JP2006258107A - Axial blower - Google Patents

Abstract

An axial flow blower that can keep the load on an electric motor low even when the rotational speed is increased to increase the amount of blown air.
In an axial blower in which a plurality of blades are integrally formed around a hub, a corner portion where a blade trailing edge and a blade outer peripheral portion that are in contact with a rotating air outflow portion intersect in an air outflow direction. A bulging portion that bulges in a convex shape is formed, and when the radius from the center of the rotating shaft to the outermost periphery of the blade is R, the bulging portion is formed in a range of 0.6R to R, and The trailing edge of the blade that extends from the exit portion in the direction of the rotation axis is curved in the direction in which the wind flows, and the center of the rotation shaft is defined as O. The outer periphery of the leading edge of the blade that is derived from Km, the center O, and is in contact with the tip (T) of the bulging part, and is derived from Kn, the center O and hits the rotating air inflow part. The line segment in contact with the end (S) is defined as Kf, the central angle between the line segment Km and the line segment Kn is α1, and the center between the line segment Kn and the line segment Kf. The case of the [alpha] 2, characterized in that the α1 = 0.05 × α2~0.15 × α2.
[Selection] Figure 1

Description

  The present invention relates to an axial blower used for an outdoor unit or the like of an air conditioner.

  As this type of axial blower, a configuration shown in FIGS. 13 and 14 is known. Among these, in the axial flow fan 10A shown in FIG. 13, the hub 11 and the plurality of blades 12 (only one is shown here) are integrally formed. As this axial blower 10A rotates in the direction of arrow X, the blade trailing edge 21 that hits the air outflow portion of the blade 12 was formed in a substantially straight line. Therefore, when increasing the air volume, the motor that drives the blower There has been a problem that the load increases and the blowing sound increases.

  On the other hand, the blade trailing edge portion 21 of the axial blower 10B shown in FIG. 14 is curved in a substantially arc shape, and a corner portion where the blade trailing edge portion 21 and the blade outer peripheral portion 22 intersect is bulged in a convex shape. It is the exit 23. However, since the range in which the bulging portion 23 is formed exists in a wide region exceeding 0.5r, where r is the radius from the center O of the rotating shaft to the blade outer peripheral portion 22, When the rotational speed is increased to increase the air volume, there is a problem that the flow loss at the blade trailing edge portion 21 increases, the load on the blower driving motor increases, and the blowing sound increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an axial blower that can keep the load on the motor low even when the rotational speed is increased to increase the amount of air flow. In offer.

  Another object of the present invention is to provide an axial blower capable of suppressing vortices generated at the blade trailing edge and suppressing an increase in blowing noise.

  Another object of the present invention is to provide an axial blower excellent in formability and cost reduction.

The invention according to claim 1 is an axial blower in which a plurality of blades are integrally formed around a hub.
From the center of the rotating shaft to the outermost periphery of the wing, it forms a bulge that bulges in the air outflow direction at the corner where the blade trailing edge that hits the rotating air outflow portion and the blade outer periphery intersect When the radius of R is R, the bulging portion is formed in the range of 0.6R to R,
The blade trailing edge that continues from the bulge to the rotational axis is curved in the direction in which the wind flows,
The center of the rotation axis is defined as O, the line segment derived from the center O and contacting the bay depth (Q) of the trailing edge of the blade is derived from Km, the center O and the tip of the bulging portion (T ) Is a line segment that comes into contact with the outer peripheral edge (S) of the blade leading edge that is derived from the center O and hits the rotating air inflow portion, and Kf is a line segment that comes into contact with the rotating air inflow portion. When the central angle between them is α1, and the central angle between the line segment Kn and the line segment Kf is α2, α1 = 0.05 × α2 to 0.15 × α2.

  The invention according to claim 2 is characterized in that when the arc length of the outer peripheral edge of one wing is CL, the arc length of the curved portion of the wing trailing edge is in a range of 0.4 to 0.6 CL. To do.

  In the invention according to claim 3, the starting point of the radially inner curved portion of the blade trailing edge is defined as U, and is derived from the center O of the rotating shaft and is in contact with the bay inner portion (Q) of the blade trailing edge. The length of the leg of the perpendicular line dropped from the point U to the line segment Km is L1, and the length of the leg of the perpendicular line lowered from the tip (T) of the bulging portion to the line segment Km is L2. L2 = 0.5 × L1 to 0.7 × L1.

  As is apparent from the above description, according to the present invention, an axial blower capable of keeping the load on the motor low can be obtained even when the rotational speed is increased to increase the amount of blown air.

  Hereinafter, the present invention will be described in detail based on preferred embodiments shown in the drawings. FIG. 1 is a plan view showing an overall configuration of an axial blower according to the present invention as viewed in the axial direction. In the axial blower 1, a hub 11 and three blades 12 are integrally formed and rotate in the direction of arrow X. FIG. 2 is an enlarged view of one blade 12 of the axial blower 1 shown in FIG. 1, and a blade trailing edge portion 21 corresponding to an air outflow portion of the blade 12 rotating in the arrow X direction, and a blade outer peripheral portion 22. The bulging portion 23 is formed by bulging a portion where the crosses with the projection in the direction in which the air flows. In this case, when the radius from the center O of the rotating shaft to the blade outer peripheral portion R is R, the bulge portion 23 is formed in the range from 0.6R to R in the blade trailing edge portion 21. Has been.

   FIG. 3 is a diagram showing the relationship between the formation range of the bulging portion 23, the air flow rate and the input of the electric motor. The bulging portion 23 is in the range from 0.6 R to R in the blade trailing edge portion 21. By forming, the flow loss near the blade trailing edge 21 can be suppressed, and the load applied to the electric motor can be reduced. Therefore, since the load applied to the electric motor can be reduced while increasing the air flow rate by increasing the peripheral speed of the blade outer peripheral portion 22, the energy saving performance of the air conditioner or the like can be improved.

  FIG. 4 is for explaining the outline shape of the blade trailing edge portion 21 and the bulging portion 23 shown in FIG. 2. First, the bulging portion 23 is connected to the blade outer peripheral portion 22 and is relatively large radially outward. An arc 31 that enters inward with a radius of curvature, an arc 32 that is convex in the direction of air outflow with the smallest radius of curvature, and an arc 33 that is concave in the direction of air outflow with a radius of curvature larger than the arc 32 are sequentially formed. It has a continuous shape. Further, the blade trailing edge portion 21 radially inward of the bulging portion 23 has a relatively large radius of curvature, and has an arc 34 that is concave in the air outflow direction, and an air outflow with a radius of curvature smaller than the arc 34. It has a shape in which a circular arc 35 having a concave shape in the direction is connected in order.

  In this way, by forming the bulging portion 23 into a shape in which three or more different arcs are connected, generation of vortices can be suppressed and noise can be reduced. Further, by forming the radially inner portion of the bulging portion 23 into a shape in which two arcs are connected, the blade area can be increased compared to the case where the arcs are formed by one arc, and the amount of blown air is increased. be able to.

  FIG. 5 shows the relationship between the arc length CL of the blade outer peripheral portion 22 of the blade 12 and the arc length LW of the curved portion of the blade trailing edge portion 21. It is set to be in the range of 0.4 CL to 0.6 CL.

  FIG. 6 is a diagram showing the relationship between the ratio of the curved portion LW to the arc length CL, the air flow rate, and the motor input. The arc length LW of the curved portion is in the range of 40% to 60% with respect to the arc length CL. By setting, the load applied to the electric motor can be suppressed to a small value while ensuring a constant air flow rate.

  FIG. 7 is a diagram for explaining the proportion of the bulging portion 23 occupied in the circumferential direction of the wing 12, where the center of the rotation axis is O, and the bay depth portion Q of the wing trailing edge 21 is derived from this center O. The line segment in contact is derived from Km, the center O and the line segment in contact with the tip T of the bulging portion 23 is derived from Kn, the center O, and the outer peripheral edge S of the leading edge of the blade impinging on the rotating air inflow portion. When the line segment in contact with the line segment is Kf, the central angle between the line segment Km and the line segment Kn is α1, and the central angle between the line segment Kn and the line segment Kf is α2, α1 = 0.05 × It shows that α2 to 0.15 × α2.

  FIG. 8 is a diagram showing the relationship between α1 / α2 and the amount of blown air and the motor input. Even when the number of rotations of the blower is increased to increase the amount of blown air, the motor is not increased without increasing the blowing noise. It is possible to reduce the load applied to the battery.

  FIG. 9 shows a radially outward portion of the curved portion of the blade trailing edge 21 and a protruding state of the radially inner portion in the wind outflow direction. The starting point of the radially inner curved portion of the blade trailing edge 21 is shown in FIG. Is U, and the line segment that is derived from the center O of the rotating shaft and contacts the bay depth Q of the wing trailing edge 21 is Km, and the length of the leg of the perpendicular line from the point U to the line segment Km is L1. When the length of the leg of the perpendicular line dropped from the distal end T of the bulging portion 23 to the line segment Km is L2, L2 = 0.5 × L1 to 0.7 × L1 is set.

  According to this configuration, as is clear from the relationship between the ratio of L2 to L1 shown in FIG. 10, the air flow rate, and the motor input, the load applied to the motor can be kept small without reducing the air flow rate.

  FIG. 11 shows the relationship between the arc length of the blade outer peripheral portion 22 of the wing 12 and the arc length in the circumferential direction of the portion corresponding to the back of the bay of the wing trailing edge portion 21. The radius of the outer periphery is R, and the arc length of the outer periphery is CL, and the arc from the center of rotation to the blade trailing edge corresponding to the air outflow portion from the blade leading edge corresponding to the air inflow portion out of the arc having a radius of 0.6 × R. When the arc length is Ye, Ye = 0.4CL to 0.6CL is set.

  FIG. 12 is a diagram showing the relationship between the ratio of the arc length Ye from the blade leading edge to the blade trailing edge with respect to the arc length CL of the outer periphery, the noise value, and the motor input. As is apparent from this diagram. The load on the motor can be kept small without increasing the blowing noise.

The top view seen in the axial direction which showed the whole structure of the axial blower which concerns on this invention. The figure which expanded and showed one wing | blade of the axial-flow fan 1 shown in FIG. The diagram which shows the relationship between the formation range of a bulging part, the ventilation volume, and the input of an electric motor. The figure for demonstrating the outline shape of the wing | wing trailing edge part and bulging part which were shown in FIG. The top view which shows the relationship between the arc length of a blade outer peripheral part, and the arc length of a blade trailing edge 2 curved part. The diagram which showed the relationship between arc length, ventilation volume, and motor input. The figure for demonstrating the ratio which a bulging part occupies for the circumferential direction of a wing | blade. The diagram which shows the relationship between the ratio which a bulging part occupies to the circumferential direction of a wing | blade, ventilation volume, and an electric motor input. The figure which showed the protrusion state to the wind outflow direction of the radial direction outer side part and radial direction inner side part of the curved part of a blade trailing edge part. The diagram which showed the relationship between the ratio of the radial direction outer side site | part shown in FIG. 9, and the protrusion part of a wind outflow direction, ventilation volume, and an electric motor input. The figure showing the relationship between the arc length of a wing | blade outer peripheral part and the arc length of the circumferential direction of the site | part corresponding to the bay depth part of a wing | wing trailing edge part. The diagram which showed the relationship between the ratio of the circular arc length from a blade front edge part to a blade rear edge part with respect to the circular arc length of an outer periphery, a noise value, and an electric motor input. The top view seen from the axial direction in order to show the structure of the conventional axial blower. The top view seen from the axial direction in order to show other composition of the conventional axial blower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial flow fan 11 Hub 12 Wing | blade 21 Wing | blade trailing edge part 22 Wing | blade outer peripheral part 23 The swelling part 31-34 Arc

Claims (3)

In the axial blower formed by integrally forming a plurality of blades around the hub,
From the center of the rotating shaft to the outermost periphery of the wing, it forms a bulge that bulges in the air outflow direction at the corner where the blade trailing edge that hits the rotating air outflow portion and the blade outer periphery intersect When the radius of R is R, the bulging portion is formed in the range of 0.6R to R,
The blade trailing edge that continues from the bulge to the rotational axis is curved in the direction in which the wind flows,
The center of the rotation axis is defined as O, the line segment derived from the center O and contacting the bay depth (Q) of the trailing edge of the blade is derived from Km, the center O and the tip of the bulging portion (T ) Is a line segment that comes into contact with the outer peripheral edge (S) of the blade leading edge that is derived from the center O and hits the rotating air inflow portion, and Kf is a line segment that comes into contact with the rotating air inflow portion. An axial blower characterized in that α1 = 0.05 × α2 to 0.15 × α2 where α1 is the central angle between them and α2 is the central angle between the line Kn and the line Kf.   The shaft according to claim 1, wherein when the arc length of the outer peripheral edge of one blade is CL, the arc length of the curved portion of the trailing edge of the blade is in a range of 0.4 to 0.6CL. Current blower.   The starting point of the curved portion radially inward of the blade trailing edge is set as U, the line segment derived from the center O of the rotating shaft and in contact with the bay depth (Q) of the blade trailing edge is set as Km, and the point U L2 is the length of the leg of the perpendicular line that is lowered to the line segment Km from L1 and L2 is the length of the leg of the perpendicular line that is lowered from the tip (T) of the bulging part to the line segment Km. The axial blower according to claim 1, wherein the axial flow blower is 5 x L1 to 0.7 x L1.

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