... is continuous. Wing fan.

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