JP2953049B2 - Cooling fan for vehicle alternator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention comprises a plurality of blades disposed around a bottom plate provided integrally with a rotor of a vehicle alternator, and rotates with the rotor. The present invention relates to a cooling fan for an AC generator for a vehicle, which blows cooling air through the cooling fan.

[Prior Art] Conventionally, in an automotive alternator equipped with this type of cooling fan, noise generated by the generator due to cooling air sent from the fan corresponds to the number of blades arranged around the fan. By arranging the blades at different pitches around the bottom plate to prevent noise from being concentrated on the noise component of a specific frequency and dispersing the noise due to cooling air over a wide frequency range, 2. Description of the Related Art Cooling fans that reduce the perceived noise are used.

[Problems to be Solved by the Invention] However, in such a cooling fan of an automotive alternator, since the blades are arranged at different pitches, the center of gravity of the cooling fan is deviated from the center. The cooling fan has to be provided eccentrically with respect to the rotor so that the center of gravity of the cooling fan is located at the center of the rotation axis.

This not only complicates the rotor assembly work,
Errors tend to occur in the amount and angle of eccentricity of the fan.

In addition, in the cooling fan used for the internal fan type vehicle AC generator, it is necessary to design the outer circumference of the fan to be smaller than the rotor so that the outer circumference does not protrude from the outer circumference of the rotor and come into contact with the generator frame. This caused the cooling air volume to decrease.

Therefore, the present invention is to provide a cooling fan of an automotive alternator in which blades are arranged at different pitches around a bottom plate, so that the center of the cooling fan can be provided without eccentricity with respect to the rotor. Made for the purpose.

Means for Solving the Problems According to the present invention made to achieve the above object, a bottom plate provided integrally with a rotor of a vehicular alternator, and disposed at different pitches around the bottom plate. A large number of blades, and a cooling fan for an automotive alternator formed by punching a plate into a required shape and then bending each of the blades, wherein the area of the blades arranged at a large pitch is reduced. The larger the area of the blades arranged at a small pitch, and at the edge of the bottom plate near the blades arranged at a large pitch, the vicinity of the blades arranged at a small pitch. The gist of the invention is a cooling fan for an AC generator for a vehicle, wherein the cooling fan is provided with an extended edge portion which is extended as compared with the edge of the bottom plate.

[Function] In the cooling fan of the automotive alternator of the present invention configured as described above, since the blades are arranged at different pitches around the bottom plate, the generator is generated by the cooling air sent from the fan. Noise is distributed over a wide frequency range. Further, since the cooling fan of the present invention is formed by punching a plate into a required shape and then bending the blade, the production is easy and the manufacturing cost is reduced.

In addition, the area of each blade formed by punching in this manner is such that the area of the blades arranged at a large pitch is larger than the area of the blades arranged at a small pitch. For this reason, where the pitch at which the blades are arranged is large, the mass per blade increases. Further, the edge of the bottom plate near the blades arranged at a large pitch is provided with an extended edge portion which is expanded as compared with the edge of the bottom plate near the blade arranged at a small pitch. The displacement of the center of gravity due to the difference in pitch is compensated for by the mass of these blades and the mass of the extended edge.

When the expanded edge is located radially outside the bottom plate, the centrifugal force acting on the expanded edge increases, so that the adjustment of the position of the center of gravity is further improved. When the extended edge is provided as a center-of-gravity position adjusting unit, the center-of-gravity position can be finely adjusted by cutting the center-of-gravity position adjusting unit. Further, each of the blades may be constituted by a first blade group arranged adjacently at a predetermined pitch and a second blade group arranged adjacently at a pitch larger than the pitch, In accordance with these blade groups, a difference may be given to the blade area, and the presence or absence of the extended edge may be set.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing a configuration of a cooling fan 1 of a vehicle alternator according to a first embodiment. The cooling fan 1 of this embodiment is used for an internal fan type vehicle AC generator in which a cooling fan is directly fixed to a side surface of a pole core constituting a rotor.

In the center of the bottom plate 3 welded to the pole core side surface of the vehicle alternator (not shown), a hole through which a rotating shaft is inserted and which engages with a member protruding from the pole core side surface to determine the fixing position of the cooling fan 1 is provided. The part 5 is drilled and the bottom plate 3
Are provided around the blades B1 to B10 for generating cooling air. Further, the bottom plate 3 near the blades B1 and B8 to B10 is provided with a center-of-gravity position adjusting unit 7 for finely adjusting the center-of-gravity position.

Here, blades B1 to B6 are blades adjacent to each other.
The blades B1 to B6 are arranged so that the pitch angles formed around the rotation center of the cooling fan 1 are substantially θ, and
B7 to B10 are arranged with a larger pitch angle.

On the other hand, the blades B1 to B10 are formed in predetermined sizes described below.

That is, as shown in the drawing, XY coordinates are created with the rotation center of the cooling fan 1 as the origin, and the coordinates of the center of gravity of each of the blades B1 to B10 are (X1, Y1) to (X10, Y10). The masses M1 to M10 of the blades B1 to B10 are The areas of the blades B1 to B10 are set so as to substantially satisfy the following equation. That is, the area of each of the blades B1 to B10 is set to be substantially proportional to the pitch angle between the adjacent blades B1 to B10.

For this reason, since the blades B1 to B6 are arranged with a substantially equal pitch angle θ, they are formed in substantially the same area, and the masses M1, M2, M3, M4, M5 and M6 have substantially the same value. But
The blades B7 to B10 have a pitch angle θ between the blades B1 to B6.
Since it is arranged with a larger pitch angle, it is rotated 90 ° and formed in a wider area as shown by the two-dot chain line, and the mass M7, M8, M9, M10 and the mass M1 ~ M6 The relationship of Mi (1 ≦ i ≦ 6) <M7, M8, M9, M10 is established between them.

Next, the cooling fan 1 pierces each of the blades B1 to B10 perpendicularly to the bottom plate 3 after punching the blades B1 to B10 from one iron plate into a shape developed in the same plane as the bottom plate 3. The center of gravity of the cooling fan 1 and the center of rotation, that is, the origin of the XY coordinates shown in FIG. Adjustments are made.

In other words, the coordinates of the adjusted center of gravity of the bottom plate are (Xa, Ya),
When the mass of the bottom plate 3 is Ma, The center-of-gravity position adjusting unit 7 is cut so as to satisfy the following equation exactly.

In the cooling fan 1 of the present embodiment configured as described above, the blades B1 to B10 are arranged at different pitch angles around the bottom plate 3 so that the cooling air generates the vehicle AC generator. Noise that is perceived can be dispersed over a wide frequency range, and the perceived noise can be reduced.

Also, since the areas of the blades B1 to B10 are individually set so that the center of gravity of the cooling fan 1 matches the center of rotation,
Unlike the conventional cooling fan in which each blade is simply arranged at a different pitch around the bottom plate, there is no need to provide the blade eccentrically with respect to the rotor, and therefore, the assembly work of the rotor is simplified, and The balance adjustment after the rotor is assembled can also be omitted. Further, it is not necessary to form the cooling fan 1 with a smaller diameter than the rotor of the automotive alternator, and a sufficient amount of air can be obtained.

Further, in the cooling fan 1 of this embodiment, the center of gravity
Since the fine adjustment is performed by cutting the center of rotation, the center of gravity of the cooling fan 1 and the rotation center can be more accurately matched.

Next, FIG. 2 (A) is a front view showing a configuration of a cooling fan 21 of a vehicle AC generator according to a reference example of the present invention, and FIG. 2 (B) is an explanatory view showing a configuration of a blade portion thereof. It is.
Note that the cooling fan 21 of the present reference example is not formed by punching a plate into a required shape as in the present invention, and its production is not easy as compared with the case where the present invention is applied, so that the manufacturing cost is high. . That is, the cooling fan 21 is a cooling fan of the external fan type vehicle AC generator fixed to the rotating shaft from outside the frame of the vehicle AC generator (not shown), and is integrally formed of synthetic resin. .

In the cooling fan 21, in the center of the bottom plate 23, a hole 25 through which a rotating shaft is inserted is bored, and around that, blades B11 to B20 that generate cooling air are arranged at different pitches. I have. As shown in FIG. 2 (B), each blade B1
1 to B20 are all formed in the same shape, but their thicknesses are individually set as shown in FIG. 2 (A), calculated in the same manner as in the first embodiment, and each has a predetermined mass. Thus, the center of gravity of the cooling fan 21 and the center of rotation are matched.

For this reason, the noise generated by the automotive alternator due to the cooling air from the cooling fan 21 can be dispersed over a wide frequency range, so that the perceived noise can be reduced and the rotor assembling operation can be simplified. be able to. More preferably, the balance adjustment after assembling the rotor can also be omitted.

[Effects of the Invention] As described above in detail, in the cooling fan of the automotive alternator according to the present invention, the noise generated by the generator due to the cooling air from the fan is dispersed in a wide frequency range, and the noise perceived by the user is felt. Not only can be reduced, but also the center of gravity of the fan is located at the center of the bottom plate, so that the center of the cooling fan can be provided so as to coincide with the center of the rotor.
The rotor assembly operation can be simplified. Moreover,
In the present invention, since the position of the center of gravity is adjusted not only by the area of the blade but also by the expanded edge provided on the edge of the bottom plate, the blade area that can be used is restricted from the viewpoint of reducing noise and securing the air flow. Even in this case, a good balance can be secured for the entire fan. Further, since the cooling fan of the present invention is formed by punching a plate into a required shape and then bending a blade, the creation is facilitated.
The manufacturing cost can be reduced favorably.

[Brief description of the drawings]

FIG. 1 is a front view showing a configuration of a cooling fan of a vehicle alternator according to a first embodiment, and FIG. 2 (A) shows a configuration of a cooling fan of a vehicle alternator according to a reference example of the present invention. FIG. 2 (B) is a front view, and FIG. 2 (B) is an explanatory view showing the configuration of the blade portion. 1,21 cooling fan, 3,23 bottom plate B1-B20 blade

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 9/00-9/28

Claims (4)

(57) [Claims] A bottom plate provided integrally with a rotor of the automotive alternator; and a number of blades disposed around the bottom plate at different pitches. A cooling fan for an automotive alternator formed by bending each of the blades, wherein an area of the blades arranged at a large pitch is formed larger than an area of the blades arranged at a small pitch. In addition, the edge of the bottom plate in the vicinity of the blades arranged at a large pitch is provided with an extended edge portion that is extended as compared with the edge of the bottom plate in the vicinity of the blades arranged at a small pitch. A cooling fan for an AC generator for a vehicle, comprising: 2. The cooling fan of an automotive alternator according to claim 1, wherein said extended edge portion is located radially outward of said bottom plate. 3. A cooling fan for an automotive alternator according to claim 1, wherein said extended edge portion is provided as a center-of-gravity position adjusting portion (7). 4. A first blade group (B1 to B6) arranged adjacently at a predetermined pitch, and a second blade group arranged adjacently at a pitch larger than the pitch. The cooling fan according to any one of claims 1 to 3, wherein (B7 to B10) is configured.