JPS631036Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a multi-blade fan device provided in an intake unit of an automobile air conditioner.

(Prior art) Intake unit 1 of an automotive air conditioner
has a multi-blade fan device 5 in which a multi-blade fan 3 driven by a motor 2 is provided in a fan scroll 4 as shown in FIG.
An inside air circulation port 6 into which the circulation flow into the vehicle interior flows is located at the top of the
, an outside air inlet 7 through which outside air flows in, and an intake door 8 that selects air from the inside air circulation port 6 or the outside air inlet 7 by rotating the multi-blade fan 3.
It has an inside/outside air switching box 9 having the following.

Note that the air blown out from the intake unit 1 is appropriately cooled or heated to a predetermined temperature, and then is distributed to appropriate locations within the vehicle interior.

The multi-blade fan 3, which blows out the suction air by centrifugal force while turning the suction air at right angles to the air suction direction, has conventionally had a plurality of blades 10 arranged in an annular shape as shown in FIG. This blade 10
One end (suction side) 10a is held by a retaining ring 11 from the outer periphery, and the other end 10b is held by a boss part 12.
The entire body is molded from synthetic resin to reduce weight.

(Problem that the invention aims to solve) However, since this resin needs to have excellent heat resistance and sufficient strength and rigidity, polycarbonate is generally used, but this resin is quite expensive. Therefore, in order to reduce product costs, other inexpensive resins must be used.

However, cheap resins do not have sufficient strength and heat resistance, so a reinforcing ring 13 is provided in the center of the fan blade 10 as shown by the dashed line in FIG. A rib 14 is formed on the lower surface of the ring 11, and the retaining ring 11
Various reinforcing measures must be taken, such as increasing the holding power of the

However, if this is done, there is a risk that not only the mold for fan molding will be complicated, but also the manufacturing process will be complicated.

Further, when the blade 10 crosses the nose portion (not shown) of the fan scroll 4 and the cross-sectional shape of the gap is rectangular (it is rectangular if the blade 10 is straight), the blade 10 is Since the air is compressed all at once to the lower end, and the blades 10 pass one after another across this nose section, a so-called whine sound called po is generated at this nose section.

This invention was made in view of the above-mentioned problems, and it has excellent heat resistance even when molded with inexpensive materials.
It is an object of the present invention to provide a multi-blade fan which has a structure with no problem in terms of strength and also has excellent performance such as improved air compressibility and reduced fan noise.

[Structure of the invention] (Means for solving the problem) In order to achieve the above object, the present invention holds one end of a plurality of blades arranged in an annular manner with a retaining ring, and holds the other end with a boss. In a multi-blade fan device in which a multi-blade fan attached to a fan scroll is provided in a fan scroll, the blade, the retaining ring, and the boss portion are integrally molded with resin, and there is a gap between the inner wall of the fan scroll and the outer surface of the blade. An auxiliary blade is formed on the outer surface of the blade so as to protrude radially outward from the retaining ring so that the gap gradually increases from the suction side of the multi-blade fan to the boss portion side. It is characterized by:

(Function) In this way, in this invention, the fan blade is provided with an auxiliary blade, and the gap between a part of the fan blade and the inner wall of the fan scroll on the suction side is narrowed. The air compressibility is improved, and the gap gradually widens from the suction side to the boss side, which reduces noise when the blade crosses the nose of the fan scroll.
Moreover, it becomes a multi-blade fan device with excellent rigidity.

(Example) An example of the present invention will be described below with reference to the drawings.

FIG. 4 is a sectional view showing an example of a multi-blade fan device according to the present invention, and the same members as those shown in FIGS. 1 to 3 are given the same reference numerals.

This multi-blade fan device 20 has a multi-blade fan 21 provided within a fan scroll 4.

As shown in FIG. 5A, this multi-blade fan 21 has a plurality of blades 22 arranged in an annular manner, with suction side ends 22a held by a retaining ring 23, and boss side ends 22b fixed to a boss 24. It is something.

This boss portion 24 protrudes into the interior of the fan 21 as shown in FIG. 4, and a rotating shaft 25 of the fan motor M is attached to this protruding portion with a nut 26.

In particular, in the present invention, the blade 22, retaining ring 23, and boss portion 24 are integrally molded from an inexpensive resin (for example, acetal, etc.), and
The retaining ring 23 is designed such that the gap between the inner wall 4a of the fan scroll 4 and the outer surface 22c of the blade 22 gradually widens from the suction side of the multi-blade fan 21 to the boss side. An auxiliary blade 27 is formed that projects outward in the radial direction.

In order to form such a multi-blade fan 21 with resin, as shown in FIG. 5B, by placing the boss portion 24 downward and cutting it out in the direction of the arrow, the auxiliary blade 27 having the shape as described above is formed. Even if it is, it can be molded without any problem.

If this auxiliary blade 27 is formed radially outward of the retaining ring 23, there is a risk that the entire fan will be thermally deformed into a drum shape when the fan rotates in a thermal atmosphere, but this thermal deformation can be counteracted. Since reinforcement is formed, heat deformation resistance is improved, and the auxiliary blade 27 contributes to an improvement in rigidity.

In particular, as is clear from FIG. 4, this multi-blade fan device 20 uses the auxiliary blades 27 to
Since the gap l between the inner wall 4a of the fan scroll 4 and the outer surface 22c of the blade 22 gradually widens from the suction side of the multi-blade fan 21 to the boss side, this When the blade fan 21 is rotated to compress air between it and the inner wall 4a of the fan scroll 4, the static pressure at the time of suction is increased, and air compressibility is improved.

Furthermore, if the cross-sectional shape of the gap part is made into a shape other than a rectangle such as a trapezoid, the gap l will not be uniform, and the air will not be compressed uniformly from the upper end to the lower end of the blade 22, resulting in the above-mentioned squealing noise. Noise generation can be prevented or reduced.

In the embodiment described above, the auxiliary blade 27 is formed from one end of the fan blade 22 to the other end, but the present invention is not limited to this in any way, and the auxiliary blade 27 is formed as shown in FIG. blade 2
7 may be formed only at the outermost position of the retaining ring 23.

[Effects of the invention] As described above, according to the invention, the blade, the retaining ring, and the boss are integrally molded with resin, and the gap between the inner wall of the fan scroll and the outer surface of the blade is smaller than that of the multi-blade fan. Since the auxiliary blades are formed on the outer surface of the blades so as to gradually become wider from the suction side to the boss side, it is possible to obtain a fan having a structure with excellent heat deformation resistance and rigidity. On the air suction side,
Since the gap between the fan and the scroll becomes smaller, the fan's air compressibility improves, and if the auxiliary blades are made longer, noise can also be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an intake unit of an automobile air conditioner, Fig. 2 is a perspective view of a conventional multi-blade fan, Fig. 3 is an enlarged view of the main parts of a conventional multi-blade fan,
Fig. 4 is a sectional view showing an embodiment of the present invention, Fig. 5A is an enlarged perspective view showing main parts of the embodiment, and Fig. 5B
is a schematic cross-sectional view showing the die cutting direction of the same multi-blade fan,
FIG. 6 is a perspective view of main parts showing another embodiment of the present invention. 4... Fan scroll, 4a... Inner wall, 20
...Multi-blade fan device, 21...Multi-blade fan, 22
...Fan blade, 22a...One end, 22b
...Other end portion, 22c...Outer surface, 23...Retaining ring, 24...Boss portion, 27...Auxiliary blade,
l...Gap.

Claims (1)

[Scope of utility model registration request] A multi-blade fan device in which a multi-blade fan is provided in a fan scroll, in which one end portion of a plurality of blades arranged in an annular manner is held by a retaining ring and the other end portion is attached to a boss portion, the blades;
The retaining ring and the boss portion are integrally molded with resin, and the gap between the inner wall of the fan scroll and the outer surface of the blade gradually increases from the suction side of the multi-blade fan to the boss portion side. In the multi-blade fan device, an auxiliary blade is formed on an outer surface of the blade and protrudes radially outward from the retaining ring.