JP5357492B2 - Propeller fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propeller fan enabling implementation of deformation prevention and weight reduction of the propeller fan, and maintenance, improvement and the like of basic performances such as blowing performance, efficiency, and noise performance. <P>SOLUTION: In the propeller fan 1 made of a resin comprises a hub 2, and a plurality of blades 3 radically provided around the outer periphery of the hub 2, the propeller fan includes a ring 10 for coupling the blades 3 one another at an inner peripheral position from the outer periphery 6 of the blades 3, parts of the ring 10 is removed by notches 12, 12A, 14 between leading edges 4 and/or trailing edges 5 of the neighboring blades 3 at the upstream side end edge 13 and/or the downstream side end edge 11 in the ventilation direction. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a resin propeller fan including a cylindrical hub and a plurality of blades radially provided on the outer periphery of the hub.

  Plastic propeller fans that are applied to cooling fans such as radiators for automobile engines and condensers for air conditioning are installed in a narrow engine room and require weight reduction. (Dimensions) cannot be increased. For this reason, the depth dimensions of blades, hubs, shrouds and the like constituting the propeller fan are made as thin as possible. In addition, the size of the gap between the device to be ventilated such as the radiator and the condenser is made as small as possible, and both are arranged close to each other.

  As described above, the size of the gap between the device to be ventilated is minimized because the cooling fan is placed in a severe operating environment that is affected by vibration, high temperature, water pressure caused by water splashed during running in a submerged channel, etc. Therefore, interference with a radiator, a capacitor, or the like due to blade deformation or the like is induced. In particular, a thin resin propeller fan that rotates at a high speed is easily deformed in shape and may cause a serious accident due to interference with a core portion such as a radiator or a capacitor. As a means for preventing deformation of the thin resin propeller fan in the rotation axis direction, as shown in Patent Documents 1 and 2, in addition to increasing the thickness of the blade and increasing the strength, The structure which couple | bonds the outer periphery part of this with a ring is known.

  The above ring can suppress air flow from the outer periphery of the blade in the centrifugal direction and air leakage due to pressure difference from the pressure surface side of the blade to the negative pressure surface side. It is. Further, in order to avoid an increase in the surface area of the ring, those in which the width of the ring is smaller than the width of the blade are shown in Patent Documents 1 and 2, and furthermore, only the outer peripheral end of each blade is equivalent to a ring. Japanese Patent Application Laid-Open No. H10-228473 discloses a device provided with auxiliary wings.

  In addition, as described above, in a propeller fan with a reduced depth dimension, the cross-sectional shape of the shroud that guides air to the propeller fan also changes abruptly, and the air flow that has passed through the radiator and condenser is caused by the inertial force. In order to suppress the centripetal flow toward the side, and in order to suppress this, Patent Document 4 proposes an auxiliary blade erected in the axial direction concentrically with a bell mouth provided on the shroud from the suction surface of the blade.

JP 2005-106003 A JP 2007-92562 A JP 2000-314394 A JP 2007-40197 A

  However, as shown in Patent Documents 1 and 2, in the configuration in which the outer peripheral edges of the blades are coupled by a ring, even if the ring width is reduced, the circumference of the ring itself is increased. Since it becomes large and heavy, there is a problem that it is contrary to weight reduction. In addition, since the propeller fan restricts the shape of the outermost peripheral part of the blade having the best blowing efficiency, there is a problem that the basic performance of the propeller fan such as blowing performance, efficiency and noise performance is deteriorated. It was.

  Furthermore, since the blades shown in Patent Documents 3 and 4 are provided with auxiliary blades for each blade, fan performance and noise performance equivalent to a fan with a ring can be obtained, and the surface area can be reduced compared to the ring, resulting in fan efficiency. And the like can be improved. However, the auxiliary wing provided for each blade loses its function as a ring for connecting the blades, so that there is a problem that the effect of increasing the rigidity against deformation of each blade in the rotation axis direction cannot be expected.

  The present invention has been made in view of such circumstances, and it is possible to achieve the prevention and deformation of the propeller fan, and the maintenance and improvement of basic performance such as blowing performance, efficiency and noise performance. An object is to provide a propeller fan that can be used.

In order to solve the above problems, the propeller fan of the present invention employs the following means.
That is, the propeller fan according to the present invention is a resin-made propeller fan having a hub and a plurality of blades radially provided on the outer periphery of the hub. comprises a ring that binds together the inner peripheral side position also, the ring, one between the leading each other and trailing edges cross the blades that are adjacent to each other of the upstream edge and the lower stream side edge of the ventilating direction Part is deleted by a notch, the upstream edge provided on the suction surface side that is close to the ventilation target device ventilated by the propeller fan and is likely to be peeled off on the blade surface. The notch has a smooth convex curve at a portion corresponding to the front of the blade leading edge in the rotational direction, and has a stall suppressing function at least near the outer periphery of the blade. Characterized in that the raising wall erected axially from pressure surface, smooth height towards the trailing edge from the leading edge of the blade is removed leaving the aileron substantial portion provided so as to increase And

According to the present invention, a plurality of blades between comprises a ring that binds together the inner peripheral side position of the outer peripheral edge of the blade, adjacent the upstream edge and the lower stream side edge of the ventilating direction of the ring because you are deleted by notches part between the front edge each other and trailing edges mutually to have a blade, increasing the thickness of the rigid blade relative deformation in the rotation axis direction of each blade by the ring Can be raised without any. In addition, since the ring is provided at a position on the inner peripheral side with respect to the outer peripheral edge of the blade, the ring suppresses the centripetal flow at the outer peripheral part of the blade, and as an auxiliary blade having an effect of suppressing the stall near the outer peripheral edge of the blade. It functions, and its rectifying effect can maintain and improve the basic performance of the propeller fan, such as the blowing performance, efficiency and noise performance, and at the same time, the ring circumference can be shortened. The weight can be reduced by making it as small as possible. In addition, since the remove the portion provided with the notches on the upstream edge and the lower stream side edge of the ring, it is possible to reduce the weight of the volume equivalent was deleted by notch. As a result, the basic performance of the propeller fan can be maintained and improved, the rigidity against deformation in the direction of the rotation axis can be increased, and the weight can be reduced. In addition, the notch portion on the upstream edge provided on the suction surface side, which is close to the target device to be ventilated by the propeller fan and is likely to be peeled off on the blade surface, is forward in the rotational direction of the blade leading edge. The corresponding wall has a smooth convex curve, and at least the rising wall that stands in the axial direction from the suction surface that has a stall suppressing function near the outer periphery of the blade extends from the front edge of the blade to the rear edge. The upstream edge of the ring is in contact with the ventilated target device due to unforeseen circumstances such as an accident. However, the notch on the ring side does not get caught in the target ventilation target, and even if the propeller fan and the target ventilation target come into contact with each other in the event of an abnormality, the mutual damage can be minimized. The ring provided mainly for the purpose of increasing the rigidity against the deformation of the blade in the axial direction can have a function as an auxiliary wing having a stall suppressing effect in the vicinity of the outer peripheral edge of the blade. It is possible to simultaneously reduce the weight of the propeller fan by providing a notch in the ring, and maintain and improve the basic performance such as fan performance, efficiency and noise performance by making the ring act as an auxiliary wing. .

Furthermore, the propeller fan of the present invention is the above-described propeller fan, wherein the notch portion provided at the downstream end edge of the ring includes a rear edge of the blade adjacent to each other and a front edge of the blade. The entire area on the pressure surface side between the rearward direction in the rotational direction of the connecting line and the trailing edge of the blade is maximized and deleted within a range according to the strength required for the blade. And

  According to the present invention, the notch provided in the downstream edge of the ring has a rear edge of the blade from the rear direction in the rotational direction of a line connecting the rear edge of the blade adjacent to the front edge of the blade. Since the entire area on the pressure surface side up to the maximum is removed within the range according to the strength required for the blade, the range where the ring is removed by providing a notch is adjacent to each other Set the appropriate range by maximizing the substantially entire area on the pressure surface side from the rear direction in the rotation direction of the line connecting the trailing edge of the blade to the leading edge of the blade to the trailing edge of the blade Can do. That is, when priority is given to increasing the rigidity of the blade against deformation, priority is given to securing strength by making the notch provided in the downstream edge of the ring shallower and smaller. On the other hand, when priority is given to weight reduction, weight reduction can be prioritized by increasing the volume equivalent to be deleted by deepening and increasing the notch. Therefore, it is possible to increase the degree of freedom in selecting whether to give priority to securing strength or reducing weight according to the use environment or the like.

  Furthermore, the propeller fan of the present invention is characterized in that, in any of the above-described propeller fans, a protrusion or a protrusion that disturbs the air flow is provided on the outer peripheral surface side of the ring.

  According to the present invention, since the protrusion or protrusion that disturbs the air flow is provided on the outer peripheral surface side of the ring, the air flow around the outer peripheral surface of the ring that is likely to be unstable is caused by the protrusion or protrusion. Can be randomly disturbed. Therefore, it is possible to suppress the generation of sound having a specific frequency component due to an unstable air flow. In addition, a support beam for supporting the drive motor is generally provided on the downstream side of the fan. However, since the distance from the support beam is continuously changed by protrusions or ridges, generation of periodic sounds is also suppressed. Can do. Further, by finely adjusting the height of the protrusions or ridges, a balance adjustment function for the fan can be provided.

  Furthermore, in the propeller fan of the present invention, in any one of the above-described propeller fans, serrations are formed on the outflow edge to the downstream side of the air flow of the notch portion provided in the downstream end edge of the ring. It is provided.

  According to the present invention, since the serration is provided at the outflow edge to the downstream side of the air flow of the notch provided in the downstream end edge of the ring, the air flow around the ring is on the downstream side of the ring. It is possible to break the two-dimensionality of the vortex generated when flowing out from the edge. As a result, it is possible to suppress the generation of sound of a specific frequency component due to the vortex generated when the air flow flows out from the downstream edge of the ring. Further, by finely adjusting the dimensions of the serrations, it is possible to provide a balance adjustment function for the fan.

According to the present invention, the rigidity against deformation of each blade in the direction of the rotation axis can be increased by the ring without increasing the thickness of the blade. In addition, since the ring is provided at a position on the inner peripheral side with respect to the outer peripheral edge of the blade, the ring suppresses the centripetal flow at the outer peripheral part of the blade, and as an auxiliary blade having an effect of suppressing the stall near the outer peripheral edge of the blade. It functions, and its rectifying effect can maintain and improve the basic performance of the propeller fan, such as the blowing performance, efficiency and noise performance, and at the same time, the ring circumference can be shortened. The weight can be reduced by making it as small as possible. In addition, since the remove the portion provided with the notches on the upstream edge and the lower stream side edge of the ring, it is possible to reduce the weight of the volume equivalent was deleted by notch, In addition, the notch at the upstream edge has a smooth convex curve at the portion corresponding to the front of the blade leading edge in the rotational direction, and has a negative stall suppression function at least near the outer periphery of the blade. The rise wall surface that is erected in the axial direction from the pressure surface has been deleted except for the auxiliary wing equivalent part that is provided so that the height increases smoothly from the front edge to the rear edge of the blade. Even if the upstream edge of the ring comes into contact with the ventilated target device due to an unforeseen event, the notch on the ring side will not be strongly caught by the ventilated target device. Contact with the equipment Auxiliary wings that can stop each other's damage lightly and have a stall suppression effect near the outer periphery of the blade against the ring provided mainly to increase the rigidity against deformation of the blade in the axial direction. This makes it possible to reduce the weight of the propeller fan by providing a notch in the ring, and the basics such as fan performance, efficiency and noise performance by making the ring act as an auxiliary wing. It is possible to simultaneously maintain and improve performance and increase rigidity against deformation in the rotation axis direction.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 4 .
FIG. 1 is a perspective view of the propeller fan 1 according to the first embodiment of the present invention, FIG. 2 is a front view thereof, and FIGS . 3 and 4 show a state in which the ring is unfolded. A side view is shown.
The propeller fan 1 is, for example, an injection-molded product made of polypropylene resin (PP) mixed with about 30 wt% of glass fiber. The propeller fan 1 includes a cylindrical hub 2 at the center and a plurality of pieces (in the illustrated example, on the outer periphery). Nine blades (blades) 3 are integrally formed radially.

  Each blade 3 includes a front edge 4 positioned on the rotation direction leading side in the circumferential direction, a rear edge 5 positioned on the rotation direction lagging side, and an outer peripheral edge connecting the front edge 4 and the rear edge 5 at the outermost peripheral position in the radial direction. 6 and a thin plate-shaped airfoil cross-sectional shape. Each blade 3 has a sickle shape in which the leading edge 4 is curved toward the rotational advance side as the radial direction outwards and the trailing edge 5 is slightly curved toward the rotational advance side as the radial direction outwards. . A serration 7 is provided on the rear edge 5.

Further, each blade 3 is integrally formed on the outer periphery of the cylindrical hub 2 with a predetermined inclination in the circumferential direction, and a constant blade height (in the axial direction) between the front edge 4 and the rear edge 5 In the case of the example, it is configured to have about 30 mm). When this blade 3 is rotated clockwise in FIGS. 1 and 2 (rotation direction N), the back side of the paper surface is the pressure surface (positive pressure surface) 8, the front side of the paper surface is the negative pressure surface 9, and air is introduced from the front side of the paper surface. It is designed to be ventilated in the reverse direction. 3 and 4 , the rotation direction N of the propeller fan 1 is indicated by an arrow, and the airflow is ventilated from the left side to the right side in FIGS . 3 and 4 .

The propeller fan 1 is provided with a ring 10 for increasing the strength for connecting a plurality of blades 3 to each other in order to prevent the blades 3 from being deformed in the rotation axis direction. This ring 10 has a configuration in which a part of a cylindrical ring whose axial width is equal to or slightly larger than the blade height is deleted by notches 12 and 14 as described later, and is integrated with each blade 3. Molded. Further, as shown in FIG. 2, the ring 10 is provided at dimensional positions from the outer peripheral edge 6 to 5 to 45 when the radial direction dimension from the root portion of each blade 3 to the outer peripheral edge 6 is 100. Yes.

  The installation position of the ring 10 excludes the outermost peripheral part of the blade 3 so as not to restrict the shape of the outermost peripheral part of the blade that is most efficient for the propeller fan 1, and the ring 10 is centripetal at the outer peripheral part of the blade. It functions as an auxiliary wing S that has the effect of suppressing the flow and suppressing stall in the vicinity of the blade outer peripheral edge 6, and can maintain and improve the basic performance such as the blowing performance, efficiency and noise performance of the propeller fan 1 by its rectifying effect, Moreover, it is set from the composite viewpoint that the effect of increasing the rigidity against the deformation of the blade 3 can be sufficiently secured. As described above, when the radial dimension of the blade 3 is 100, the outer peripheral edge is in the range of 5 to 45. It is installed at the dimension position.

  In order for the ring 10 to function as the auxiliary wing S as described above, the shaft 10 extends from the suction surface 9 of the blade 3 so as to be concentric with a bell mouth formed on a shroud (not shown) for guiding air to the propeller fan 1. It is essential to have a wall surface that is raised at a certain height in the direction. This rising wall is peeled off from the shroud surface and prevents any further air flow toward the center of the fan from going inward so that it is pushed axially downstream by the adjacent blade 3. The function as the auxiliary wing S is assumed. An example of the auxiliary wing S constituted by the rising wall surface is indicated by a hatched area S surrounded by a two-dot chain line in FIG.

  Although it is desirable that the height of the rising wall surface (auxiliary blade S) is higher, since a target device to be ventilated such as a radiator or a condenser is arranged on the upstream side of the propeller fan 1, preferably, Thus, the height is equal to or less than the height of the ring 10. Also, this rising wall surface starts from 0 to 20% cord position from the front edge 4 when the cord length from the leading edge 4 to the trailing edge 5 of the blade 3 is 100% cord, and smoothly rises to the trailing edge 5 Ideally, it should be provided so as to increase. This is because the static pressure on the surface of the blade 3 increases toward the trailing edge 5 side, and the turbulence of the flow is caused by the air flow separated from the shroud or the air flow flowing backward from the downstream side through the tip clearance of the blade 3 due to the pressure difference. Since there is a tendency to become stronger, it is preferable to secure the annular flow path by increasing the height of the wall surface toward the rear edge 5 side.

As shown in the reference example shown in FIG. 3, the ring 10 having the function as the auxiliary wing S has a notch between the trailing edges 5 of the blades 3 adjacent to each other on the downstream edge 11 in the ventilation direction. 12 is provided. This notch 12 is a pressure between the rear edge 5 of the blade 3 adjacent to each other and the front edge 4 of the blade 3 in the rotational direction from the rear area in the rotational direction to the rear edge 5 of the blade 3. It is provided so that substantially the entire area on the surface side is deleted. As a result, the ring 10 is reduced in weight by a considerable amount corresponding to the volume deleted at the notch 12. However, since the weight cannot be sufficiently reduced by this alone, the following configuration is adopted in order to further reduce the weight of the ring 10 while ensuring the function as the auxiliary wing S.

In the present embodiment, in addition to the notch 12 provided on the downstream edge 11 of the ring 10, the ring 10 is provided with a notch 14 on the upstream edge 13 of the ring 10. Yes. As shown in FIG. 4, the notch 14 is removed by removing a part of the ring 10 between the leading edges 4 of the blades 3 adjacent to each other, leaving at least a portion corresponding to the above-described auxiliary wing S. Is provided. In addition, the notch 14 provided on the upstream edge 13 of the ring 10 is arranged in front of the front edge 4 of the blade 3 in the rotational direction in consideration of safety when it comes into contact with a ventilation target device such as a radiator or a condenser. The part corresponding to is a smooth convex curve 14A.

With the configuration described above, according to the present embodiment, the following operational effects can be obtained.
When the propeller fan 1 is rotated in the N direction via a motor (not shown), the air flow that has passed through the ventilation target device such as a radiator or a condenser is guided to the propeller fan 1 by a shroud (not shown), and the pressure surface ( The air is ventilated from the front side to the back side through a blade 10 having a positive pressure surface 8 and a negative pressure surface 9.

  A thin plastic propeller fan 1 applied to an automobile engine radiator or a cooling fan for an air conditioning condenser is provided in an engine room, such as vibration, high temperature, water pressure caused by water splashed when traveling in a submerged channel, etc. to be influenced. These act on the propeller fan 1 as an external force for deforming the blade 3. On the other hand, by providing the ring 10 that couples a plurality of blades 3 to each other, the strength of each blade 3, particularly the rigidity against deformation in the direction of the rotation axis, is increased. Deformation can be prevented.

  Further, the ring 10 is provided at dimensional positions from the outer peripheral edge 6 to 5 to 45 excluding the outermost peripheral portion of the blade 3 when the radial direction dimension of the blade 3 is 100, and therefore the blower of the propeller fan 1 The ring 10 can be provided without particularly restricting the shape of the outermost peripheral portion of the blade that is most efficient for performance. As a result, the degree of freedom in designing the shape of the outermost peripheral part of the blade can be ensured, and the basic performance such as the blowing performance, efficiency and noise performance of the propeller fan 1 can be maintained.

  At the same time, the ring 10 forms a rising wall surface having a certain width in the axial direction from the suction surface of the blade 3, so that the ring 10 peels off from the shroud having a sharply changing cross-sectional shape and faces the center of the propeller fan 1. It also functions as an auxiliary wing S that suppresses the flow. The rectifying effect as the auxiliary blade S can suppress the centripetal flow generated at the outer periphery of the propeller fan 1 having a particularly small dimension in the depth direction, thereby suppressing the decrease in the effective radius in the propeller fan 1. As a result, it is possible to improve basic performance such as blowing performance, efficiency and noise performance.

  Further, since the ring 10 is provided at a position entering the radially inner peripheral side from the outer peripheral edge 6 of the blade 3 as described above, the peripheral length of the ring 10 is shorter than that provided on the outer peripheral edge 6. can do. Therefore, the volume of the ring 10 itself can be reduced as much as possible, and the weight of the propeller fan 1 can be reduced. In addition, since the notch 12 is provided on the downstream edge 11 of the ring 10 and a part of the notch 12 is deleted, the ring 10, that is, the propeller fan 1 is reduced in weight by the amount corresponding to the volume deleted by the notch 12. can do.

Further, as described above, by providing the notch portion 14 on the upstream edge 13 of the ring 10, the ring 10 is further reduced in weight by a considerable amount corresponding to the volume deleted by the notch portion 14. Will be. For this reason, the propeller fan 1 can be sufficiently reduced in weight. Further, the cutout portion 14 is deleted so as to leave a portion corresponding to the auxiliary wing S having a stall suppressing effect at least in the vicinity of the outer peripheral edge 6 of the blade 3, so that the function as the auxiliary wing S is maintained as it is. can do. Accordingly, it is possible to expect the effect of maintaining and improving the basic performance such as the air blowing performance, efficiency and noise performance of the fan by causing the ring 10 to function as the auxiliary blade S.

Further, when the cutout portion 14 is provided in the upstream end edge 13, the portion corresponding to the front side of the front edge 4 of the blade 3 in the rotational direction is a smooth convex curve 14A. Even if the upstream edge 13 of the ring 10 comes into contact with the ventilation target device, the notch 14 on the ring 10 side is not strongly caught by the ventilation target device. Therefore, the notch 14 can be provided in the upstream edge 13 of the ring 10 to reduce the weight of the propeller fan 1, and even if the propeller fan 1 and the ventilated target device come into contact with each other at the time of abnormality, they are mutually connected. Damage can be stopped.

  As described above, according to the present embodiment, without increasing the thickness of the blade 3, the rigidity of each blade 3 is increased while maintaining its thinness, and the propeller fan is prevented from being deformed in the axial direction. Thus, it is possible to realize the reduction in weight and the maintenance and improvement of basic performance such as air blowing performance, efficiency and noise performance.

[ Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The present embodiment is different from the first embodiment in the configuration of the notch 12A provided at the downstream end edge 11 of the ring 10. Since other points are the same as those in the first embodiment, description thereof will be omitted.
That is, in the first embodiment, the notch 12 extends from the rear area in the rotational direction of the line connecting the rear edge 5 of the blade 3 adjacent to each other and the front edge 4 of the blade 3 to the rear edge 5 of the blade 3. The entire area on the pressure surface side was deleted. However, in the present embodiment, the depth and size of the notch 12A provided in the downstream end edge 11 are determined according to the strength required of the blade 3 and the notch 12 of the first and second embodiments. It is comprised so that it may be made smaller.

  As shown in FIG. 5, the notch 12 </ b> A has a notch depth of the ring 10 on the pressure surface side between the rear edges 5 of the blades 3 adjacent to each other on the downstream edge 11 of the ring 10. Arbitrarily set according to the strength required of the blade 3 before and after the intermediate position of the axial width dimension, and a smooth concave curve is formed between the rear edge 5 on the front side in the rotational direction and the rear edge 5 on the rear side. , Configured to delete some of it. Further, in this embodiment, as shown in FIGS. 5A and 5B, protrusions or ridges 15 for randomly disturbing the flow around the ring are formed on the surface on the outer peripheral surface side of the ring 10 at a predetermined pitch. It is set as the structure shape | molded integrally by.

  According to the present embodiment, as described above, the notch portion 12A provided on the downstream end edge 11 of the ring 10 is connected to the rear edge 5 of the blade 3 adjacent to the front edge 4 of the blade 3. The entire area on the pressure surface side from the rear region in the rotation direction to the rear edge 5 of the blade 3 is maximized, and can be arbitrarily deleted within a range according to the strength required for the blade 3. For this reason, the range where the notch 12A is provided and the downstream end edge 11 of the ring 10 is deleted is the rearward direction in the rotational direction of the line connecting the rear edge 5 of the blade 3 and the front edge 4 of the blade 3 adjacent to each other. It is possible to set an appropriate range by maximizing the substantially entire area on the pressure surface side from the blade 3 to the rear edge 5 of the blade 3.

  That is, when priority is given to increasing the rigidity of the blade 3 against deformation, the notch 12A provided on the downstream end edge 11 of the ring 10 is shallow and small, giving priority to securing strength, and noting weight reduction. It is possible to give priority to weight reduction by increasing the portion 12A deeper and larger to increase the volume equivalent. Therefore, it is possible to increase the degree of freedom in selecting whether to give priority to securing strength or reducing weight according to the use environment or the like.

  In addition, since the protrusions or ridges 15 that disturb the flow are provided on the outer peripheral surface side of the ring 10, the air flow around the outer peripheral surface of the ring 10, which tends to be unstable, is randomly generated by the protrusions or ridges 15. Can be disturbed. As a result, it is possible to suppress the generation of sound of a specific frequency component due to an unstable air flow. Further, a support beam (not shown) of the drive motor is generally provided on the downstream side of this type of propeller fan 1, but the distance from the support beam is continuously changed by the protrusions or protrusions 15. The generation of periodic sounds can also be suppressed. Further, by finely adjusting the height of the protrusions or ridges 15, it is possible to provide a balance adjustment function for the fan.

[ Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
This embodiment differs from the first and second embodiments described above in that serrations are provided at the air outflow ends of the notches 12 and 12A provided at the downstream end edge 11 of the ring 10. . Since other points are the same as those in the first embodiment, description thereof will be omitted.
In this embodiment, as shown in FIGS. 6A, 6 </ b> B, and 6 </ b> C, a notch is formed with respect to the notches 12 and 12 </ b> A provided on the downstream end edge 11 of the ring 10. Sawtooth serrations 16A, 16B, and 16C are provided at the outflow edge to the downstream side of the air flow of 12 and 12A.

  The serrations 16A, 16B, and 16C described above correspond to the strength of the ring 10 corresponding to the noise of a specific frequency component to be suppressed or the rigidity of the blade 3 to be secured, and the height and width of the teeth of the serrations 16A, 16B, and 16C. The number and the like can be appropriately set as shown in FIGS. 6A, 6B, and 6C, for example.

  As described above, by providing the serrations 16A, 16B, and 16C on the outflow edge to the downstream side of the air flow of the notches 12 and 12A provided in the downstream end edge 11 of the ring 10, the ring 10 and the surroundings are provided. The two-dimensionality of vortices that are generated when the air flow flows out from the downstream edge 11 of the ring 10 can be broken. For this reason, generation | occurrence | production of the noise of specific frequency components, such as a periodic sound and an overall noise resulting from the vortex which arises when an air flow flows out from the downstream edge 11 of the ring 10, can be suppressed. Further, by finely adjusting the dimensions of the serrations 16A, 16B, and 16C, a balance adjustment function for the fan can be provided.

  In addition, this invention is not limited to the invention concerning the said embodiment, In the range which does not deviate from the summary, it can change suitably. For example, the number, shape, and configuration of the blades 3 are not limited to those of the above-described embodiment. For example, a blade that does not have the serration 7 may be used.

1 is a perspective view of a propeller fan according to a first embodiment of the present invention. It is a front view of the propeller fan shown in FIG. It is a side view of the state which developed a ring of a propeller fan concerning a reference example of the present invention . It is a side view of a developed state of the ring of the propeller fan shown in FIG. It is the side view (A) of the state which expand | deployed the ring of the propeller fan which concerns on 2nd Embodiment of this invention, and its aa arrow enlarged view (B). It is a side view of three examples (A), (B), and (C) from which the state of expand | deployed the ring of the propeller fan which concerns on 3rd Embodiment of this invention differs.

DESCRIPTION OF SYMBOLS 1 Propeller fan 2 Hub 3 Blade 4 Leading edge 5 Trailing edge 6 Outer peripheral edge 9 Suction surface 10 Ring 11 Downstream side edge 12, 12A Notch part 13 Upstream side edge 14 Notch part 14A Convex curve 15 Protrusion or protrusion 16A, 16B, 16C Serration N Rotation direction S Aileron

Claims (4)

In a resin propeller fan having a hub and a plurality of blades radially provided on the outer periphery of the hub,
A ring that couples the plurality of blades to each other at a position on the inner peripheral side of the outer peripheral edge of the blade;
The ring is removed by partially notch between the front edge each other and trailing edges cross the blades that are adjacent to each other of the upstream edge and the lower stream side edge of the ventilating direction,
The notched portion of the upstream edge provided on the suction surface side that is close to the ventilation target device to be ventilated by the propeller fan and is likely to be peeled off on the blade surface is the rotation of the blade leading edge. A portion corresponding to the front in the direction is a smooth convex curve, and at least a rising wall surface standing in the axial direction from a suction surface having a stall suppressing function near the outer peripheral edge of the blade, A propeller fan, wherein a part corresponding to an auxiliary wing provided so as to increase in height smoothly from the leading edge to the trailing edge is removed . The notch provided at the downstream edge of the ring reaches the trailing edge of the blade from the rearward direction in the rotational direction of the line connecting the trailing edge of the blade and the leading edge of the blade adjacent to each other. 2. The propeller fan according to claim 1 , wherein the propeller fan is deleted within a range corresponding to a strength required for the blade, with a substantially entire region on the pressure surface side between the first and second portions being maximized. On the outer peripheral surface of the ring, the propeller fan according to claim 1 or 2, characterized in that projections or ridges disturb the air flow is provided. The serration is provided in the outflow edge to the downstream of the air flow of the said notch provided in the said downstream edge of the said ring to the downstream, The Claim 1 thru | or 3 characterized by the above-mentioned. The described propeller fan.

Images