JP4726503B2 - 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. Therefore, in the centrifugal multiblade fan, the vortex noise due to the separation causes the noise in the 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 deviation of the air flow by narrowing the interval on the radially outer end side of each blade may be considered. As the relative speed increases, 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 addition, when the entire centrifugal multiblade fan is made of an integrally molded product made of resin, the blades are deformed, and the distance between the radially outer ends of the blades tends to be narrowed, which may reduce the blowing performance and noise characteristics. . In particular, at both ends in the direction along the rotation axis of the blade, sufficient strength cannot be secured and the blade is likely to be deformed.

  In order to solve the problem of the above-mentioned deterioration of the air blowing performance and noise characteristics, the applicant has already proposed as shown in FIG. 9 (Patent Document 2). In FIG. 9, 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, even in the proposal as in Patent Document 2, the blades 100 and 101 made of resin or the like, in particular, the auxiliary blade 101 may be deformed by the rotation of the fan. In some cases, the leading edge portion 107 of the auxiliary blade 101 in the air flow direction may be used. May be deformed as indicated by the dotted line in the figure, and may rarely come into contact with the trailing edge 104 of the main blade 100 in the air flow direction.
JP 60-156997 A Japanese Patent Laid-Open No. 2004-060447

  SUMMARY OF THE INVENTION An object of the present invention is to provide a centrifugal multiblade fan that can reliably prevent blade deformation and improve air blowing performance and noise 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 one end side of the plurality of blades in the direction along the rotation axis is A multi-blade fan section connected to each other by a connection ring and connected to a drive plate connected to the rotating shaft at the other end side, and by the rotation of the multi-blade fan section, an inner diameter end portion side portion between each adjacent blade In the centrifugal multiblade fan that sucks air from the outer diameter end side and discharges air from the outer diameter end side, the blade has one end in the direction along the rotation axis, and the blade trailing edge side to the suction surface of the blade. In the direction crossing the blade, it reaches the pressure surface side and rear edge side portion of the adjacent blade located rearward in the rotational direction, and extends from there to the rear edge portion of the blade. The first to spread And the planar portion of the other end portion of the direction along the rotational axis of the blade, from the leading edge side of the adjacent blade, suction side and the blade after extending along the pressure side of the adjacent blade A second planar portion extending to a portion on the front edge side , surrounded by a line extending from there to the front edge portion of the adjacent blade, and extending in a direction intersecting with the blade, and the first planar portion; The second planar portions are alternately arranged in the circumferential direction of the multi-blade fan portion so as not to overlap each other when viewed from the direction along the rotation axis . In such a configuration, the first and second planar portions are provided at both ends in the direction along the rotation axis of the blade, and both ends in the direction along the rotation axis of the blade that is particularly easily deformed are reinforced to strengthen the portion. Therefore, the blade is reliably prevented from being deformed. Therefore, it is possible to reliably improve the blowing performance and noise characteristics. Further, since the first planar portion and the second planar portion 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 , the slide mechanism is mounted on the mold. It is possible to easily mold with a mold having a relatively simple structure.

Said blade is formed in a cross-sectional airfoil shape that decreases toward the gradually blade trailing edge once gradually increased thereafter from the blade leading edge side thickness.

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. And a multi-blade fan portion connected to a drive plate whose one end side along the connecting direction is connected to each other by a connection ring and the other end side is connected to the rotating shaft, and a portion between adjacent blades by rotation of the multi-blade fan portion 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 arranged in the air flow formed between the adjacent main blades, and located at one end in the direction along the rotation axis of each blade, forward from the main blade trailing edge side in the rotation direction. appoint Reaches the site of the blade suction side and front edge side of the leads to the site of pressure side and front edge side of the adjacent auxiliary blades positioned behind the rotating direction after extending along the auxiliary blade suction surface, A first surface portion surrounded by a line extending from there to the rear edge of the main blade and extending in a direction intersecting with each blade, and a pressure surface of the adjacent auxiliary blade from the main blade rear edge to the other end. It reaches the site of the side and front edge side, bounded by a line leading to the main blade trailing edge after extending along the pressure side of the adjacent auxiliary blades, a second planar extending in a direction intersecting with each blade And the first planar portion and the second planar portion are alternately arranged in the circumferential direction of the multi-blade fan portion so that they do not overlap each other when viewed from the direction along the rotation axis . It consists of what is characterized by. In such a configuration, the first and second planar portions are provided at both ends in the direction along the rotation axis of the blade, and both ends in the direction along the rotation axis of the blade that is particularly easily deformed are reinforced to strengthen the portion. Therefore, the blade is reliably prevented from being deformed. Therefore, it is possible to reliably improve the blowing performance and noise characteristics. Further, since the first planar portion and the second planar portion 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 , the slide mechanism is mounted on the mold. The first and second planar portions can be easily formed integrally with a mold having a relatively simple structure without providing the like.

  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 quickly 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 on the upstream side.

  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.

  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 the centrifugal multiblade fan according to the present invention, the first and second planar portions capable of reliably preventing the deformation of the auxiliary blade can be integrally formed without providing a slide mechanism or the like to the mold. Thus, it is possible to provide a centrifugal multiblade fan that has excellent air blowing performance and noise characteristics, and that can greatly reduce 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. FIG. 1 shows a part of the centrifugal multiblade fan. The centrifugal multiblade fan 1 has a multiblade fan section 4 having a large number of blades 2. A disk-shaped drive plate 5 is provided at the end of the blade 2 on the side opposite to the air suction side, and is connected to all the blades 2. A boss 6 is formed at the center of the drive plate 5, and a rotating shaft 6 a is mounted in the boss 6, and the drive plate 5 and all the blades 2 are moved in a predetermined direction (FIG. 1) by the rotational drive of the rotating shaft 6 a. (In the direction of the arrow). An annular connection ring 7 is provided at the air suction side end of the blade 2, and the connection ring 7 connects all the blades 2 to each other and plays a role of reinforcement.

  A plurality of blades 2 are arranged in the circumferential direction. An air flow is formed between each adjacent blade 2. The blade 2 has a blade shape in which the blade thickness is gradually increased from the front edge portion 8 side and then gradually decreased toward the rear edge portion 9.

  A first planar portion 10 as shown in FIG. 3 is provided at one end of the blade 2 in the direction along the rotation axis 6a. The first planar portion 10 is not displayed in a cross section, but is hatched to clearly show the first planar portion 10 with respect to other portions. The first planar portion 10 extends from the trailing edge 9 side of the blade 2 along the suction surface 13 of the blade 2 (line segment A) and reaches the pressure surface 12 side of the adjacent blade 2 (line segment). B), which is surrounded by a line (line segment C) extending from there to the rear edge 9 of the blade 2 and formed integrally with the connection ring 7 as a surface extending in a direction intersecting the blade 2.

  On the other hand, a second planar portion 11 as shown in FIG. 4 is provided at the other end of the blade 2 in the direction along the rotation axis 6a. In addition, although the 2nd planar part 11 is not necessarily displayed by the cross section, in order to clearly show the 2nd planar part 11 with respect to another site | part, it has given hatching. The second planar portion 11 extends from the trailing edge 9 side of the blade 2 along the pressure surface 12 of the blade 2 (line segment D) and reaches the suction surface 13 side of the adjacent blade 2 (line segment). E), which is surrounded by a line (line segment F) extending from there to the rear edge 9 of the blade 2 and formed integrally with the drive plate 5 as a surface extending in a direction intersecting the blade 2. In the present embodiment, the first planar portion 10 is formed integrally with the connection ring 7. Further, the second planar portion 11 is formed integrally with the drive plate 5.

  As apparent from the comparison between FIGS. 3 and 4, the first planar portion 10 and the second planar portion 11 are multi-blade fan portions with respect to both end portions in the direction along the rotation axis 6 a of the blade 2. 4 are arranged alternately in the circumferential direction.

  In this embodiment, the first planar portion 10 and the second planar portion 11 are provided at both ends of the blade 2 in the direction along the rotational axis 6a, and the direction along the rotational axis 6a of the blade 2 that is particularly easily deformed. Since both ends of the blade are reinforced and the strength of the portion is improved, deformation of the blade 2 is reliably prevented. Therefore, it is possible to reliably improve the blowing performance and noise characteristics. Further, since the first planar portion 10 and the second planar portion 11 are alternately arranged in the circumferential direction of the multiblade fan portion 4 with respect to both ends of the blade 2 in the direction along the rotation axis 6a. The first planar portion 10 and the second planar portion 11 can be easily formed integrally with a mold having a relatively simple structure without providing a slide mechanism or the like in the mold.

  5 to 8 show a centrifugal multiblade fan according to a second embodiment of the present invention. The centrifugal multiblade fan 14 has a multiblade fan section 17 having a large number of main blades 15 and auxiliary blades 16. A disc-shaped drive plate 18 is provided at the end of the blades 15, 16 on the side opposite to the air suction side, and is connected to all the blades 15, 16. A boss portion 19 is formed at the center of the drive plate 18, and a rotating shaft 19 a is mounted in the boss portion 19, and the drive plate 18 and all the blades 15, 16 are moved in a predetermined direction (by rotation driving of the rotating shaft 19 a). It is rotated in the direction of the arrow in FIG. An annular connection ring 20 is provided at the air suction side end of the blades 15, 16. The connection ring 20 connects all the blades 15, 16 to each other and plays a role of reinforcement.

  The main blade 15 is disposed on the radially inner side. In addition, auxiliary blades 16 are disposed in the air flow formed radially outside and between the adjacent main blades 15. In the present embodiment, as shown in FIG. 7, both blades are arranged such that the front edge 23 of the auxiliary blade 16 is on the inner side than the rear edge 22 of the main blade 15. Reference numeral 21 denotes a front edge portion of the main blade 15, and reference numeral 24 denotes a rear edge portion of the auxiliary blade 16.

  Both the main blade 15 and the auxiliary blade 16 have a blade shape in which the blade thickness increases gradually and then gradually decreases. In this embodiment, the main blade 15 is formed larger in thickness, warpage, and chord length than the auxiliary blade 16, and is designed so that the suction performance of the main blade 15 is increased.

  One end of the main blade 15 and the auxiliary blade 16 in the direction along the rotation shaft 19a extends from the rear edge 22 side of the main blade 15 to the negative pressure surface 28 side of the auxiliary blade 16 (line segment G). 16 extends along the negative pressure surface 28 (line segment H), reaches the pressure surface 27 side of the adjacent auxiliary blade 16 (line segment I), and then extends to the rear edge 22 of the main blade 15 (line segment). A first planar portion 29 is provided which is surrounded by J) and extends in a direction intersecting with each blade. In FIG. 7, the first planar portion 29 is not displayed in a cross section, but is hatched to clearly show the first planar portion 29 with respect to other portions.

  On the other hand, the other end of the main blade 15 and the auxiliary blade 16 in the direction along the rotation shaft 19a extends from the rear edge 22 side of the main blade 15 to the positive pressure surface 27 side of the auxiliary blade 16 (line segment K). After extending along the pressure surface 27 of the auxiliary blade 16 (line segment L), the second blade is surrounded by a line (line segment M) reaching the rear edge 22 of the main blade 15 and spreads in a direction intersecting each blade. The planar portion 30 is provided. In FIG. 8, the second planar portion 30 is not displayed in a cross section, but is hatched to clearly show the second planar portion 30 with respect to other portions.

  As shown in FIGS. 7 and 8, the first planar portion 29 and the second planar portion 30 are opposite to both end portions in the direction along the rotation shaft 19 a of each main blade 15 and each auxiliary blade 16. The multiblade fan portions 17 are alternately arranged in the circumferential direction. In the present embodiment, the first planar portion 29 is formed integrally with the connection ring 20. Further, the second planar portion 30 is formed integrally with the drive plate 18.

  In the multiblade fan 14 according to this embodiment, when the multiblade fan unit 17 is rotated, air flows along the pressure surface 25 and the suction surface 26 of the main blade 15. When air passes through the main blade 15, the air flowing along the suction surface 26 of the main blade 15 tends to be separated from the suction surface 26, and a shear flow is formed behind the rear edge 22 of the main blade 15. It is easy to be done. However, the auxiliary blade 16 is arranged inside the air flow passing between the main blades 15. Therefore, the air that has passed through the main blade 15 flows along the pressure surface 27 and the suction surface 28 of the auxiliary blade 16, so that the air flow is separated and the air flow is biased toward the pressure surface 25 side of the main blade 15. Generation of shear flow is suppressed, and air blowing performance and noise characteristics are improved.

  In the centrifugal multiblade fan 14 as in the present embodiment, the air flow direction rear edge 22 of each main blade 15 and the air flow direction front edge 23 of each auxiliary blade 16 adjacent to each other are the first. Since the planar portions 29 and 30 are connected by the planar portion 29 and the second planar portion 30, and the planar portions 29 and 30 are provided at both end portions in the direction along the rotation shaft 19 a of each blade, Deformation of the leading edge 23 in the air flow direction toward the main blade 15 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 further improved.

  In addition, the first planar portion 29 and the second planar portion 30 are arranged so that the multiblade fan portion 17 has the opposite end portions in the direction along the rotation shaft 19a of each main blade 15 or each auxiliary blade 16. Since they are alternately arranged in the circumferential direction, even when the first planar portion 29 and the second planar portion 30 are formed at the end portions in the direction along the rotation shaft 19a of each blade, the mold The planar portions 29 and 30 can be formed without providing a slide mechanism or the like.

  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. It is the top view which displayed the part of the centrifugal multiblade fan which concerns on the 2nd embodiment of this invention. FIG. 6 is a half sectional display side view of the centrifugal multiblade fan of FIG. 5. It is a VII arrow line view of the centrifugal multiblade fan of FIG. It is a VIII arrow line view of the centrifugal multiblade fan of FIG. It is a partial expanded sectional view of the blade part of the centrifugal multiblade fan concerning the previous proposal of the present applicant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,14 Centrifugal multiblade fan 2 Blade 4,17 Multiblade fan part 5,18 Drive plate 6,19 Boss part 6a, 19a Rotating part 7,20 Connection ring 8 Blade front edge part 9 Blade rear edge part 10 , 29 First planar portion 11, 30 Second planar portion 12 Blade pressure surface 13 Blade suction surface 15 Main blade 16 Auxiliary blade 21 Front edge portion of main blade 22 Rear edge portion of main blade 23 Auxiliary blade 24 Leading edge of auxiliary blade 25 Pressure surface of main blade 26 Negative pressure surface of main blade 27 Positive pressure surface of auxiliary blade 28 Negative pressure surface of auxiliary blade

Claims (8)

A drive having a plurality of blades arranged in a circumferential direction around a rotation axis, one end side of the plurality of blades along the rotation axis being connected to each other by a connection ring, and the other end side being connected to the rotation shaft Centrifugal type multi-blade having a multi-blade fan section connected to a plate and sucking air from the inner diameter end side and discharging air from the outer diameter end section by rotating the multi-blade fan section In the fan, the pressure surface side of an adjacent blade positioned rearward in the rotation direction after extending along the suction surface of the blade from the rear edge side of the blade to one end portion in the direction along the rotation axis of the blade And a first planar portion extending to a portion on the rear edge side , surrounded by a line extending from there to the rear edge portion of the blade, and extending in a direction intersecting the blade, and in a direction along the rotation axis of the blade On the other end From the front edge portion of the adjacent blade, reaches the suction side and part of the front edge side of the blade after extending along the pressure side of the adjacent blade, a line leading from there to the front edge portion of the adjacent blade And a second planar portion extending in a direction intersecting with the blade 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. The blades are alternately arranged in the circumferential direction of the multi-blade fan part, and the blades are formed in a blade cross-sectional shape in which the thickness increases gradually from the blade leading edge side and then gradually decreases toward the blade trailing edge part. A centrifugal multi-blade fan characterized by A drive having a plurality of blades arranged in a circumferential direction around a rotation axis, one end side of the plurality of blades along the rotation axis being connected to each other by a connection ring, and the other end side being connected to the rotation shaft Centrifugal type multi-blade having a multi-blade fan section connected to a plate and sucking air from the inner diameter end side and discharging air from the outer diameter end section by rotating the multi-blade fan section In the fan, the blade includes a plurality of main blades arranged radially inward, and auxiliary blades arranged radially outside and in an air flow formed between adjacent main blades, at one end of the direction along the rotation axis of the blade, leads from the main blade trailing edge side portion of the suction side and front edge side of the auxiliary blade located in front the rotation direction, along the auxiliary blade suction surface The Reaches the pressure side and part of the rear edge side of the adjacent auxiliary blades positioned behind the Vita after rotation direction, bounded by a line extending from there to the edge after the main blade extends in a direction intersecting with each blade a first planar portion, the other end, leads from the main blade trailing edge side portion of the pressure side and front edge side of the adjacent auxiliary blades, extending along the pressure side of the adjacent auxiliary blades bounded by a line leading to the rear the main blade trailing edge, constitute a second planar portion extending in a direction intersecting with each blade, the rotation of the first planar portion and a second planar portion A centrifugal multiblade fan , wherein the multiblade fan portions are alternately arranged in the circumferential direction of the multiblade fan portion so as not to overlap each other when viewed from a direction along the axis . The centrifugal multiblade fan according to claim 2 , 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 greater than the distance between the inner diameter end of the auxiliary blade and the pressure surface of one of the main blades. The centrifugal multiblade fan according to claim 2 or 3 , which is arranged to be large. The centrifugal multiblade fan according to any one of claims 2 to 4 , wherein the main blade and the auxiliary blade are integrally formed. The main blades and / or auxiliary blades thicknesses are formed on the wing cross-section which decreases towards the gradually increased and then gradually blade trailing edge once from the blade leading edge side, the preceding claims 2 5 The centrifugal multiblade fan according to any one of the above. The centrifugal multiplicity according to any one of claims 1 to 6 , wherein the first planar portion is formed integrally with the connection ring, and the second planar portion is formed integrally with the drive plate. Wing fan. The centrifugal multiblade fan according to any one of claims 1 to 7 , wherein the whole is made of resin and integrally molded.

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