JP2002317796A - Propeller fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propeller fan easy to be assembled and having hollow vane. SOLUTION: This propeller fan is made of plastic and integrally formed of a cylindrical boss 4 provided with a through hole 10 for insertion of a rotary shaft at the center thereof, several vanes 1 provided with a cylindrical boss 8 having a screw hole at the center thereof in a bottom part of a recessed part 6 provided in one side of the vane and divided in the circumferential part of the center shaft 4 with an equal space at the base end thereof, and a cover plate 3 to be fitted on the vane 1, while covering the recessed part 6, and having a tip connected to a tip of the vane 1 through a hinge 2 and provided with an insertion hole 9 corresponding to the screw hole 7. The hinge 2 as a connection part for connecting the vane 1 and the cover plate 3 to each other is formed into a linear shape at the predetermined thickness, and the cover plate 3 is folded in reference with the longitudinal direction of the hinge 2, and the cover plate 3 is fixed to the vane 1 by two screws 5 passed through the insertion hole 9 of the cover plate 3 and screwed to the screw hole 7 provided in the boss 8 of the vane 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propeller fan, and more particularly, to a propeller fan having a hollow inside a blade.

[0002]

2. Description of the Related Art Conventionally, as shown in a side view of FIG. 3A and a front view of FIG. 3B, a propeller fan has a plurality of blades 80 made of plastic at respective base ends 8.
1 is formed integrally with the circumference of a cylindrical boss 82, and the boss 82 has a through hole 83 through which a rotating shaft (not shown) of a motor for rotating a propeller fan is inserted. It was a structure prepared for. In order to efficiently move air, each of the blades 80 has been devised in various shapes such as by bending the blades 80 themselves. Generally feather 8
It is known that a turbulent flow is reduced by making the cross section of 0 a thick wing shape, thereby improving energy efficiency and reducing noise. For this reason, there are many conventional techniques in which the cross section of the blade 80 is formed in a thick wing shape or the inside is hollowed by lamination.

However, as described above, the propeller fan is integrally formed of plastic, and when the cross section of the blade 80 is formed into a thick wing shape, the amount of plastic resin used increases and the weight of the entire blade 80 increases. Therefore, it is necessary to employ a motor having a large rotational torque at the time of starting, which results in an increase in cost. Further, in the prior art in which the inside is hollowed by laminating, the work of bonding the laminating surfaces with an adhesive or joining by welding is troublesome, and the number of working steps is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a propeller fan which is easy to assemble and has a hollow blade inside.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a boss having a through hole through which a rotating shaft is inserted, a concave portion on one side, and a base end having the boss. A plurality of blades arranged at equal intervals on the outer peripheral portion of the blade, a cover plate that covers the recess and is fitted to the blade, and that forms the recess in a hollow shape, and a tip end of the cover plate and the blade. It comprises a hinge to be connected, and comprises fixing means for fixing the blade and the cover plate. The blade, the hinge, the cover plate and the boss are integrally formed of synthetic resin.

[0005] The fixing means is erected from the bottom of the recess, a second boss having a screw hole at the center, an insertion hole provided in the cover plate, corresponding to the screw hole, Into the screw hole.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a propeller fan according to the present invention will be described in detail with reference to the drawings. 1 (A) is a front view showing one embodiment of a propeller fan according to the present invention before assembling, and FIG. 1 (B) is a sectional view of a side surface after assembling. FIG. 2 is a cross-sectional view of a main part of FIG.
FIG. 4B is a cross-sectional view taken along the line A-A ′, and FIG. The propeller fan, as shown in FIG.
, Hinge 2, cover plate 3, and cylindrical boss 4 are integrally formed of plastic. Further, a fixing portion for fixing the blade 1 and the cover plate 3 is composed of a screw 5, a boss 8 as a second boss provided on the blade 1, and an insertion hole 9 provided on the cover plate 3. ing. The boss 4 is, as shown in FIG.
The base end of each of the plurality of blades 1 is arranged at equal intervals on the circumferential portion, and has a through hole 10 through which a rotating shaft (not shown) of a motor for rotating a propeller fan is inserted. In addition, two columnar bosses 8 having screw holes 7 at the center are erected from the bottom of a concave portion 6 in which one side of the blade 1 is formed in a concave shape. This blade 1 is shown in FIG.
As shown in the cross-sectional view of FIG. 1, the blade has a thick wing shape, and is formed thick in the rotation direction and thin in the opposite direction. Further, the front portion of the blade 1 in the rotation direction (the right end in FIG. 2B) does not have the recess 6. This is to ensure the strength of the blade 1 and to arrange the position of the center of gravity of the blade 1 in the rotation direction to achieve stability during rotation.

On the other hand, as shown in FIG.
This is a structure that covers the recess 6 and fits on the blade 1. The tip of the cover plate 3 is connected to the tip of the blade 1 by the hinge 2, and insertion holes 9 corresponding to the screw holes 7 are formed at two places on the cover plate 3. Have. The cover plate 3 is inserted through the insertion hole 9 and the boss 8 of the blade 1 is
Are fixed to the blade 1 by two screws 5 screwed into the screw holes 7. The height of the boss 8 is the same as the thickness of the recess 6, and has a structure in which the cover plate 3 is supported from inside the blade 1. As described above, the parts other than the screw 5 for fixing the cover plate 3 are integrally formed of plastic, and the hinge 2 is also formed of plastic. Therefore, a hinge 2 which is a connecting portion between the blade 1 and the cover plate 3 is formed in a straight line with a predetermined thickness, and the cover plate 3 is folded back on the basis of the longitudinal direction of the hinge 2 and fitted to the blade 1, When fixed with the above-mentioned screw 5, the concave portion 6 becomes a hollow portion.

As described above, the blade 1 and the cover plate 3 are integrally formed of plastic and are folded back by the hinge 2 to reduce the number of parts and eliminate the need for positioning the blade 1 and the cover plate 3. A hollow propeller fan that can be easily assembled can be provided. Further, by providing the boss 8 inside the concave portion 6, not only can the cover plate 3 be fixed to the blade 1 but also when the propeller fan is rotating at high speed.
The shape of the cover plate 3 can be maintained without losing the wind pressure.

[0009]

As described above, according to the propeller fan according to the present invention, the boss having the through hole through which the rotating shaft is inserted, the concave portion on one side, and the base end having the outer periphery of the boss. Consists of a plurality of blades arranged at equal intervals on the part, a cover plate that covers the recess and fits with the blade and forms a hollow recess, and a hinge that connects the tips of the cover plate and the blade. And fixing means for fixing the blade and the cover plate, and by integrally molding the blade, the hinge, the cover plate, and the boss with synthetic resin, the number of parts is reduced, and the connection between the blade and the cover plate is reduced. No alignment is required, and the propeller fan can be easily assembled. By providing the boss inside the recess, not only can the cover plate be fixed to the blade, but also the shape of the cover plate can be maintained without losing the wind pressure even when the propeller fan is rotating at high speed.

[Brief description of the drawings]

FIG. 1A is a front view showing one embodiment of a propeller fan according to the present invention before assembling, and FIG. 1B is a sectional view of a side surface after assembling.

FIG. 2 is a cross-sectional view of a main part of FIG.
FIG. 5B is a cross-sectional view taken along the line A ′, and FIG.

3A is a side view showing a conventional propeller fan, FIG.
(B) is a front view.

[Explanation of symbols]

 Reference Signs List 1 blade 2 hinge 3 lid plate 4 boss 5 screw 6 recess 7 screw hole 8 boss 9 insertion hole 10 through hole

Claims (2)

[Claims] 1. A boss having a through hole through which a rotation shaft is inserted, and a plurality of blades having a recess on one side and having base ends disposed at equal intervals on an outer peripheral portion of the boss. A cover plate that covers the recess and is fitted to the blade to form the recess in a hollow shape, and a hinge that connects the cover plate and the tip of the blade, connects the blade and the cover plate. A propeller fan, comprising: fixing means for fixing, wherein the blade, the hinge, the cover plate, and the boss are integrally formed of a synthetic resin. 2. The fixing means according to claim 1, wherein said fixing means is provided upright from a bottom of said concave portion, said second boss having a screw hole as a center, and an insertion hole provided in said lid plate and corresponding to said screw hole. The propeller fan according to claim 1, further comprising a screw inserted through the insertion hole and screwed into the screw hole.