JPH083169Y2 - Cooling fan structure for vehicle alternator - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan structure for a vehicle alternator mounted on a vehicle such as an automobile.

[0002]

[Prior Art and Problems to be Solved by the Invention] In general,
In this type of vehicle AC generator (alternator), a cooling fan having a plurality of blades protruding from it is integrally attached to the side surface of a rotor core that is rotatably supported by a case bracket, and the rotor core is rotated. The cooling air that has flowed in from the inlet opening on the side surface of the case bracket based on the air blowing operation of the cooling fan that flows through the cooling air flow passage that faces the outer diameter to cool the coil end portion of the stator coil wound around the stator core. Then, there is a so-called inner blade type in which the flow is made to flow out from the outlet on the outer peripheral surface of the case bracket.

However, in the conventional case, FIG. 8 and FIG.
As shown in FIG. 5, the blade body 15 has a substantially flat shape and protrudes toward the side surface of the case bracket.
Inlet 14 with the outer diameter of the case opened on the side of the case bracket
Since the diameter is larger than the outer diameter of the case, the inflow efficiency of the cooling air from the inflow port 14 is poor, and a part of the cooling air captured by the blade body escapes in the side direction of the case bracket to the inner peripheral surface. It will flow out from the outlet as it is,
As a result, there is a problem that the cooling efficiency by the cooling air is reduced.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention was devised with the object of providing a cooling fan structure for a vehicle alternator capable of eliminating these drawbacks. At the side of the rotor core that is rotatably supported by the case bracket, a cooling fan with a plurality of blades protruding from the side of the case bracket facing the inflow port is integrally assembled to rotate the rotor core. The cooling air that has flowed in from the inlet due to the air blowing action of the cooling fan that accompanies the cooling fan flows through the cooling air flow path that is oriented in the outer diameter direction to cool the coil end portion of the stator coil that is wound around the stator core. In an automotive alternator configured to flow out from the outer peripheral surface, the outer diameter of the blade body and the outer diameter of the inflow port are set to be equal, and The tip of the diameter is bent toward the advancing side in the rotational direction with a gap between it and the blade on the advancing side in the rotational direction of the cooling fan, and the cooling air flowing from the inlet is supplemented and guided to the cooling air flow path. The cooling air guide body is formed.

According to the present invention, it is possible to reliably prevent the captured cooling air from escaping to the side surface of the case bracket and to improve the cooling efficiency. .

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 is an AC generator for a vehicle, and the generator 1 includes a rotor core 3 press-fitted and fixed to a core shaft 2, a coil bobbin 4 installed in the rotor core 3, and a rotor wound around the coil bobbin 4. The coil 5, the stator core 6 around which the stator coil 6a is wound, the brush 8 housed in the brush holder 7, the slip ring 9 on which the brush 8 slides elastically, and both side surfaces of the rotor core 3 are integrally assembled. The cooling fan 10, which will be described later, and the rectifying unit 11 that rectifies the generated alternating current are the same as those in the related art, and the power generation using these members is the same. The outer shell of the machine 1 is constituted by a case bracket 12 having a two-case case structure including a front case bracket and a rear case bracket.

The cooling fan 10 includes a base plate 10a integrally assembled with the rotor core 3 and a plurality of blades formed by cutting and raising the blade-corresponding portions of the base plate 10a toward the side surface 12a of the case bracket. The blade body 13 is constituted by the blade body 13, and the tip edge portion 13a of the blade body 13 facing the case bracket side surface 12a is bent toward the forward side in the fan rotation direction. A wind guide is configured. That is, the cooling air flowing from the inflow port 14 of the case bracket side surface 12a based on the wind operation of the cooling fan 10 accompanying the rotation of the rotor core 3 is directed in the outer diameter direction to cool the coil end portion of the stator coil 6a. The cooling air that has flowed in at this time flows out from the outlet 14a of the outer peripheral surface 12b of the case bracket via the air flow path. It is captured so as not to escape in the direction of the case bracket side surface 12a and is guided to the cooling air flow path that faces the outer diameter direction.

In the embodiment of the present invention constructed as described above, the side surface of the case bracket 1 is driven by the air blowing operation of the cooling fan 10 accompanying the rotation of the rotor core 3 as described above.
The cooling air that has flowed in from the inflow port 14 of 2a flows out from the outflow port 14a of the outer peripheral surface 12b of the case bracket via the cooling air flow path that faces the outer diameter direction, but faces the side surface 12a of the case bracket of the blade body 13. Leading edge 13a
Is bent toward the forward side in the fan rotation direction to form a cooling air guide body, and the inflowing cooling air escapes in the direction of the case bracket side surface 12a as in the conventional case and flows out along the inner peripheral surface as it is. It is avoided that the cooling air flow path passes through the coil end portion of the stator coil 6a, so that the stator coil 6a is efficiently cooled. Therefore, the cooling efficiency of the stator coil 6a can be surely improved, and the cooling efficiency is poor, so that the temperature of the stator coil 6a rises too much and the power generation efficiency does not deteriorate. It can be a high-output generator 1.

By the way, in carrying out the present invention, a more specific study is made on the relationship between the height (protruding height in the axial direction) H of the blade body 13 and the bending length L of the tip edge portion 13a. It was According to this, the ratio of the protruding height H of the blade body 13 to the bending length L of the tip edge portion 13a (L /
It has been found that it is preferable that H) is set to be in the range of approximately 0.05 ≦ L / H ≦ 0.3. That is, in FIG. 5, a cooling fan formed by pressing an iron plate is adopted, and the L / H ratio is changed in a state in which the rotation speed of the generator is unified as described later, and the stator coil at this time is changed. 6a temperature change (generator speed 300
It is shown that the measurement was performed for the relationship of (unification to 0 rotation) and the change of bending stress acting on the base end portion of the blade body 13 (unification of rotation speed of generator to 2700 rotations per minute).
As is clear from this result, regarding the effect of decreasing the temperature, the temperature of the stator coil 6a gradually decreases as the L / H ratio increases from 0 (the state in which there is no bent portion), and the temperature decreases to about 0.05. It was observed that a temperature decrease of as much as 10 degrees was observed in the ratio of 0, and the temperature decreased as the ratio further increased, but the effect of the temperature decrease became saturated at the ratio of approximately 0.4.

On the other hand, with respect to the blade body, bending stress acts on the root portion due to the bent tip edge portion, which causes a problem of deformation of the cooling fan. Observing it from the measurement results of FIG. 5, the bending stress acting on the base end portion of the blade body 13 was 20 at the stage when L / H was about 0.3, compared with that without a bent portion. %, Which is disadvantageous in terms of strength. From these viewpoints, the blade body 1
It can be said that the ratio of the height H of 3 and the bending length L of the tip edge portion 13a is preferably selected in the range of 0.05 ≦ L / H ≦ 0.3.

Further, in carrying out the present invention, there is room for studying the relationship between the size of the inlet 14 and the size of the blade body 13 in order to improve the efficiency of the cooling air.
Therefore, the relationship between the inflow port 14, the outer diameter, and the outer diameter of the blade body 13 was examined. Here, regarding the inner diameter of the inflow port 14,
This is because there is almost no room for consideration because it is roughly determined by the bearing 2a that supports the core shaft 2, but there is room for consideration regarding the outer diameter of the inflow port 14. In this examination, the ratio of the height H of the blade body 13 to the bending length L of the tip edge portion 13a, that is, L / H is set to 0.2, and the flow from the axis O is taken. The distance to the outer diameter of the inlet 14 is X, the distance from the axis O to the outer diameter of the blade 13 is Y, and the stator coil 6a when the outer diameter of the inlet 14 is variously changed with respect to the blade 13 The temperature change was observed.
In order to confirm the effectiveness of the invention of the present application, the same examination was performed for a conventional one in which there is no bent cooling air guide for the tip edge portion 13a. The result is shown in FIG.

According to FIG. 6, the tip edge portion 13 of the blade body 13 is shown.
The bent a is clearly effective in lowering the temperature of the stator coil 6a in any state as compared with the conventional one in which it is not, and the effectiveness of the present invention is confirmed. In the case where 13a is bent, the temperature of the stator coil 6a is most decreased by X.
/Y=1.0, that is, the outer diameter X of the inflow port 14 and the outer diameter Y of the blade body 13 are equal to each other, whereas the conventional cooling guide body does not have X / Y = 0. It is observed that 9 is the lowest value. This is because the tip edge portion of the blade body 13 is bent, so that the cooling air flowing in from the inflow port 14 is efficiently captured by the bent tip portion and reliably delivered to the outflow port 14a side. It is presumed that the present invention has additional capacity for supplemental delivery function of cooling air, and makes the outlet 14 larger than the conventional one so that a large amount of cooling air can flow in. Since a large amount of cooling air that has flowed in can be efficiently captured and delivered to the outlet side, the cooling performance of the stator coil 6a can be further improved. If the outer diameter X of the inflow port 14 is larger than the outer diameter Y of the blade body 13, it is presumed that the cooling air escapes from the larger portion and the cooling efficiency is reduced.

[0013]

In summary, since the present invention is constructed as described above, the tip edge of the blade body bent toward the advancing side in the rotation direction serves as a cooling air guide body for rotating the rotor core. The cooling airflow that cools the coil ends of the stator core by efficiently capturing the cooling air that has flowed in from the inlet opening on the side of the case bracket based on the airflow operation of the cooling fan so that it does not escape toward the side of the case bracket. I will guide you to the road. As a result, the outside diameter of the inlet does not have to be smaller than the outside diameter of the blade body because part of the cooling air that has flowed in escapes in the side direction of the case bracket as in the conventional case, and it is the same as the outside diameter of the blade body. The size can be set to increase the inflow of cooling air, and the cooling efficiency can be improved to reduce the temperature of the stator coil, resulting in a high-output and high-quality generator. be able to.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of a generator.

FIG. 2 is a front view of a cooling fan.

3A and 3B are a side view and a plan view of a blade body, respectively.

FIG. 4 (A) is an operation explanatory view showing a cooling air flow path, (B).
FIG. 6 is an operation explanatory view showing a cooling air flow path in a preferable inflow state.

FIG. 5 shows a ratio (L / H) between a protruding height H of the blade body and a bending length L of the tip edge portion, a temperature change of the stator coil, and a change of bending stress acting on the base end portion of the blade body. It is a graph which shows a relationship.

FIG. 6 is a ratio of the outer diameter X of the inlet and the outer diameter Y of the blade body (X /
It is a graph figure which shows the relationship between Y) and the temperature change of a stator coil.

FIG. 7 is a front view of a front case bracket.

FIG. 8 is a front view of a cooling fan showing a conventional example.

FIG. 9 is an operation explanatory view showing a cooling air flow path in a conventional example.

[Explanation of symbols]

 1 Generator 3 Rotor Core 6 Stator Core 6a Stator Coil 10 Cooling Fan 12 Case Bracket 13 Blade Body

Claims (1)

[Scope of utility model registration request] 1. A rotor core having a plurality of blades protruding from the side surface of a rotor core that is rotatably supported by a case bracket so as to face an inlet opening formed on the side surface of the case bracket. The cooling air that has flowed in from the inflow port based on the air blowing action of the cooling fan accompanying the rotation of the In a vehicle AC generator configured to flow from the outer peripheral surface of a case bracket, the outer diameters of the blade body and the inlet from the rotor core axis are set to be equal, and the outer diameter tip edge portion of the blade body is The cooling fan is bent toward the advancing side in the rotating direction while leaving a gap with the blade on the advancing side in the rotating direction, and the cooling air flowing from the inlet is supplemented and guided to the cooling air flow path. A cooling fan structure in an automotive alternator, characterized in that a cooling air guide body is formed.