JP2008019769A - Centrifugal fan and blower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a centrifugal fan easily manufactured and reducing noises. <P>SOLUTION: In the centrifugal fan F of the present invention, blade units U composed of many annularly erected blades 2, and annular straightening rings 3 connecting the upper parts of many blades 2, are connected in multiple stages in the direction of the center shaft of the blade units U, and a disk-like base 1 having raised center is connected to the lower part of the blade unit U in the lowermost stage. The inside diameters of the multistage blade units U are reduced gradually in each stage as approaching the base 1. Straightening rings 3 in each of stages are not overlapped when viewed from a center shaft direction, and the outside diameter of the base 1 is set smaller than the inside diameter of the straightening ring 3 having the smallest diameter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a centrifugal fan in which a plurality of fins are arranged around a cylindrical shape, and a blower using the centrifugal fan.

The following [Patent Document 1] describes a blower (blower fan) using a centrifugal fan in which a plurality of blades are erected in an annular shape. Such a blower (centrifugal fan) is compact and has a large air volume, but has a large wind noise passing through the ventilation path, and further noise reduction is desired. For example, such a blower is used for a vehicle air conditioner or the like, or a noise reduction in a passenger compartment has recently progressed, and such a blower is required to be further improved in noise reduction. Therefore, as described in [Patent Document 2] below, a plurality of blades divided by a partition in the middle of the centrifugal fan in the axial direction is also known. This is because the drift or oscillating flow in the blower is considered to generate noise, so that the space is subdivided by a partition, and the flow is made uniform and steady to reduce noise.
JP-A-5-106591 Japanese Patent Laying-Open No. 2005-307928

  However, the centrifugal fan as described in [Patent Document 2] has a complicated structure and cannot be constructed unless a plurality of parts are assembled. In particular, when a centrifugal fan is to be molded by injection molding, it cannot be manufactured by a single injection molding, and improvement is desired. Further, as a blower, there is a demand for noise reduction by further suppressing noise generation at the tongue. Accordingly, an object of the present invention is to provide a centrifugal fan that is easy to manufacture and can achieve low noise. Another object of the present invention is to provide a blower capable of facilitating the manufacture of a centrifugal fan and further reducing noise.

  The centrifugal fan according to the present invention is a multi-stage coupling of blade units composed of a large number of blades standing in an annular shape and a ring-shaped rectifying ring connecting the upper portions of the blades in the central axis direction of the blade units. The lower part of the wing unit at the bottom stage is joined to a disk-like substrate with a raised center, and the inner diameter of the multi-stage wing unit is gradually reduced for each stage as it approaches the board, When viewed from the central axis direction, the rectifying rings for each stage are not overlapped, and the outer diameter of the substrate is smaller than the inner diameter of the rectifying ring having the smallest diameter.

  Further, the blower of the present invention has the above-described centrifugal fan housed in a case, and the case is a bell mouth that is opened in the central axis direction of the centrifugal fan and serves as a suction port for sucking air into the centrifugal fan. And a discharge port that is formed in the circumferential tangential direction of the centrifugal fan and discharges air, and that the inner inner wall connected to the discharge port of the case is formed in a multi-stage shape according to the multi-stage shape of the centrifugal fan. It is a feature.

  According to the centrifugal fan of the present invention, the length of the wing in the central axis direction is subdivided, and each stage of the wing unit is partitioned by a rectifying ring, so that the flow of wind sent from the inside of the centrifugal fan to the outside is reduced. By suppressing bias and swing, the flow can be made uniform and steady, and further noise reduction can be achieved. The centrifugal fan of the present invention is arranged so that the rectifying ring and the substrate of each blade unit do not overlap each other when viewed from the central axis direction. For this reason, the centrifugal fan of the present invention can be molded by a single injection molding by a resin injection molding method. At this time, the pair of injection molds are opened in the direction of the central axis of the centrifugal fan, and the upper and lower surfaces of each rectifying ring serve as parting portions of the mold.

  Further, according to the blower of the present invention, since the above-described centrifugal fan is used, further noise reduction can be realized, and the manufacture of the centrifugal fan is facilitated by facilitating the manufacture of the centrifugal fan. Furthermore, when viewed as the whole blower, the inner wall of the case, which is the tongue of the blower (the inner wall of the discharge port: which will be described in detail in the embodiment), is formed in a staircase shape that matches the staircase shape of the centrifugal fan. Thus, further noise reduction can be achieved not only with the centrifugal fan alone but also with the entire blower.

  Hereinafter, an embodiment of a centrifugal fan of the present invention and a blower using the centrifugal fan will be described with reference to FIGS. The blower B of this embodiment is used by being incorporated in a vehicle air conditioning unit. The blower B includes a centrifugal fan F inside the case C. The centrifugal fan F is rotatably attached to the case C via a motor M (see FIG. 1).

  The centrifugal fan F will be described. The centrifugal fan F includes a blade unit U that is stacked in a multi-stage shape, and a circular substrate 1 that is coupled to the lower end of the lowermost blade unit U and has a raised portion at the center. Each blade unit U is composed of a large number of blades 2 erected in an annular shape and an annular rectifying ring 3 that joins the upper portions of the large number of blades 2. As the multi-stage blade unit U approaches the substrate 1, the inner diameter (the inner diameter that serves as a reference for each stage. For example, the minimum inner diameter or the maximum inner diameter, or the average value of the inner and outer diameters of the rectifying ring 3). It is formed to be smaller.

  As shown in FIG. 3, the blades 2 are evenly arranged radially with respect to the central axis of the fan F. The blade 2 has a curved blade section, and the blade thickness is reduced toward the outer periphery of the fan F. An annular rectifying ring 3 is coupled to the outer side of the upper end of each blade 2. Each blade 2 is configured not to protrude outward from the outermost peripheral end of the rectifying ring 3. That is, in each wing unit U, the outer edge of the wing 2 coincides with the outer peripheral edge of the rectifying ring 3 or is located on the inner side thereof (in the present embodiment, it coincides). The lower end inside of each wing 2 is coupled to the rectifying ring 3 of the wing unit U one stage below. However, the lower end of the lowermost blade unit U is coupled to the substrate 1.

  As shown in FIG. 3, the wing 2 is shifted from the wings of other adjacent wing units U. In other words, the blade 2 of the uppermost blade unit U is shifted in position from the blade 2 of the middle blade unit U. Further, the blade 2 of the middle blade unit U is shifted in position from the blade 2 of the uppermost blade unit U and the lowermost blade unit U. If the position of the blades 2 is shifted in this way, the deviation and fluctuation of the flow of the wind sent from the inside of the centrifugal fan to the outside can be suppressed, the flow can be made uniform and steady, and the noise can be reduced. Will be realized. Here, the centrifugal fan F is divided into a plurality of parts in the direction of the rotation axis (in this embodiment, it is divided by the rectifying ring 3), and the space is subdivided to suppress uneven flow and oscillating flow to make the flow uniform and steady. This is used in combination with noise reduction to achieve further noise reduction.

  The rectifying ring 3 is curved so that the outer peripheral side is horizontal and the inner peripheral side faces upward. The substrate 1 has a spherical bulge at the center, and a mounting hole 4 for the output shaft of the motor M is formed at the center (corresponding to the rotating shaft of the centrifugal fan F). As shown in FIG. 3, when viewed from the direction of the rotation axis of the centrifugal fan F, the three rectifying rings 3 do not overlap. That is, the outer diameter of the middle rectifying ring 3 is smaller than the inner diameter of the uppermost rectifying ring 3. Similarly, the outer diameter of the lowermost rectifying ring 3 is smaller than the inner diameter of the middle rectifying ring 3. Furthermore, the outer diameter of the substrate 1 is smaller than the inner diameter of the lowermost rectifying ring 3.

  For this reason, the centrifugal fan F can be manufactured by a single resin injection molding. At this time, an undercut or the like does not occur in the molding die, and the die can be simply divided into two. The mold opening direction coincides with the rotational axis direction of the centrifugal fan F to be molded. At this time, the divided surfaces of the molds are located at the positions indicated by the one-point difference lines in FIG. As described above, since the three rectifying rings 3 do not overlap when viewed from the direction of the rotation axis of the centrifugal fan F, the pair of molds can be opened without any problem, and the manufacture is facilitated.

  Here, the upper and lower sides are defined with reference to FIG. 1 and FIG. 2, but the installation state of the centrifugal fan F is not limited to the state of FIG. 1 or FIG. For example, you may install so that the rotating shaft of the centrifugal fan F may become horizontal.

  The case C that houses the centrifugal fan F described above is basically in a cylindrical shape. However, the discharge port 5 is formed so as to extend in the tangential direction from the circumferential surface of the cylinder. A bell mouth 6 serving as a suction port is opened in one of the surfaces perpendicular to the central axis of the cylinder. As shown in FIGS. 1 and 2, the opening edge of the bell mouth 6 is curved toward the inside of the case C, and the suction flow is smoothly set inside the centrifugal fan F. The opening edge of the bell mouth 6 comes to be lower than the upper end of the centrifugal fan F attached to the inside of the case C.

  Further, the tongue portion 7 of the case C, that is, the inner wall portion of the discharge port 5 is formed in a multistage shape in accordance with the multistage shape of the centrifugal fan F described above. The inner wall portion is not a wall portion extending in the tangential direction from the outer peripheral surface of the cylinder, but a wall portion on the side where the curvature is changed from convex to concave. By doing in this way, the clearance gap between the centrifugal fan F and the inner surface of the tongue part 7 becomes substantially uniform. As a result, the deviation and fluctuation of the flow of the wind sent from the inside of the centrifugal fan to the outside are suppressed, the flow can be made uniform and steady, and the noise can be reduced. As described above, further noise reduction can be realized by using in combination with noise reduction by shifting the position of the blade 2 at each stage. The tongue 7 is considered to be a place where noise is likely to occur, and countermeasures at this place are effective.

  The centrifugal fan F and the blower B of the present invention are not limited to the embodiment described above. For example, in the above-described embodiment, each blade 2 is formed parallel to the rotation axis of the centrifugal fan F. This may be formed so that all the blades have the same inclination angle with respect to the rotation axis of the centrifugal fan, that is, so-called skew. In this case, at the time of forming the centrifugal fan, the pair of molds are opened while being rotated according to the inclination angle. By skewing, it is possible to further reduce the noise with the same air volume, or to further increase the air volume with the same noise.

It is a perspective view of one embodiment of a blower (centrifugal fan) of the present invention. It is sectional drawing of one Embodiment of the air blower (centrifugal fan) of this invention. It is a top view of one embodiment of a centrifugal fan of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Wing 3 Rectification ring 4 Mounting hole 5 Discharge port 6 Bell mouth 7 Tongue B Blower C Case F Fan M Motor U Blade unit

Claims (3)

A wing unit (U) comprising a plurality of wings (2) erected in an annular shape and an annular rectifying ring (1) that joins the upper portions of the wings (2) is formed of the wing unit (U). A centrifugal fan (F) in which a disk-shaped substrate (1) whose center is raised is coupled to the lower part of the lowermost blade unit (U) in a multi-stage manner in the central axis direction,
The inner diameter of the multistage blade unit (U) is gradually reduced in diameter for each stage as it approaches the substrate (1),
When viewed from the central axis direction, the rectifying rings (3) of each stage are not overlapped, and the outer diameter of the substrate (1) is made smaller than the inner diameter of the rectifying ring (3) having the smallest diameter. Centrifugal fan characterized by   The plurality of blades (2) in the blade unit (U) are arranged so as to be shifted from the blades (2) in the other adjacent blade units (U). The described centrifugal fan. A blower (B) in which the centrifugal fan (F) according to claim 1 is housed in a case (C),
The case (C) includes a bell mouth (6) that is opened in the central axis direction of the centrifugal fan (F) and serves as a suction port for sucking air into the centrifugal fan (F), and the centrifugal fan ( F) and a discharge port (5) that is formed toward the circumferential tangential direction and discharges air.
A blower characterized in that an inner inner wall (7) connected to the discharge port (5) of the case (C) is formed in a multistage shape in accordance with the multistage shape of the centrifugal fan (F).

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