JP2007040197A - Propeller fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propeller fan capable of suppressing a centripetal stream and improving air blowing performance. <P>SOLUTION: A part where an air passage 6 of a shroud 2 surrounds the peripheral direction of a rotary vane wheel 3 becomes a circle, but a plate-like projection 4 in this invention is erected on the surface of a vane on the negative pressure side of the rotary vane wheel 3 which becomes a position on a concentric circle with the circle. Air peeld off from the surface of the shroud 2 due to the plate-like projection 4 is prevented from flowing an inner side more by the plate-like projection 4 and pushed into the downstream side in the axial direction of the rotary vane wheel 3 by the nearby vane. The plate-like projection 4 is erected by facing the axial direction of the rotary vane wheel 3 at an angle at which it becomes parallel with the internal wall of the part where the air passage 6 of the shroud 2 surrounds the peripheral direction of the rotary vane wheel 3 or more from the surface of the vane 8 on the negative pressure side. If a part from a vane front fringe to a vane rear fringe is 100% chord (100% vane chord length), it is ideal that the plate-like projection 4 is formed in such a way that the protrusion of the plate-like projection 4 starts at a position of 0 to 20% chord from the vane front fringe, and its height is smoothly increased up to the vane rear fringe. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a propeller fan, and more particularly to a propeller fan that promotes the ventilation action of an on-vehicle heat exchanger such as a radiator or a condenser.

  Resin-made propeller fans used as cooling fans for vehicle radiators and condensers for air conditioners may have a large dimension in the depth direction (thickness direction) on the assumption that they are installed in a narrow engine room. Can not. For this reason, the shroud cross-sectional shape from the rectangular radiator or the like to the circular fan inflow port changes sharply, and the rectifying effect is remarkably limited. In particular, the bell mouth portion provided at the fan inflow portion is often configured with a small radius angle R (chamfering). For this reason, most of the air that has passed through a rectangular radiator or the like tends to become a centripetal flow (centripetal flow) toward the center of the fan due to the inertial force, and the effective radius of the fan is reduced. Increases noise.

  In order to avoid the deterioration of the above performance etc., the bell mouth with the elliptical angle R and the bell mouth with the relatively large angle R constituting the main part of the bell mouth and only the part that interferes with the propeller fan is applied. (For example, Patent Document 1).

JP 2001-349300 A

  However, even the above-described technique has a side effect such that a sufficient effect cannot be obtained, or discrete frequency sound generated by the interaction between the rotor blade of the propeller fan and the shape of the shroud protrudes.

  Therefore, the present invention has been made in view of the above, and an object thereof is to provide a propeller fan that suppresses centripetal flow and improves air blowing performance without increasing the size in the depth direction.

  In order to achieve the above-described object, a propeller fan according to the present invention includes an axial flow type rotary impeller, and the shape of an air passage is changed from a substantially rectangular shape to a circular shape. A propeller fan having a shroud installed downstream of an in-vehicle heat exchanger, from the suction side blade surface of the rotary impeller at a position concentric with the circular shape of the air passage of the shroud, A plate-like protrusion that is erected in the axial direction of the rotary impeller at an angle that is parallel or tapered to the inner wall of the air passage at a portion surrounding the circumferential direction of the rotary impeller with a circular cross-sectional shape of the shroud It is made to have.

  In a propeller fan installed in a narrow place downstream of the on-board heat exchanger without taking a large dimension in the depth direction, where the cross-section changes from a rectangle to a circle, especially where the rectangle turns from a corner to a circle Thus, the air flowing along the relatively gentle slope of about 80 to 60 degrees with the axial direction of the axial flow type impeller is suddenly changed to the axial direction by the impeller. At this time, the air flowing on the gentle slope cannot be suddenly changed due to its inertial force and easily peels off. If it peels off, it will pass through the vicinity of the outer peripheral portion of the rotary impeller, which has the highest air blowing efficiency, and will be infiltrated into the portion near the inner periphery.

  In the present invention, a plate-like protrusion is erected from the surface of the suction side blade of the rotary impeller, which is positioned concentrically with the circular shape of the air passage, thereby separating the air from the shroud surface into a centripetal flow. Air that flows backward from the downstream through the wing clearance is prevented from flowing further inward. Further, such air is pushed in at a high speed by the adjacent blades downstream in the axial direction of the impeller. Therefore, since the air blowing action is actively performed in the annular air passage formed outside the plate-like protrusions of the wing, the air blowing efficiency is improved.

  In addition, since the plate-like protrusion is provided on the suction side blade surface of the rotary impeller that is concentric with the air passage, the air resistance of the protrusion when the impeller rotates is reduced, thereby reducing the shaft Since the air pushed out in the downstream direction also flows smoothly along the circumferential direction of the rotary impeller in one space blocked by the plate-like protrusion, the blowing efficiency is good. The plate-like projections surround the circumferential direction of the impeller and are erected in the axial direction with an angle parallel to or tapered with the inner wall of the air passage in the circular shape. This is because it is the minimum necessary angle to keep it from going further inward.

  The propeller fan according to the present invention is such that in the propeller fan, the plate-like protrusion starts to protrude from the blade leading edge 0 to 20% cord position, and the height smoothly increases to the blade trailing edge. is there.

  The static pressure on the surface of the blade increases as it goes to the trailing edge of the blade, and the tendency for air separating from the shroud as centripetal flow and air flowing back from the downstream through the tip clearance of the blade tip enters and becomes turbulent increases. Therefore, it is preferable to increase the plate-like protrusion toward the trailing edge of the blade to ensure an annular air passage. The reason why the height change is smooth is to prevent the air flow from being disturbed unnecessarily, and to cope with this because the mixing and diffusion of the air gradually changes toward the trailing edge.

  Further, in the propeller fan according to the present invention, in the propeller fan, the plate-like protrusion ranges from 5 to 45 from the blade outer edge when the length from the blade outer edge to the outer periphery of the hub is 100. It is intended to be erected.

  Since the peripheral speed of the impeller blade increases toward the outer edge, the efficiency of pushing air downstream is high. In the present invention, this highly efficient portion is used to push the air separated from the air passage of the shroud into a centripetal flow and the air returning from the gap between the shroud and the rotor wheel downstream from the high pressure portion downstream. Therefore, when the length from the outer periphery of the hub to the outer edge of the blade is 100, the plate-like protrusion is erected in a range from 5 to 45 from the outer edge of the blade.

  In the propeller fan according to the present invention, the height of the plate-like protrusion is not more than the height of the rotary impeller in the propeller fan.

  The higher the height of the plate-like protrusion, the more efficiently the centripetal flow that separates from the air passage and the air flow that flows backward from the downstream through the gap between the blade and the air passage are pushed efficiently. This is preferable in terms of securing an annular air passage. However, since a heat exchanger is usually arranged in the vicinity of the upstream of the rotary impeller, the rotary blade is used to secure a gap for the purpose of avoiding contact with the heat exchanger when foreign matter is mixed or deformed. It is preferable that the height is equal to or less than the height of the hub 7 of the vehicle 3.

  As described above, according to the propeller fan according to the present invention, the centripetal flow of air forcedly diffracted by the shroud and the rotary impeller is skillfully suppressed without increasing the dimension in the depth direction. The high efficiency part allows the air to flow backwards. Thereby, the ventilation efficiency of the whole propeller fan improves.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  FIG. 1 is a front view showing the entire propeller fan. The propeller fan 1 is roughly composed of an axial flow type impeller 3 and a shroud 2 that surrounds the shroud 2 and forms an air passage. In the rotary impeller 3, blades 8 (9 in the figure) radially attached to the hub 7 rotate clockwise about the axis 5 toward the paper surface, and work to push air out from the front of the paper surface.

  A heat exchanger such as a vehicle radiator or a condenser of an in-vehicle air conditioner is provided upstream of the shroud 2 (before the paper surface). The vehicular radiator is almost rectangular in structure. On the other hand, when the radiator is cooled by using an axial flow type impeller, the air passage must be circular. Therefore, the air passage formed by the shroud has a rectangular entrance (near the paper surface) and a circular exit, and the shape is changed from a rectangle to a circle in the vicinity of the entrance where the rotary impeller is disposed.

  The present invention is characterized in that the plate-like protrusion 4 is erected on the surface of the blade 8 on the negative pressure side (front side in FIG. 1) of the rotary impeller 3. More specifically, the portion where the air passage 6 of the shroud 2 surrounds the circumferential direction of the rotary impeller 3 is a circle, but the plate-like protrusion 4 of the present invention is a rotary vane that is positioned concentrically with the circle. It is erected on the wing surface on the negative pressure side of the vehicle 3.

  2 is a cross-sectional view taken along the line AA showing the cross-sectional shape of the propeller fan in FIG. As shown in the figure, in addition to the above, the plate-like protrusion 13 according to the present invention has the air passage 6 of the shroud 2 surrounding the circumferential direction of the rotary impeller 3 from the surface of the blade 8 on the negative pressure side. It is erected in the axial direction 10 of the rotary impeller 3 more than an angle parallel to the inner wall 11 of the part. In the case of this figure, it is the same as the axial direction 10 of the rotary impeller 3 with an angle parallel or tapered to the inner wall 11.

  FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1 showing a case where the plate-like protrusion is not oriented in the axial direction. As shown in this figure, the plate-like protrusion 17 is erected at an angle 18 parallel to the angle 16 of the inner wall of the air passage 15. Thus, the plate-like protrusion 17 may be at an angle 18 parallel to the angle 16 of the inner wall of the air passage 15, or even when the angle 16 of the inner wall of the air passage 15 is inclined, as in the case of FIG. The axial direction 10 of the rotary impeller 3 may be directed.

  In a propeller fan installed in a narrow place downstream of the on-board heat exchanger without taking a large dimension in the depth direction, where the cross-section changes from a rectangle to a circle, especially where the rectangle turns from a corner to a circle (9 in FIG. 1), it flows along a relatively gentle slope of about 80 to 60 degrees (see reference numeral 2 in FIG. 2 or reference numeral 2 in FIG. 3) with the axial direction of the axial-flow rotor wheel. The air is suddenly changed in the axial direction by the rotary impeller 3. At this time, the air flowing on the gentle slope cannot be suddenly changed due to its inertial force and easily peels off. If it peels off, the air becomes a centripetal flow, passes through the vicinity of the outer peripheral portion (annular flow path) with the highest blowing efficiency of the rotary impeller, enters the portion near the inner periphery, and lowers the blowing efficiency.

  As shown in FIG. 1, in the present invention, the plate-like protrusion 4 is erected from the surface of the suction side blade 8 of the rotary impeller 3 that is concentric with the circular shape of the air passage 6. The air separated from the surface of 2 is prevented from flowing further inward by the plate-like protrusions 4 and is pushed in the downstream in the axial direction of the rotary impeller 3 by the adjacent blade. Therefore, since the air blowing action in the annular air passage formed outside the plate-like protrusion 4 of the wing is actively performed, the air blowing efficiency is improved.

  Also, as shown in FIG. 2 or 3, the plate-like protrusions 13 and 17 are provided on the suction side blade surface of the rotary impeller that is concentric with the air passages 6 and 15, so that the impeller rotates. This reduces the air resistance of the projections, and the air pushed downstream in the axial direction also causes the circumferential direction of the rotary impeller 3 in one space blocked by the plate-like projections 13 and 17. Since it will flow smoothly along, air blowing efficiency is good. The plate-like projections 13 and 17 are provided so as to stand in the axial direction 10 at an angle that surrounds the circumferential direction of the rotary impeller 3 and is parallel or tapered with the inner wall 11 of the air passages 6 and 15 in the circular shape. The reason is that the angle is the minimum necessary to keep the air to be peeled away from going inward any further.

  FIG. 4 is an explanatory diagram showing an image of an annular air passage formed outside the plate-like protrusion. As shown in this figure, the annular air passage B formed outside the plate-like protrusions 4, 4a, 4b is a region where air can be pushed out most efficiently. Even if the plate-like protrusions 4, 4a, and 4b are erected on a circle at a position of 80% of the blade length, the work of sending out the air has an efficiency exceeding 50% of the entire rotary impeller. Therefore, according to the present invention, providing the plate-like protrusions 4, 4a, 4b is extremely useful because it leads to the maximum use of the annular air passage B.

  Returning to FIG. 2, in the annular air passage, the air flowing along the gentle slope that becomes the air passage of the shroud 2 suddenly changes direction, and the flow S <b> 1 that peels off and upstream The air flow S2 that flows backward from the downstream where the blade 8 and the air passage 12 flow from the downstream where the static pressure is relatively high flows into the surface of the blade 8 on the negative pressure side. 13, there is no further inside of the blade 8, and it is efficiently pushed downstream by the rotating blade 8. In order to ensure this action, the plate-like protrusion 13 is preferably erected in the axial direction, but when the air passage 15 has a tapered conical shape as in the case of FIG. Since the rate of air separation due to a sudden change in the path decreases, the plate-like protrusion 17 may be provided inclined at an angle parallel to the air passage 15 as shown in FIG.

  The higher the height h2 of the plate-like protrusion 13 is, the higher the air flow S1 that is separated and the air flow S2 from the downstream that flows backward through the gap between the blade 8 and the air passage 12. This is preferable in terms of securing an annular air passage that is efficiently pushed downstream. However, since a heat exchanger is usually disposed in the vicinity of the upstream of the rotary impeller 3, for safety, the height of the hub 7 of the rotary impeller 3 should be kept below. Good.

  FIG. 5 is a front view of the blade showing the length of the plate-like protrusion on the surface of the blade of the rotary impeller. Assuming that the blade leading edge 23 to the blade trailing edge 24 are 100% cords (100% chord length), the plate-like protrusion 4 is positioned from the position of 0 to 20% cord from the blade leading edge 23 (between reference numerals 22 to 21). Ideally, the protrusion starts and the height increases smoothly to the blade trailing edge 24. The static pressure on the surface of the blade increases as it goes to the blade trailing edge 24, and air that peels from the shroud or air that flows backward from the downstream through the tip clearance of the blade tip enters and becomes more prone to disturbance. Therefore, it is preferable to increase the plate-like protrusion 4 toward the blade trailing edge to ensure an annular air passage. The reason why the height change is smooth is to prevent the air flow from being disturbed unnecessarily, and to cope with this because the mixed diffusion of the air gradually spreads toward the trailing edge.

  FIG. 6 is a blade front view showing the span direction position of the plate-like protrusion on the surface of the blade of the rotary impeller. The plate-like protrusion 4 is preferably erected in a range from 5R to 45R from the blade outer edge 26 when the length from the outer periphery 25 of the hub 7 of the rotary impeller 3 to the blade outer edge 26 is 100R. As described above, since the peripheral speed of the wing 8 increases as the outer edge increases, work capable of efficiently extruding air becomes possible. Therefore, it is advantageous to provide the plate-like protrusions 4 in a region at least 5R or more and 50R or less, preferably 45R or less from the outer edge. This is because if the plate-like protrusion 4 is provided on the inner side than this, the efficiency of pushing in air starts to extremely decrease.

  As described above, the propeller fan according to the present invention is useful for the manufacture and use of a propeller fan having a shroud that is disposed downstream of an in-vehicle heat exchanger and whose depth dimension is greatly limited.

It is a front view which shows the whole propeller fan. It is AA sectional drawing which shows the cross-sectional shape of the propeller fan of FIG. It is AA sectional drawing of FIG. 1 which shows the case where a plate-shaped protrusion is not suitable for the axial direction. It is explanatory drawing which shows the image of the annular air path formed outside a plate-shaped protrusion. It is a wing | blade front view which shows the length of the plate-shaped protrusion in the surface of the blade | wing of a rotary impeller. It is a wing | blade front view which shows the span direction position of the plate-shaped protrusion in the surface of the blade | wing of a rotary impeller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Propeller fan 2 Shroud 3 Rotary impeller 4, 10, 13, 17 Plate-like protrusion 6, 12, 15 Air passage 7 Hub 8 Blade 11 Inner wall 23 Blade front edge 24 Blade rear edge 25 Hub outer periphery 26 Blade outer edge

Claims (4)

An axial-flow rotary impeller,
The shape of the air passage is changed from a substantially rectangular shape to a circular shape, the rotary impeller is provided in the circular shape portion, and a shroud installed downstream of the in-vehicle heat exchanger;
In a propeller fan having
Parallel to or taper from the inner wall of the air passage at a portion surrounding the circumferential direction of the rotary impeller of the shroud from the suction side blade surface of the rotary impeller at a position concentric with the circular shape of the air passage of the shroud A propeller fan characterized by having a plate-like protrusion standing upright in the axial direction of the rotary impeller at an angle of   2. The propeller fan according to claim 1, wherein the plate-like protrusion starts to protrude from a blade leading edge 0 to 20% cord position and smoothly increases in height to the blade trailing edge.   2. The plate-like protrusion is erected in a range from 5 to 45 from the outer edge of the blade, where the length from the outer edge of the rotor blade to the outer periphery of the hub is 100. 5. 2. The propeller fan according to 2.   The propeller fan according to any one of claims 1 to 3, wherein a height of the plate-like protrusion is not more than a hub height of the rotary impeller.

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