JPH07233798A - Multiblade air blower - Google Patents

Abstract

PURPOSE:To improve the air blasting performance by composing the tips at the suction side of the air and the like of main blades in a diagonal flow fan. CONSTITUTION:To a base 12 rotating around the axial center, numerous main blades 13 are provided in the ring form in the peripheral direction placing specific intervals. At the inner peripheral side at the tips of.the line of main blades 13, an inner bell-mouth 17 to guide to suck the air, and an outer bell- mouth 18 to guide to suck the air in the line of auxiliary blades 16 are formed. The outer angle parts of the tips of the main blades 13 are cut off by a projecting recess arc surface curved to the inner side along the diagonal direction to the axial center of the base 12 respectively, and to the outer surfaces of the recess arc surfaces of the line of the main blades 13, the trunks 15 of cylinder bodies suitable to the recess arc surfaces are inserted and fixed. By providing numerous auxiliary blades 16 to the recess arc form outer peripheral surfaces of the trunks 15, in the peripheral direction placing specific intervals, the system is composed into a diagonal flow auxiliary fan 14 to let flow the air to the outer side in the diagonal direction to the axial center of the base 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-blade blower suitable for a fan for an air conditioner, and more particularly to a multi-blade blower in which the air suction side tips of a large number of main blade rows are formed as a mixed flow fan section. Regarding

[0002]

2. Description of the Related Art Conventionally, as an example of this type of multi-blade fan, a structure shown in FIG. 10 is known. The multi-blade fan 1 is rotatably housed, for example, in a spiral casing (not shown), is long on the outer peripheral portion of one surface of the disk-shaped substrate 2, and is long in the direction parallel to the axis thereof. A large number of arcuate blades 3 inclined forward with respect to the rotation direction of 2 are arranged in an annular shape at predetermined intervals in the circumferential direction. A ring 4 is concentrically fixed to the substrate 2 at the tip of each blade 3 opposite to the substrate 2.

A boss portion 2a is formed in the axial center portion of the substrate 2, and a rotary shaft of a motor (not shown) is connected to the boss portion 2a to rotate in a predetermined direction, whereby an arrow in the drawing As shown in FIG. 5, the working fluid such as air is sucked from the inner peripheral side of the tip end portion of each blade 3 and is discharged laterally outward from the gap between the blades 3.

[0004]

However, in the conventional multi-blade fan 1 as described above, the axial direction (longitudinal direction) is measured from the air suction side tip portion of each blade 3, that is, the tip (upper end in FIG. 10) of each blade 3. ) Downward, for example, at the tip of about 25 to 40% of the total length, the air flow on the discharge side flows counter to the flow of other parts, reducing the aerodynamic efficiency and increasing the number of blades. There is a problem that the blowing performance of the blower 1 is reduced.

Therefore, the present invention has been made in consideration of such circumstances, and an object thereof is to improve air blowing performance by forming a tip end portion of each blade on the suction side of air etc. into a mixed flow fan portion. It is to provide a multi-blade blower capable of.

[0006]

The present invention is configured as follows in order to solve the above-mentioned problems.

The invention according to claim 1 of the present application (hereinafter, referred to as the first
Of the invention) has a substrate that rotates around an axis and a large number of main wings that are annularly arranged on the substrate at predetermined intervals in the circumferential direction. In a multi-blade blower that discharges the working fluid to the outer peripheral side of the main blade row, the tip outer corner portion of each of the main blades is a concave arc surface that is curved inward along an oblique direction with respect to the axis of the substrate. Each of the main blade rows is cut off, and a cylindrical body that fits the concave arc surface is externally fitted and fixed to the outer surface of each concave arc surface of the main wing row, and the concave arc-shaped outer peripheral surface of the cylindrical body is circumferentially spaced by a predetermined distance. By providing a large number of auxiliary blades, the auxiliary fluid is configured so as to flow the working fluid obliquely outward with respect to the axis of the substrate.

The invention according to claim 2 of the present application (hereinafter referred to as the second invention) is an inner bell mouth for guiding the working fluid so as to be sucked into the inner peripheral side of the leading end of the main wing row, and the inner bell mouth of this inner bell mouth. An outer bell mouth, which is arranged at a predetermined distance outside and guides the working fluid to be sucked from the outer end side in the axial direction of the aileron, and the outer bell mouth which is integrally formed with the sucked actuation And a guide ring for guiding the fluid flow outward in an oblique direction with respect to the axis of the substrate.

Further, in the invention according to claim 3 of the present application (hereinafter referred to as the third invention), the working fluid sucked between the auxiliary blade rows is oblique to the substrate axial center on the outer surface of the auxiliary blade rows. It is characterized in that a guide ring for guiding so as to flow outward in the direction is externally fitted and fixed.

Furthermore, the invention according to claim 4 of the present application (hereinafter referred to as the fourth invention) is an inner bell mouth for guiding the working fluid so as to be sucked into the inner peripheral side of the leading end of the main wing row,
An outer bell mouth, which is disposed outside the inner bell mouth at a predetermined interval and guides the working fluid so as to be sucked from the outer end side in the axial direction of the aileron.

Further, in the invention according to claim 5 of the present application (hereinafter referred to as the fifth invention), the auxiliary fan is 2 from the tip of the suction side when the axial length of each main blade is 100.
It is characterized in that it is formed at a tip end portion corresponding to a length of 5 to 40.

Further, in the invention according to claim 6 of the present application (hereinafter, referred to as a sixth invention), the guide ring is such that the inflow cross-sectional area and the outflow cross-sectional area of the working fluid into the auxiliary fan are substantially the same. It is characterized in that it is configured.

[0013]

[Action]

<First to Sixth Inventions> Conventionally, a tip end portion of each main wing on the side of suction of a working fluid such as air, for example, a tip end portion of 25 to 40% of the total length from the tip end to the base end side, its discharge side. The working fluid of is backflowing against the flow of parts other than the tip,
Although it is a part that lowers aerodynamic efficiency and lowers air blowing performance, in the present invention, since each of the main blade tips is configured as an auxiliary fan that functions as a mixed flow fan,
The backflow at the tip of the main blade row can be suppressed to enhance the air blowing performance at the tip of each main blade row, which in turn can improve the air blowing performance of the multi-blade blower as a whole.

<Second Invention> Since the inner bell mouth for guiding the working fluid such as air to be sucked in is provided on the inner peripheral side of the tip of the main blade row, the efficiency of sucking air or the like to the inner peripheral side of the tip of the main blade row is increased. As a result, the blow performance of the multi-blade blower as a whole can be improved.

Further, an outer bell mouth which guides the working fluid so as to suck the working fluid from the axially outer end side of the auxiliary blade, and an outer bell mouth which is integrally formed with the outer bell mouth to direct the flow of the sucked working fluid to the substrate axis. On the other hand, since it has a guide ring that guides outward in an oblique direction, it is possible to improve both suction efficiency and discharge efficiency of the working fluid to the auxiliary fan. For this reason, the blow performance of the auxiliary fan as a mixed flow fan can be improved, and thus the blow performance of the multi-blade blower as a whole can be improved.

<Third invention> A guide ring is provided on the outer surface of the auxiliary blade row so as to guide the working fluid sucked from the axially outer end of the auxiliary blade row so as to flow obliquely outward with respect to the substrate axis. Since the auxiliary fan is fixed by being fitted to the outer fan, the blow performance of the auxiliary fan as a mixed flow fan can be improved, and thus the blow performance of the multi-blade blower as a whole can be improved.

<Fourth Invention> Since the inner bell mouth for guiding the working fluid so as to be sucked in is provided on the inner peripheral side of the tip portion of the main blade row, the suction efficiency of the working fluid to the inner peripheral side of the tip portion of the main blade row can be increased.

Further, since the outer bell mouth for guiding the working fluid so as to be sucked in is provided on the outer end side in the axial direction of the auxiliary wing,
The suction efficiency of the working fluid to the auxiliary fan can be improved. As a result, it is possible to improve the blowing performance of the multi-blade blower as a whole.

<Sixth Invention> Since the guide ring is configured such that the cross-sectional area of the working fluid flowing into the auxiliary fan and the cross-sectional area of the outlet thereof are substantially the same, it is possible to improve the blowing efficiency.

[0020]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 9, the same or corresponding parts are designated by the same reference numerals.

FIG. 1 is a partially cutaway perspective view of an embodiment of the present invention, in which a multiblade blower 11 is a disc-shaped substrate 1.
A boss portion for coupling a rotation shaft of a fan motor (not shown) is formed at the shaft center portion of the second shaft, and is configured to rotate around the shaft center.

The substrate 12 has a large number of main wings 1 made of vertically elongated arc-shaped plates in the figure on the outer peripheral edge of one surface (the upper surface in FIG. 1).
3 are annularly arranged at a predetermined interval in the circumferential direction.

The main wings 13 are arranged parallel to the axis of the substrate 12, and are inclined forward with respect to a predetermined rotation direction of the substrate 12.

As shown in the longitudinal sectional view of FIG. 2, the tip end portion 13a of each main wing 13 on the working fluid intake side is constructed as a mixed flow auxiliary fan 14 having a function as a mixed flow fan.

That is, the mixed flow auxiliary fan 14 is provided for each main wing 1
The outer corner portion of the tip portion 13a of about 3 to about 40% of the total length from the tip (the upper end in FIG. 1 and FIG. 2) of the suction side of 3 etc. of the air 3 is curved inward from the vertical surface to the horizontal surface continuously. The concave arc surface 13b is cut off at the concave arc surface 13b, and the concave arc surface 13b of these 13 rows of main wings is cut off.
A concave arc surface that fits the concave arc surface 13b is formed on the outer peripheral surface of FIG.
A cylindrical body portion 15 that spreads in a trumpet shape toward the inside and below and is continuously curved from a vertical surface to a horizontal surface is concentrically fitted and fixed.

The mixed flow auxiliary fan 14 has substantially the same shape as the outer cutting corner of the tip end portion 13a of each main wing 13 on the concave arc-shaped outer peripheral surface of the body 15 substantially on the extension line in the axial direction of each main wing 13. A large number of arcuate auxiliary wings 16 of the same size are fixed so as to be orthogonal to each other at a predetermined interval in the circumferential direction. Each aileron 16
Does not cause air to flow obliquely outward along the concave arcuate curved surface of the body portion 15 and separate the circumferential velocity component in the rotational direction,
It is formed in the shape of a wing that efficiently flows.

An inner bell mouth 17 is concentrically arranged above the upper end of the body portion 15 in the figure at a predetermined interval to form a main suction port 17a. Inner bell mouth 1
Reference numeral 7 is a cylindrical body that expands upward in the drawing in a bell shape. The outer bell mouth 18 is concentrically arranged on the outer peripheral side of the inner bell mouth 17 with a required gap radially outward. The auxiliary suction port 18a constitutes an annular gap between the inner and outer bell mouths 17 and 18.

The outer bell mouth 18 is a cylindrical body that expands upward in the drawing in a bell shape, and like the inner bell mouth 17, is fixed to a fan casing (not shown) in which the multi-blade blower 11 is rotatably incorporated. It

As shown in FIG. 2, the outer bell mouth 18 has its inner end portion (lower end portion in the drawing) extended to the lateral side of the outer surface of the front end portion of the 16 rows of the auxiliary wings, with respect to the outer surface of the front end portion. Are opposed to each other with a small gap in the radial direction, and the facing portion has a function as a guide ring that controls air to flow obliquely along the blade surface of each auxiliary blade 16.

As shown in FIG. 2, the outer bell mouth 18 is formed so that the inflow cross-section area α and the outflow cross-section area β of the air into the mixed flow auxiliary fan 14 are substantially the same.
The blast efficiency is improved.

Next, the operation of this embodiment will be described.

When the substrate 12 is rotated around the axis by a fan motor (not shown), air is blown from the main air intake port 17a of the inner bell mouth 17 to the main wing 13 row as shown in FIG. While being sucked into the peripheral portion, it is sucked into the auxiliary blade 16 rows of the mixed flow auxiliary fan 14 from the auxiliary air suction port 18a between the inner and outer bell mouths 17 and 18 as shown by the small white arrow.

For this reason, the auxiliary blades 16 rows allow the suction air to flow obliquely outward with respect to the axis of the substrate 12 as indicated by the white small arrow in the figure, and the oblique flow of the outer bell mouth 18 at the lower end in the figure. The air is discharged from the gaps between the auxiliary wings 16 to the outside thereof by being guided by the section.

Further, the main wing 13 row discharges the intake air outward from the gap between the main wings 13 as shown by the large white arrow in the figure.

FIG. 3 shows a multi-blade blower 1 constructed in this way.
1 shows the P-Q characteristic A of No. 1 in comparison with the P-Q characteristic B of the conventional multi-blade blower 1 shown in FIG. 10. As shown in this P-Q diagram, the multi-blade blower 11 of the present embodiment is shown. The P-Q characteristic A of (1) significantly increases the blown air flow rate per unit time in the low pressure flow region as compared with the conventional example B in the low pressure flow region.

That is, in the multi-blade blower 11 of the present embodiment, the cross-flow auxiliary fan 14 is provided with the suction-side tip portion, which is reverse to the main air flow of each main blade 3, like the conventional multi-blade blower 1. Therefore, it is possible to greatly suppress the backflow at the suction-side tip portion, enhance the aerodynamic efficiency, and enhance the air blowing performance of the multiblade blower 11 as a whole.

Therefore, a high air-blowing performance can be obtained with a rotational driving force smaller than that of the conventional one, and noise can be reduced when the air-blowing amount is almost the same as that of the conventional example 1, and the flow rate is relatively low and high. A pressure blower can be provided.

FIG. 4 is a multi-blade blower 2 of the second embodiment of the present invention.
FIG. 5 is a partially cutaway perspective view of FIG. 1, and FIG. 5 is a longitudinal sectional view thereof. This multiblade blower 21 has an annular band plate-shaped guide ring 22 on the outer surface of the suction side tip of the 16 rows of auxiliary blades of the above embodiment. Is characterized in that the lower end of the outer bell mouth 23 in the figure is opposed to the upper end of the guide ring 22 with a slight gap therebetween.

The guide ring 22 controls air to flow obliquely along the blade surface of each auxiliary blade 16,
As shown in FIG. 4, the inflow cross-sectional area α0 and the outflow cross-sectional area β0 of the air into the mixed flow auxiliary fan 14 are formed to be substantially the same, thereby improving the blowing efficiency.

FIG. 6 is a schematic configuration diagram of the multi-blade blower 31 when the multi-blade blower 21 is rotatably incorporated in a spiral fan casing 32, and FIG. 7 is a plan sectional view thereof.
Reference numeral 33 in the figure denotes a fan motor that rotates by fixing a rotation shaft to a boss portion (not shown) of the substrate 12.

The multi-blade blower 31 is an improved fan casing 32 for reducing noise particularly in a low frequency range. That is, in the multi-blade blower 31, as shown in FIG. 7 or 8, a large number of small holes 34 are bored in the inner wall 32a of the fan casing 32, and the sound absorbing material 35 is brought into close contact with the inside of the inner wall 32a. A sound deadening space 36 is formed between the sound absorbing material 35 and the outer wall 32b.

In this multi-blade blower 31, the size of the sound deadening space 36, in particular, the length in the air flow direction indicated by the arrow in the figure,
The noise in the low frequency range can be reduced by selecting it so as to match the low frequency range to be silenced. The fan casing 32 can also be applied to the small fan casing 320 shown in FIG. Further, the multi-blade blower incorporated in the fan casings 32 and 320 may be the multi-blade blower shown in FIG.

FIG. 9 shows the multi-blade blower 31 with the main body case 4
2 shows a state in which a front panel 43 of, for example, a ceiling-embedded air conditioner 41 built in 2 is removed, and as described above, the air conditioner 41 has a multi-blade blower 31 with high blowing performance and low noise. Since this is incorporated, it is possible to improve air conditioning efficiency and reduce noise.

In the above embodiment, the main wing 13 is connected to the substrate 12
The case where the present invention is applied to a so-called multi-blade fan that is inclined forward with respect to the rotation direction of is described, but the present invention is not limited to this and may be applied to, for example, a turbo fan.

FIG. 11 shows an example in which the turbo fan 51 is incorporated as an indoor fan in an indoor unit 52 of an air conditioner such as a ceiling cassette type. The turbo fan 51 is attached to a rotary shaft 54 of a fan motor 53. A large number of arcuate plate-shaped main wings 13 are erected parallel to the axis of the base plate 12 on the base plates 12 to be joined, and are tilted rearward with respect to the rotation direction of the base plate 12 so that the air flow of the main wings 13 is increased. It is characterized in that the equal suction side tip portion is formed in the mixed flow auxiliary fan 14, and in FIG. 11, the same or corresponding portions as those in FIG. 1 are denoted by the same reference numerals.

The P-Q characteristic of the turbofan 51 thus constructed is as shown by the curve C in FIG. The fan characteristic curve D is remarkably increased. In FIG. 11, reference numeral 55 is an indoor heat exchanger that surrounds at least a part of the outer periphery of the turbofan 51, 56 is a suction grill, 57 is an outlet grill, and the white arrow in the figure indicates the direction of air flow.

[0047]

As described above, according to the first to sixth aspects of the present invention, conventionally, the tip end portion of each main wing on the suction side of the working fluid such as air, for example, 25 to 40% of the total length from the tip end. In the tip portion, the working fluid on the discharge side is flowing backward with respect to the flow of the portion other than the tip portion, which lowers the aerodynamic efficiency and lowers the blowing performance. Since each tip of the main blade is configured as an auxiliary fan that functions as a mixed flow fan, it is possible to suppress backflow at the tip of the main blade row and improve the air blowing performance at the tip of each main blade row, and thus to increase the number of blades. The blower performance of the blower as a whole can be improved.

Further, according to the second aspect of the present invention, since the inner bell mouth for guiding the working fluid such as air to be sucked in is provided on the inner peripheral side of the leading end of the main blade row, air and the like on the inner peripheral side of the leading end of the main blade row can be prevented. The suction efficiency can be increased, and thus the air blowing performance of the multiblade blower as a whole can be improved.

Further, an outer bell mouth which guides the working fluid so as to be sucked from the outer end side in the axial direction of the aileron, and an outer bell mouth which is formed integrally with the outer bell mouth to direct the flow of the sucked working fluid to the substrate axis. On the other hand, since it has a guide ring that guides outward in an oblique direction, it is possible to improve both suction efficiency and discharge efficiency of the working fluid to the auxiliary fan. For this reason, the blow performance of the auxiliary fan as a mixed flow fan can be improved, and thus the blow performance of the multi-blade blower as a whole can be improved.

Further, according to the third invention of the present application, the working fluid sucked from the axially outer end of the auxiliary blade row to the outer surface of the auxiliary blade row is caused to flow obliquely outward with respect to the substrate axis. Since the guide ring for guiding is fixed by being externally fitted, the air blow performance of the auxiliary fan as a mixed flow fan can be enhanced, and thus the air blow performance of the multi-blade blower as a whole can be improved.

Further, according to the fourth aspect of the present invention, since the inner bell mouth for guiding the working fluid to be sucked is provided on the inner peripheral side of the main blade row front end, the suction efficiency of the working fluid to the inner peripheral side of the main blade row front end is increased. Can be increased.

Further, since the outer bell mouth for guiding the working fluid to be sucked in is provided on the axially outer end side of the auxiliary blade,
The suction efficiency of the working fluid to the auxiliary fan can be improved. As a result, it is possible to improve the blowing performance of the multi-blade blower as a whole.

Further, according to the sixth aspect of the present invention, the guide ring is constructed so that the inflow cross-sectional area and the outflow cross-sectional area of the working fluid into the auxiliary fan are substantially the same, so that the blowing efficiency is improved. be able to.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a main part of an embodiment of a multiblade blower according to the present invention.

FIG. 2 is a vertical cross-sectional view of FIG.

FIG. 3 is a PQ diagram showing the PQ characteristics of the embodiment shown in FIG. 1 in comparison with those of the conventional example.

FIG. 4 is a partially cutaway perspective view of a main part of another embodiment of the multiblade blower according to the present invention.

5 is a vertical cross-sectional view of FIG.

FIG. 6 is a schematic configuration diagram of still another embodiment of the present invention.

FIG. 7 is a plan sectional view of FIG.

FIG. 8 is a plan sectional view of another embodiment of the present invention.

FIG. 9 is an exploded perspective view of an air conditioner incorporating the multiblade blower shown in FIG. 7 and the like.

FIG. 10 is a perspective view of a conventional multiblade blower.

FIG. 11 is a vertical cross-sectional view of another embodiment of the present invention.

12 is a PQ diagram of the indoor fan (turbo fan) shown in FIG.

[Explanation of symbols]

 11, 21, 31 Multi-blade blower 12 Substrate 13 Main wing 14 Mixed flow auxiliary fan 15 Body 16 Auxiliary wing 17 Inner bell mouth 17a Main air inlet 18,23 Outer bell mouth 18a Auxiliary air inlet 22 Guide ring 51 Turbo fan ( Indoor fan) 52 Indoor unit α, α0 Air inflow cross section β, β0 Air outflow cross section

Claims (6)

[Claims] 1. A substrate, which rotates about an axis, and a large number of main wings, which are annularly arranged on the substrate at predetermined intervals in the circumferential direction, are sucked from the inner peripheral side of the front end of the main blade row. In a multi-blade blower that discharges a working fluid to the outer peripheral side of the main blade row, the tip outer corner portion of each main blade is respectively an inwardly convex concave arc surface curved along an oblique direction with respect to the axis of the substrate. Then, the outer peripheral surface of each concave arc surface of these main blades is fitted and fixed to a cylindrical body that fits the concave arc surface, and the concave arc-shaped outer peripheral surface of this cylindrical body is provided with a predetermined interval in the circumferential direction. A multi-blade blower comprising a plurality of auxiliary blades, which is configured as an auxiliary fan that allows working fluid to flow obliquely outward with respect to the axis of the substrate. 2. An inner bell mouth that guides a working fluid to be sucked toward the inner peripheral side of the leading end of the main wing row, and an outer end in the axial direction of the aileron that is arranged outside the inner bell mouth at a predetermined interval. An outer bell mouth that guides the working fluid to be sucked from the side, and a guide ring that is integrally formed with the outer bell mouth and that guides the flow of the sucked working fluid outward in an oblique direction with respect to the substrate axis. The multiblade blower according to claim 1, further comprising: 3. A guide ring for guiding the working fluid sucked between the auxiliary blade rows so as to flow obliquely outward with respect to the axis of the substrate is fixed to the outer surface of the auxiliary blade rows. The multiblade blower according to claim 1, which is characterized in that. 4. An inner bell mouth that guides a working fluid to be sucked toward the inner peripheral side of the leading end of the main wing row, and an outer end in the axial direction of the aileron that is arranged outside the inner bell mouth at a predetermined interval. The outer wing mouth which guides so that a working fluid may be sucked in from the side, The multiblade fan of Claim 3 characterized by the above-mentioned. 5. The auxiliary fan has an axial length of each main blade of 1
The multi-blade blower according to claim 1, wherein the multi-blade blower is formed at a tip end portion corresponding to a length of 25 to 40 from the suction side tip end when 00 is set. 6. The guide ring is configured such that an inflow cross-sectional area of the working fluid into the auxiliary fan and an outflow cross-sectional area of the working fluid are substantially equal to each other. A multi-blade blower according to item.