JP4726506B2 - Centrifugal multi-blade fan - Google Patents

Description

  The present invention relates to a centrifugal multiblade fan, and more particularly to a centrifugal multiblade fan having an improved blade portion and suitable for a vehicle air conditioner or the like.

  Conventionally, the performance of a blower related to the air blowing capacity and noise is greatly influenced by the fan blade shape, the scroll shape of the casing, and the like, and it is necessary to sufficiently consider them in designing.

  In the centrifugal multiblade fan, the length of each blade in the air flow direction is formed to be relatively short, so that an air flow along the blade is difficult to form, and vortices are likely to occur due to separation of the air flow. The vortex noise due to the separation is the main noise in the centrifugal multiblade fan. As a proposal to reduce such noise, for example, a proposal of an airfoil fan that reduces vortex noise due to separation of airflow from a blade by making the cross-sectional area of the blade into a blade shape has been made (for example, Patent Document 1).

  However, in the proposal as in the above-mentioned Patent Document 1, the air flow is biased from the suction surface of the blade to the pressure surface side of another blade adjacent to the operating point of the low pressure loss. There is a risk that shear flow may occur in the wake. In order to solve such a problem, a method of forcibly preventing the air flow bias by narrowing the interval between the radially outer ends of the blades can be considered. Since the relative speed increases at the end, the pressure recovery becomes insufficient, so that the blowing performance and noise characteristics may be deteriorated at the operating point of high pressure loss.

  In order to solve the above problems, the applicant has already made a proposal as shown in FIG. 7 (Patent Document 2). In FIG. 7, reference numeral 100 denotes a main blade. A plurality of main blades 100 are arranged in the circumferential direction around the rotation axis. An auxiliary blade group configured by the auxiliary blade 101 is provided on the radially outer side of the main blade group configured by the main blade 100. The auxiliary blade 101 is disposed in an air flow formed between adjacent main blades.

  In the proposal as in Patent Document 2, air flows along the positive pressure surface 103 and the negative pressure surface 102 of the main blade 100 by the rotation of the fan. At this time, the air flowing along the suction surface 102 tends to be separated from the suction surface 102 toward the pressure surface 103 of the adjacent blade, and a shear flow is formed behind the outer end 104 of the main blade 100. There is a risk. However, if the auxiliary blade 101 as described above is provided, the air that has passed through the main blade 100 flows along the positive pressure surface 105 and the negative pressure surface 106 of the auxiliary blade 101. Since the generation of the shear flow behind the main blade 100 is reliably suppressed, the air blowing performance and noise characteristics are improved.

However, in the proposal as described in Patent Document 2, there is a risk that the blades 100 and 101 made of resin or the like, in particular, the auxiliary blade 101 may be deformed by the fan rotation. May be deformed as indicated by a dotted line in FIG. 7 and may rarely come into contact with the trailing edge portion 104 of the main blade 100 in the air flow direction.
JP 60-156997 A Japanese Patent Laid-Open No. 2004-060447

For this reason, although the application is still unpublished, a proposal as shown in FIG. 8 has been made by the present applicant (Patent Document 3). In FIG. 8, the trailing edge 104 in the air flow direction of the main blade 100 and the leading edge 107 in the air flow direction of the auxiliary blade 101 are connected by the reinforcing ribs 108. The deformation of the portion 107 is reliably prevented. Therefore, the original function of the auxiliary blade 101 is ensured, and the blowing performance and noise characteristics are improved.
Japanese Patent Application No. 2003-399177

  However, when the centrifugal multiblade fan having the reinforcing ribs 108 as described above is integrally molded with resin or the like, the presence of the reinforcing ribs 108 makes it impossible to release the mold from the mold as it is. Therefore, the mold structure is complicated, and there is a risk that the durability of the mold and the productivity of the centrifugal multiblade fan may be reduced. Moreover, there is a possibility that the manufacturing cost of the mold and the manufacturing cost of the centrifugal multiblade fan may increase.

  Therefore, an object of the present invention is to reduce the manufacturing cost of the mold while simplifying the mold structure and improving the durability of the mold, thereby enabling efficient production at low cost, and excellent air blowing performance and noise. An object of the present invention is to provide a centrifugal multiblade fan having characteristics.

In order to solve the above problems, a centrifugal multiblade fan according to the present invention has a plurality of blades arranged in a circumferential direction around a rotation axis, and the blades are arranged in a plurality of main blades arranged radially inside. A plurality of auxiliary blades arranged radially outside and in an air flow formed between adjacent main blades, and one end sides of the plurality of auxiliary blades in the direction along the rotation axis are connected to each other by a connection ring. A multi-blade fan section connected to the drive plate connected to the rotary shaft at the other end side, and connected to the drive plate at the other end side of the main blade; In the centrifugal multiblade fan that sucks air from the inner diameter end side and discharges air from the outer diameter end side in the portion between adjacent blades, a plurality of main blades arranged radially inward , Radially outward, and an auxiliary blade disposed in the airflow formed between each adjacent main blades, said rotating said auxiliary blade pressure side of each main blade and respective main blade A part of the blade is connected by a reinforcing rib in the direction along the axis , and reaches the one end of the blade in the direction along the rotation axis from the main blade trailing edge side to the auxiliary blade suction surface side. A direction that extends along the suction surface and then reaches the pressure surface side of the adjacent auxiliary blade located on the suction surface side of the auxiliary blade, and is surrounded by a line extending from there to the trailing edge of the main blade, and intersects each blade. a first planar portion extending, at the other end, leads from the main blade trailing edge side to the positive pressure side of the adjacent auxiliary blades, said main blade trailing edge after extending along the adjacent auxiliary blades pressure surface Surrounded by a line leading to Constitute a second planar portion extending in a direction intersecting the blade, the multiblade fan so that the first planar portion and a second planar portion do not overlap each other as viewed from a direction along the rotation axis It consists of what is arrange | positioned alternately at the circumferential direction of a part.

  In the centrifugal multiblade fan as described above, the air flow direction trailing edge of each adjacent main blade and the air flow direction front edge of each auxiliary blade are connected by the first and second planar portions. In addition, since each planar portion is provided at both end portions of each blade in the direction along the rotation axis, deformation of the front edge portion of the auxiliary blade toward the main blade side is reliably prevented. Therefore, the original function of the auxiliary blade is reliably ensured, so that the blowing performance and noise characteristics of the centrifugal multiblade fan can be improved.

  Further, since the main blades and the auxiliary blades on the pressure side of the main blades are connected by the reinforcing ribs, the deformation of the auxiliary blades can be prevented more reliably.

Furthermore, in the centrifugal multiblade fan as described above, the first and second planar portions are alternately arranged in the circumferential direction of the multiblade fan portion so as not to overlap each other when viewed from the direction along the rotation axis. Therefore, even when the first and second planar portions are formed at the end portions in the direction along the rotation axis of each blade, the first and second portions are not provided to the mold without providing a slide mechanism or the like. 2 planar portions can be formed. Further, if the first and second planar portions are alternately arranged in the circumferential direction of the multiblade fan portion as described above, the end surface in the direction along the rotation axis of the reinforcing rib can be used as a split surface of the mold. Therefore, the centrifugal multiblade fan having the reinforcing rib can be integrally formed without providing a slide mechanism or the like to the mold.

  Preferably, the first planar portion is formed integrally with the connection ring, and the second planar portion is formed integrally with the drive plate. In this way, if the first and second planar portions are formed integrally with other members, a substantial increase in the number of parts can be prevented, so that an increase in the cost of the centrifugal multiblade fan can be prevented.

In order to solve the above-mentioned problem, another centrifugal multiblade fan according to the present invention has a plurality of blades arranged in a circumferential direction around a rotation axis, and the rotation shafts of the plurality of blades have a plurality of blades. A multi-blade fan section connected at one end side in the direction along the drive plate connected to the rotating shaft and connected at the other end side by a connection ring, and a portion between adjacent blades by rotation of the multi-blade fan section; In the centrifugal multiblade fan that sucks air from the inner diameter end side and discharges air from the outer diameter end side, the blade is a plurality of main blades arranged on the radially inner side, a radially outer side, and The auxiliary blades disposed in the air flow formed between the adjacent main blades, and the main blades and the auxiliary blades on the pressure surface side of the main blades are partially in the direction along the rotation axis. There reinforcement Li Are connected by, wherein said other end viewed from the connection ring in the direction along the rotary shaft is provided with a notch on the surface of the other end of the connecting ring so as not to overlap with the reinforcing ribs Consists of things. In such a configuration, since the notch is provided on the surface on the other end side of the connecting ring in which the reinforcing rib is projected in the direction along the rotation axis, the end surface of the reinforcing rib in the direction along the rotation axis is formed on the mold. If the dividing surface is used, a centrifugal multiblade fan having reinforcing ribs can be integrally formed without providing a slide mechanism or the like to the mold.

  The arrangement position of the reinforcing rib is not particularly limited, but it is preferably provided at a substantially central portion in the longitudinal direction of the main blade and the auxiliary blade. If the reinforcing rib is provided at such a position, the auxiliary blade can be more reliably prevented from being deformed by the cooperative action of the reinforcing rib and the first and second planar portions.

  The reinforcing rib is preferably arranged so as to connect the trailing edge of the main blade in the air flow direction and the leading edge of the auxiliary blade in the air flow direction. That is, between the two blades, the positions of the rear edge portion of the main blade in the air flow direction and the front edge portion of the auxiliary blade in the air flow direction are the closest. Therefore, if the reinforcing blade is disposed at such a position, the two blades can be connected at the shortest distance.

  It is preferable that the inner diameter end portion of the auxiliary blade is disposed on the inner side in the fan radial direction than the outer diameter end portion of the main blade. According to such a configuration, it is possible to suppress the deviation of the air flow toward the pressure surface side of the adjacent main blade due to the separation of air on the suction surface when passing through the main blade.

  Further, the auxiliary blade has a distance between the inner diameter end of the auxiliary blade and the pressure surface of the other main blade adjacent to the inner diameter end of the auxiliary blade rather than a distance between the inner diameter end of the auxiliary blade and the pressure surface of the other main blade. It is preferable to arrange so that becomes larger. According to such a configuration, since the air flow to be separated from the pressure surface of the main blade flows along the pressure surface and the suction surface of the auxiliary blade, separation and shear flow in the wake flow are effectively prevented. Can be suppressed.

The main blade and / or the auxiliary blade is preferably formed in a cross-sectional wing shape in which the thickness gradually increases from the blade leading edge side and then gradually decreases toward the blade trailing edge .

  In the centrifugal multiblade fan according to the present invention, the first and second planar portions and the reinforcing rib that can reliably prevent the deformation of the auxiliary blade can be formed without providing a slide mechanism or the like to the mold. Thus, it is possible to provide a centrifugal multiblade fan having excellent air blowing performance and noise characteristics, and capable of greatly reducing the manufacturing cost by simplifying the mold structure.

The centrifugal multiblade fan according to the present invention will be described below with reference to the drawings. 1 to 4 show a centrifugal multiblade fan according to a first embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes a centrifugal multiblade fan. In addition, in FIG. 1, the half part of the centrifugal multiblade fan is displayed. The centrifugal multiblade fan 1 has a multiblade fan section 4 having a large number of main blades 2 and auxiliary blades 3. A disc-shaped drive plate 5 is provided at the end of the blades 2 and 3 on the side opposite to the air suction side, and is connected to all the blades 2 and 3. A boss portion 6 is formed at the center of the drive plate 5, and a rotation shaft 6 a is mounted in the boss portion 6, and the drive plate 5 and all the blades 2, 3 are moved in a predetermined direction (by rotation of the rotation shaft 6 a). It is rotated in the direction of the arrow in FIG. An annular connection ring 7 is provided at the air suction side end of the blades 2, 3. The connection ring 7 connects all the blades 2, 3 to each other and plays a role of reinforcement.

  The main blade 2 is disposed on the radially inner side. In addition, the auxiliary blade 3 is disposed in the air flow formed radially outside and between the adjacent main blades. In this embodiment, as shown in FIGS. 3 and 4, both blades are arranged such that the front edge portion 10 of the auxiliary blade 3 is located on the inner side than the rear edge portion 9 of the main blade 2. Reference numeral 8 denotes a front edge portion of the main blade 2, and 11 denotes a rear edge portion of the auxiliary blade 3.

  Both the main blade 2 and the auxiliary blade 3 have a blade shape in which the blade thickness increases gradually and then gradually decreases. In the present embodiment, the main blade 2 is formed larger in thickness, warpage, and chord length than the auxiliary blade 3, and is designed so that the suction capability of the main blade 2 is increased.

  The main blade 2 and the auxiliary blade 3 are connected by a reinforcing rib 18. In the present embodiment, as shown in FIG. 2, the reinforcing rib 18 is provided at one location in the substantially central portion in the longitudinal direction of the blades 2 and 3.

  A first planar portion 16 is provided at one end of the main blade 2 and the auxiliary blade 3 (hereinafter simply referred to as each blade) in the direction along the rotation axis. The first planar portion 16 extends from the trailing edge 9 side of the main blade 2 to the suction surface 15 side of the auxiliary blade 3 (line segment A) and extends along the suction surface 15 of the auxiliary blade 3 ( Line B) A direction that extends to the pressure surface 14 side of the adjacent auxiliary blade 3 (line C) and is surrounded by a line (line D) from there to the rear edge 9 of the main blade 2 and intersects each blade. It is formed in the planar part which spreads. In FIG. 3, the first planar portion 16 is not displayed in a cross section, but is hatched to clearly show the first planar portion 16 with respect to other portions.

  On the other hand, a second planar portion 17 is provided at the other end of each blade. The second planar portion 17 extends from the trailing edge 9 side of the main blade 2 to the pressure surface 14 side of the auxiliary blade 3 (segment E) and extends along the pressure surface 14 of the auxiliary blade 3 ( Line segment F) It is surrounded by a line (line segment G) reaching the rear edge 9 of the main blade 2 and is formed into a planar portion that extends in a direction intersecting each blade. In FIG. 4, the second planar portion 17 is not displayed in a cross section, but is hatched to clearly show the second planar portion 17 with respect to other portions.

  As shown in FIGS. 3 and 4, the first planar portion 16 and the second planar portion 17 have the main blade 2 and the auxiliary blade 3 opposite to both ends in the direction along the rotation axis. The multiblade fan portions 4 are alternately arranged in the circumferential direction. In the present embodiment, the first planar portion 16 is formed integrally with the connection ring 7. Further, the second planar portion 17 is formed integrally with the drive plate 5.

  In the multiblade fan 1 according to this embodiment, when the multiblade fan unit 4 is rotated, air flows along the pressure surface 12 and the suction surface 13 of the main blade 2. When air passes through the main blade 2, the air flowing along the suction surface 13 of the main blade 2 tends to peel off from the suction surface 13, and a shear flow is formed behind the rear edge 9 of the main blade 2. It tends to be. Here, the auxiliary blade 3 is arranged inside the air flow passing between the main blades 2. Therefore, the air that has passed through the main blade 2 flows along the pressure surface 14 and the suction surface 15 of the auxiliary blade 3, so that the air flow is separated and the air flow is biased toward the pressure surface 12 side of the main blade 2. Generation of shear flow is suppressed, and air blowing performance and noise characteristics are improved.

  Further, in the centrifugal multiblade fan 1 as in the present embodiment, the air flow direction rear edge 9 of each main blade 2 adjacent to each other and the air flow direction front edge 10 of each auxiliary blade 3 are the first. The planar portions 16 and the second planar portion 17 are connected to each other, and the planar portions 16 and 17 are provided at both end portions in the direction along the rotation axis of each blade. Deformation of the leading edge 10 in the flow direction toward the main blade is reliably prevented. In addition, a reinforcing rib that connects the air flow direction rear edge 9 of each adjacent main blade 2 and the air flow direction front edge 10 of each auxiliary blade 3 to the central portion in the direction along the rotation axis of each blade. 18 is provided. Therefore, the deformation of the leading edge 10 of the auxiliary blade 2 in the air flow direction to the main blade 2 side is surely prevented, and the original function of the auxiliary blade is reliably ensured. The characteristics can be further improved.

  Further, the first planar portion 16 and the second planar portion 17 are arranged in the circumferential direction of the multiblade fan unit 4 with respect to both ends in the direction along the rotation axis of each main blade 2 and each auxiliary blade 3. Therefore, the planar portions 16 and 17 can be formed without providing a slide mechanism or the like to the mold. Moreover, if the planar parts 16 and 17 are alternately arranged in the circumferential direction of the multiblade fan part 4 as described above, the centrifugal multiblade fan 1 having the reinforcing ribs 18 can be easily integrally formed. That is, if the end face 18a in the direction along the rotation axis of the reinforcing rib 18 is a mold dividing surface, the reinforcing rib 18 can be integrally formed without providing a slide mechanism or the like to the mold. For example, if a step portion extending in the sliding direction of the mold is formed in the movable die and the fixed die and the reinforcing rib 18 is formed by combining the step portions, the centrifugal multiblade having the reinforcing rib 18 is formed. The fan 1 can be easily integrally formed.

  5 and 6 show a centrifugal multiblade fan according to a second embodiment of the present invention. The basic configuration of the centrifugal multiblade fan in this embodiment is substantially the same as that of the centrifugal multiblade fan in the first embodiment, and has a plurality of blades arranged in the circumferential direction around the rotation axis. ing. One end side of the plurality of blades in the direction along the rotation axis is connected to a drive plate 19 connected to the rotation axis, and the other end side is provided with a multiblade fan portion 21 connected to each other by a connection ring 20. Yes. The blade has a plurality of main blades 22 arranged radially inward, and auxiliary blades 23 arranged radially outside and in an air flow formed between adjacent main blades, and are adjacent to each other. The trailing edge 24 in the air flow direction of each main blade 22 and the leading edge 25 in the air flow direction of each auxiliary blade 22 are connected by a reinforcing rib 26 provided at a substantially central portion in the direction along the rotation axis of each blade. ing. Further, a notch 27 is provided on the projection surface of the reinforcing rib 25 to the connection ring 20.

  In such a configuration, since the notch 27 is provided on the projection surface of the reinforcing rib 26 to the connection ring 20 in the direction along the rotation axis, the movable mold can be slid through the notch 27. . Therefore, if the end face 26a in the direction along the rotation axis of the reinforcing rib 26 is used as a dividing surface of the mold, the centrifugal multiblade fan having the reinforcing rib 26 is integrally formed without providing a sliding mechanism or the like to the mold. be able to.

  The present invention can be suitably used for a centrifugal multiblade fan, in particular, a centrifugal multiblade fan used as a blower of a vehicle air conditioner.

It is the top view which displayed the part of the centrifugal multiblade fan concerning a 1st embodiment of the present invention. It is a half section display side view of the centrifugal multiblade fan of FIG. FIG. 3 is a III arrow view of the centrifugal multiblade fan of FIG. 2. FIG. 4 is an IV arrow view of the centrifugal multiblade fan of FIG. 2. FIG. 6 is a partially enlarged plan view of a centrifugal multiblade fan according to a second embodiment of the present invention. It is a partial expanded bottom view of the centrifugal multiblade fan which concerns on the 2nd embodiment of this invention. It is a partial expanded sectional view of the blade part of the centrifugal multiblade fan concerning the previous proposal of the present applicant. It is a partial expanded sectional view of the blade part of the centrifugal multiblade fan concerning another proposal of the present applicant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Centrifugal multiblade fan 2,22 Main blade 3,23 Auxiliary blade 4,21 Multiblade fan part 5,19 Drive plate 6 Boss part 6a Rotating shaft 7,20 Connection ring 8 Front edge part of main blade 9,24 Main Blade trailing edge 10, 25 Auxiliary blade leading edge 11 Auxiliary blade trailing edge 12 Main blade pressure surface 13 Main blade suction surface 14 Auxiliary blade pressure surface 15 Auxiliary blade suction surface 16 First surface -Shaped part 17 Second planar part 18, 26 Reinforcing rib 18 a, 26 a End face 27 Notch

Claims (10)

A plurality of blades arranged in a circumferential direction around a rotation axis, the blades being formed between a plurality of main blades arranged radially inside and radially outside and between adjacent main blades; The auxiliary blade is disposed in the air flow, and one end side of the plurality of auxiliary blades in the direction along the rotation axis is connected to each other by a connection ring, and the other end side is connected to a drive plate connected to the rotation axis. And the other end side of the main blade is provided with a multi-blade fan portion connected to the drive plate, and air is sucked from the inner diameter end side of each portion between adjacent blades by rotation of the multi-blade fan portion, and the outer diameter end. in centrifugal multiblade fan for discharging air from the parts side, contact some of the reinforcing ribs in the direction in which the auxiliary blade pressure side of each main blade and respective main blades along the rotational axis It is, and the auxiliary blade at one end of the direction along the rotation shaft of each blade, reaches from the main blade trailing edge side to the auxiliary blade suction side, after extending along the auxiliary blade suction surface A first planar portion extending to the pressure surface side of the adjacent auxiliary blade located on the suction surface side of the blade, surrounded by a line extending from there to the trailing edge of the main blade, and extending in a direction crossing each blade, and the other end To the pressure side of the adjacent auxiliary blade from the trailing edge side of the main blade, and is surrounded by a line extending along the pressure surface of the adjacent auxiliary blade and then to the trailing edge of the main blade, and intersects each blade. A circumferential direction of the multi-blade fan portion so that the first planar portion and the second planar portion do not overlap each other when viewed from the direction along the rotation axis. Characterized by staggered arrangement Multi-blade fan.   The centrifugal multiblade fan according to claim 1, wherein the first planar portion is formed integrally with the connection ring, and the second planar portion is formed integrally with the drive plate. It has a plurality of blades arranged in the circumferential direction around the rotation axis, one end side of the plurality of blades along the rotation axis is connected to a drive plate connected to the rotation shaft, and the other end side is a connection ring And a multi-blade fan unit connected to each other by a centrifugal multi-blade that sucks air from the inner diameter end side and discharges air from the outer diameter end side by rotating the multi-blade fan unit. In the fan, the blade has a plurality of main blades arranged radially inward, and auxiliary blades arranged radially outside and in an air flow formed between adjacent main blades, some in the direction in which the auxiliary blade pressure side of each main blade and respective main blade along the rotary shaft is connected by the reinforcing ribs, connected as viewed from the other end side in the direction along the rotation axis phosphorus Centrifugal multiblade fan but it characterized in that a notch on the surface of the other end of the connecting ring so as not to overlap with the reinforcing ribs.   The centrifugal multiblade fan according to any one of claims 1 to 3, wherein the reinforcing rib is provided at a substantially central portion in a longitudinal direction of the main blade and the auxiliary blade.   The centrifugal multiblade fan according to any one of claims 1 to 4, wherein the reinforcing rib connects the trailing edge of the main blade in the air flow direction and the leading edge of the auxiliary blade in the air flow direction.   The centrifugal multiblade fan according to any one of claims 1 to 5, wherein an inner diameter end portion of the auxiliary blade is disposed radially inside than an outer diameter end portion of the main blade.   The distance between the auxiliary blade and the suction surface of the other main blade adjacent to the inner diameter end of the auxiliary blade is larger than the distance between the inner diameter end of the auxiliary blade and the pressure surface of one main blade adjacent to the auxiliary blade. The centrifugal multiblade fan according to claim 1, wherein the centrifugal multiblade fan is arranged so as to be large.   The centrifugal multiblade fan according to any one of claims 1 to 7, wherein the main blade and the auxiliary blade are integrally formed.   9. The main blade and / or the auxiliary blade is formed in a cross-sectional wing shape in which the thickness once increases gradually from the blade leading edge side and then gradually decreases toward the blade trailing edge. The centrifugal multiblade fan according to any one of the above.   The centrifugal multiblade fan according to any one of claims 1 to 9, wherein the whole is made of resin and integrally molded.

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