JP2001304183A - Cooling fan with tapered hub - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling fan with a tapered hub manufactuable at low cost in which a molding mold becomes a simple shape by molding it to two members and assembling them. SOLUTION: The cooling fan 10A with a tapered hub is constituted by a cooling fan body 1 in which a plurality of blades 3 are provided on a periphery of cylindrical part of the cylindrical hub 2; and a hub cover 4A of tapered shape formed separately from the cooling fan body 1. A cut-in portion 4c is formed on at least one of a neighborhood of the hub 2 of the blade 3 or the hub cover 4A. The cooling fan body 1 and the hub cover 4A are engaged and integrally formed at the cut-in portion 4c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan having a tapered hub used for an automobile engine or the like.

[0002]

2. Description of the Related Art Engines used in automobiles and the like, particularly diesel engines, have been increasing their output,
In addition, measures against noise have been improved not only in the quietness of the engine itself, but also in the direction of shutting off the engine from the outside by employing a sound insulation cover or the like that covers the engine.

As a result, while the heat load on the engine increases and the amount of generated heat increases, the heat radiating area decreases and the heat radiation deteriorates. Therefore, it is not an exaggeration to say that the engine cooling performance affects the feasibility of the vehicle. .

If the engine cooling performance cannot be ensured, the engine will overheat. As a measure to prevent this overheating, there is a method of increasing the performance of the radiator to increase the cooling effect against cooling water, but there is a limit to the improvement of the cooling effect of the radiator,
It has been considered to improve the performance of the cooling fan attached to the engine, and to respond by increasing the ventilation volume.

The cooling fan of the engine is connected to the crankshaft of the engine via a fluid fan clutch or the like, or in a small car or the like, as shown in FIG. 6, a crank pulley 41 and a fan pulley 42 of a crankshaft 40. Are connected by a fan belt 43 and driven by rotation of a crankshaft 40.

The cooling fan 10 is usually provided with a radiator
The radiator 30 is provided at the rear of the radiator 30 in order to facilitate the heat exchange in the radiator 30.
Flow around 20 to ventilate the engine room.

Since this cooling fan is basically driven by the crankshaft of the engine, the state of the engine when the cooling is required most, the vehicle speed at that time, the engine speed derived therefrom, and the vehicle speed The fan characteristics are determined so as to maximize the performance as a cooling fan in consideration of the amount of air naturally introduced into the engine room, which is closely related to the speed, and the like.

For example, in an example of a large vehicle in which the cooling performance of the cooling fan is most required to be improved, the vehicle speed on the assumption of climbing a hill while towing a trailer is 4 at best.
It is about 0 km / h.

The contribution rate of the traveling wind is 2-3 for passenger cars.
It is said that it is less than 20% for commercial vehicles, and the amount of air blown by the cooling fan itself greatly contributes to the cooling effect.

An axial fan is often used as the cooling fan. When the hub 2 is formed in a cylindrical shape as shown in FIGS. 7 and 8, air flowing from the front is used. In A, the meridional flow flows backward along the cylindrical axis C of the hub 2 (the rotation axis of the cooling fan 1).

However, in the flow of the air A along the cylindrical axis C, the engine body 20 is positioned rearward (downstream side: direction D).
Is disposed, the air A blown by the cooling fan 1 collides with the engine body 20 behind the cooling fan 1 and stagnates, and the back pressure is increased. As a result, the cooling efficiency becomes poor. In particular, it becomes an important problem in idling operation during a stop when traveling wind effects cannot be expected, or in extremely low-speed traveling.

In order to cope with this problem, the meridional flow is inclined with respect to the rotation axis C of the cooling fan, that is, spreads radially on the rear side, flows out, and smoothly flows around the engine body. 9 and 10, a cooling fan 11 having a hub 2X formed in a tapered shape whose rear side expands in diameter has been proposed.

A tapered hub 2 which promotes this mixed flow
In the cooling fan 11 having X, the air A flowing from the front of the engine is spread radially and flows rearward, whereby the flow can be improved, and the result of improving the cooling efficiency is obtained.

[0014]

However, the cooling fan 11 having the tapered hub 2X has a problem that the manufacturing cost is increased.

That is, these engine cooling fans are manufactured by integrally molding a blade and a hub with a synthetic resin or the like. However, in the case of the cooling fan 11 having the cylindrical hub 2X, the cooling fan is usually vertically (Or front and back) It is a mold for molding divided into two parts, and it is drawn up and down (or front and back) and formed.

On the other hand, in the cooling fan 11 having the tapered hub 2X, the hub 2X has the tapered portion 2Xb in addition to the cylindrical portion 2Xa, and the tapered portion 2Xb is attached because the blade 3 is obliquely attached. Since an undercut portion occurs in a portion surrounded by the 2Xb and the blade 3, the mold cannot be removed with a two-part mold. Therefore, a mold is divided for each blade, and the mold is formed by extracting the mold in the radial direction.

As a result, a large number of divided molds are required, and the manufacturing cost is several times the manufacturing cost of the cooling fan 1 having the ordinary cylindrical hub 2.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. The object of the present invention is to provide a structure in which a molding die is formed into a simple structure by forming it into two members and assembling it.
An object of the present invention is to provide a cooling fan having a tapered hub that can be manufactured at low cost.

[0019]

SUMMARY OF THE INVENTION A cooling fan having a tapered hub for achieving the above object has the following features.
A cooling fan main body in which a plurality of blades are radially provided around a cylindrical portion of a cylindrical hub, and a tapered hub cover formed separately from the cooling fan main body. At least one of the cutouts is formed, and the cooling fan body and the hub cover are fitted and integrated at the cutouts.

This notch may be formed only on the hub cover side, may be formed only on the blade side, or may be formed on both the hub cover side and the blade side. It is also possible to form them on both sides so as to make them smaller in size and to be advantageous in strength.

The hub cover may be made of the same material as the cooling fan body or a different material.
Further, it may be formed of a material such as a synthetic resin, or may be formed by cutting a light metal material such as an aluminum alloy by pressing or the like.

The shape of the blade is preferably a diagonal flow design, but is not limited to this.

According to the cooling fan having the tapered hub having the above configuration, the hub cover is fitted into the cooling fan body having the cylindrical hub that can be formed by a two-piece mold, so that the tapered hub can be easily formed. Since a cooling fan having a hub can be manufactured, a molding die is simplified and manufacturing costs are reduced.

That is, a cooling fan main body composed of a cylindrical hub and a blade is integrally formed by upper and lower molds, and a hub cover formed separately is fitted into the cooling fan main body, and attached by screwing or bonding. Since a cooling fan having a tapered hub can be formed, it can be manufactured at low cost.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 5, the cooling fan having a tapered hub according to the embodiment of the present invention is provided with a cylindrical hub 2 and radially arranged around the cylindrical portion of the cylindrical hub 2. And a plurality of blades 3 and 3B. The cooling fan bodies 1 and 1B include tapered hub covers 4A and 4B.

The cooling fan bodies 1 and 1B having the cylindrical hub 2 are made of a light metal such as a synthetic resin or an aluminum alloy integrally with the blades 3 and 3B. It can be molded with the same two-part mold as the fan.

As shown in FIG. 1, the hub cover 4A is formed in a tapered shape having a small diameter at the front and a large diameter at the rear, and has a fixing portion 4a and a screw hole 4b. It is formed by providing a notch 4c that fits with the notch. The fixing portion 4 a is in contact with the outer peripheral surface of the cylindrical hub 2 to secure the fixing to the cooling fan main body 1.

The hub cover 4A may be made of the same material as the cooling fan body 1, or may be made of another material. In addition, since it may be a molded product of a synthetic resin or the like and the structure is relatively simple, it can be manufactured by stamping out an aluminum alloy plate material or the like with a press.

Then, as shown in FIG. 1, the hub cover 4A is fitted into the cooling fan main body 1 from the front of the cooling fan main body 1, that is, from the upstream side, while the notch 4c is fitted to the blade 3, and the hub cover 4A is screwed in. Secure with screws.
For this fixing, a known method such as bonding or welding can be used other than screwing.

Thus, a cooling fan 10A having a tapered hub as shown in FIG. 2 is formed.

As shown in FIGS. 3 and 4, notches 3c, 4c are formed on both the blade 3B side and the hub cover 4B side, and these notches 3c, 4c are fitted to each other, as shown in FIG. As shown, a cooling fan 10B having a tapered hub can also be formed. This configuration is advantageous in terms of strength because the size of the cuts 3c and 4c is smaller.

Although not shown, a configuration in which a notch is provided only on the blade side can be adopted. The hub covers 4A and 4B are formed of a cooling fan body 1 having a cylindrical hub 2.
May be attached from behind.

The taper inclination angle α of the hub covers 4A and 4B is preferably 15 to 45 degrees.

The dimensions of the hub covers 4A and 4B do not depend only on the diameter of the cooling fan bodies 1 and 1B, but also vary depending on the diameter of the hub 2 and the blade thickness of the blades 3 and 3B. Specific examples of dimensions are as follows.
The outer diameter of 3B is φ720 mm, and the outer diameter of cylindrical hub 2 is φ3.
In the case of 00 mm and the height of the hub 2 being 80 mm, the outer diameter of the hub covers 4A and 4B is φ400 mm to φ450 mm, and the height is 80 mm to 170 mm.

According to the cooling fans 10A and 10B having the tapered hubs having the above-described configurations, the hub covers 4A and 4B are fitted to the cooling fans 1 and 1B having the cylindrical hubs that can be formed by two-piece molds. Thus, the cooling fans 10A and 10B having the tapered hub can be easily manufactured.

[0037]

As described above, according to the cooling fan having the tapered hub according to the present invention, the cooling fan body having the cylindrical hub that can be formed by the two-piece mold is provided with the tapered hub. By fitting the hub cover,
Since a cooling fan having a tapered hub can be easily manufactured, a molding die can be simplified and manufacturing costs can be reduced.

Further, even for a cooling fan having an existing cylindrical hub, a cooling fan having a tapered hub can be easily obtained simply by providing a tapered hub cover. Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view including a partial cross section showing an assembly of a cooling fan having a tapered hub according to an embodiment of the present invention.

FIG. 2 is a perspective view including a partial cross section showing a cooling fan having a tapered hub after assembly in FIG. 1;

FIG. 3 is a plan view showing a hub cover according to another embodiment of the present invention.

FIG. 4 is a plan view showing a cooling fan main body to which the hub cover of FIG. 3 is assembled.

5 is a plan view showing a cooling fan having a tapered hub formed by assembling the hub cover of FIG. 3 and the cooling fan main body of FIG. 4;

FIG. 6 is a perspective view of an engine room showing a state in which a cooling fan is mounted.

FIG. 7 is a perspective view including a cross section showing a cooling fan having a cylindrical hub of the prior art.

FIG. 8 is a plan view showing the cooling fan of FIG. 7;

FIG. 9 is a perspective view including a cross section showing a cooling fan having a tapered hub of the prior art.

FIG. 10 is a plan view showing a cooling fan having the tapered hub of FIG. 9;

[Explanation of symbols]

1, 1B Cooling fan body 2 Cylindrical hub 3, 3B Blade 4A, 4B Hub cover 10A, 10B Cooling fan having tapered hub

Claims (1)

[Claims] 1. A cooling fan main body having a plurality of blades radially provided around a cylindrical portion of a cylindrical hub, and a tapered hub cover formed separately from the cooling fan main body. A cooling fan having a tapered hub, wherein a cut portion is formed in the vicinity or at least one of the hub cover, and the cooling fan main body and the hub cover are fitted and integrated at the cut portion.