JP2000130399A - Cooling fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly improve a cooling operation by guiding cooling air from an impeller to a blow-out side with little draft resistance and without generating any vortex flows by a guiding groove formed along the flow of ventilation air in an inner peripheral surface surrounding the impeller so as to increase the amount of ventilation air and increasing a surface area by the guiding groove. SOLUTION: This cooling fan includes one or more helical cooling air guiding grooves 9 formed along the flow of ventilation air in the inner peripheral surface of an impeller housing room 7 in a fan casing 4. In this case cooling air from an impeller is guided to a blow-out side by the cooling air guiding grooves 9 without generating any vortex flows and by reducing draft resistance and a cooling operation is greatly improved by increasing the amount of ventilation air and a surface area by the guiding grooves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling fan used for cooling a heat-generating component such as an MPU in a personal computer and other electronic devices.

[0002]

2. Description of the Related Art Generally, an MPU 1 is used as a functional component in a small electronic device such as a multifunctional, high-performance personal computer as shown in FIG. 7, but this MPU 1 is a local high heat source. Therefore, the heat of the MPU 1 is guided to the fan casing 4 also serving as a heat sink of the cooling fan 3 by the aluminum plate 2, and the fan casing 4 is cooled by the wind generated by the impeller 5 that is rotationally driven by the motor. As a result, the MPU 1 generates the heat. Heat is released to ensure the safety of the equipment. Reference numeral 6 in the drawing denotes a printed circuit board provided with related electronic components.

The cooling fan 3 is, as shown in FIG.
The fan casing 4 also serves as a heat sink,
It has an impeller storage chamber 7 having one side as an air suction port and the other side as a discharge port. The impeller storage chamber 7 is provided with a motor unit (not shown) and an impeller 5 driven to rotate by the motor unit. Thus, the inner peripheral surface 8 of the impeller storage chamber 7 is a smooth surface.

[0004]

The cooling air generated by the rotation of the impeller 5 hits the inner peripheral surface 8 of the impeller storage chamber 7 of the fan casing 3 of the conventional cooling fan. The force is a strong pressing force of a three-dimensional vector which is a combination of a centrifugal force in the horizontal direction, a suction force in the vertical direction, and a rotational force in the horizontal direction with respect to the impeller surface. In the configuration in which the cooling air is guided to the outlet only by the pressure, the pressing force becomes a large ventilation resistance, and the cooling air hitting the inner peripheral surface 8 rebounds to generate a vortex, thereby reducing the amount of air flow and cooling. In some cases, it is difficult to obtain a sufficient amount of ventilation, and an effective cooling operation cannot be performed.

For this reason, for example, when the heat generation temperature of the MPU 1 increases due to the operating frequency, sufficient cooling cannot be obtained, and the MPU 1 and its peripheral parts deteriorate due to heat.
Otherwise, there is a risk of thermal destruction.

[0006] The present invention has been made in view of the above problems, and has as its object to provide a cooling fan exhibiting an extremely effective cooling action.

[0007]

According to the present invention, an impeller is provided in an impeller storage chamber of a fan casing, and an impeller is provided on an inner peripheral surface of the impeller storage chamber along a flow of ventilation. Alternatively, a cooling fan having a cooling air guide groove more than that is formed.

According to the present invention, not only the heat of the heat-generating component is guided to the fan casing to dissipate heat and cool the fan, but also the cooling air generated by the impeller follows the flow of ventilation along the inner peripheral surface surrounding the impeller. By the formed guide groove,
The airflow is guided to the blow-out side with reduced ventilation resistance without generating a vortex, and the cooling action is further increased by an increase in the airflow and an increase in the surface area by the guide groove.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a fan casing having an impeller storage chamber which also serves as a heat sink and has an air suction port on one side and a discharge port on the other side. A motor unit and an impeller rotatably driven by the motor unit in the room, wherein one or more cooling air guide grooves are formed on an inner peripheral surface of the impeller storage chamber along a flow of ventilation. The cooling fan is guided to the blowing side with reduced ventilation resistance without generating a vortex, and has an effect of further increasing the cooling action.

According to a second aspect of the present invention, in the cooling fan according to the first aspect, the cooling air guide groove is a spiral groove, and the cooling air guide groove follows a flow of the cooling air generated by rotation of the impeller. Since the cooling air guide groove is provided, the cooling air is guided to the blow-out side with reduced ventilation resistance, and has an effect that a vortex does not occur and a cooling effect is further increased.

According to a third aspect of the present invention, in the cooling fan according to the first aspect, the cooling air guide groove is a linear groove, and the cooling air guide groove follows a flow of the cooling air generated by the rotation of the impeller. Since the cooling air guide groove is formed, the air is guided to the blow-out side with reduced ventilation resistance, and there is an effect that vortex does not occur and the cooling effect is further increased.

According to a fourth aspect of the present invention, in the cooling fan according to any one of the first to third aspects, the depth of the cooling air guide groove is gradually increased from the start end to the end. The cooling air guide groove follows the flow of the cooling air generated by the rotation of the impeller,
In addition, since the depth of the groove gradually increases, the groove is guided to the blow-out side with reduced ventilation resistance, and further, there is an effect that vortex does not occur and the cooling action is further increased.

According to a fifth aspect of the present invention, in the cooling fan according to any one of the first to third aspects, the cooling air guide groove is formed so that the width of the groove gradually increases from the start end to the end. In the same manner as described above, the cooling air guide groove follows the flow of the cooling air generated by the rotation of the impeller, and since the width of the groove gradually increases, the ventilation resistance is reduced on the blowing side. It is guided and does not generate a vortex, and has the effect of further increasing the cooling action.

According to a sixth aspect of the present invention, in the cooling fan according to the first aspect, the fan casing is generally formed in a rectangular parallelepiped, and the inner peripheral surface of the impeller storage chamber is cylindrical. The thickness of the inner peripheral surface of the impeller storage chamber is not uniform, and the cooling air guide groove is formed only in a portion of the fan casing corresponding to the inner peripheral surface thick portion of the impeller storage chamber. In order to reduce the size of the fan casing, it is possible to form the cooling air guide groove even if the fan casing is made small and the wall pressure between the peripheral surface of the impeller housing chamber and the outside of the fan casing becomes thin.

An embodiment of a cooling fan according to the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a perspective view of a cooling fan according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view of the same cooling fan without an impeller. In the drawings, the same components as those of the conventional technology shown in FIGS. 6 and 7 are denoted by the same reference numerals as those of the conventional technology.

As shown in FIGS. 1 and 2, the fan casing 4 of the cooling fan 3 is made of aluminum die-casting having good heat conductivity, is formed in a square shape and flattened as a whole, and also serves as a heat sink. The fan casing 4 is formed with an impeller storage chamber 7 having one side as an air suction port and the other side as a blowout port. The impeller storage chamber 7 has a motor (not shown) and a rotation by the motor. A driving impeller 5 is provided.

The first embodiment is characterized in that the inner peripheral surface 8 of the impeller storage chamber 7 in the fan casing 4
In this configuration, a plurality of cooling air guide grooves 9 formed of spiral grooves along the flow of cooling air generated by rotation of the impeller 5 are formed.
In the first embodiment, a plurality of the cooling air guide grooves 9 are provided, but a single cooling air guide groove 9 may be provided.

It is needless to say that the cooling fan 3 is used while being thermally coupled to a heat-generating component such as the MPU 1 as shown in FIG.

Here, the heat generated by the heat-generating components such as the MPU is conducted to the fan casing 4 of the cooling fan 3, and is radiated by the heat sink function of the fan casing 4 and forcedly cooled by the cooling air generated by the rotation of the impeller 5.

More specifically, the cooling air generated by the rotation of the impeller 5 strongly hits the inner peripheral surface 8 of the impeller storage chamber 7 surrounding the impeller 5 by centrifugal force, and generates a ventilation resistance and a vortex on the inner peripheral surface 8. However, the cooling air is guided by the cooling air guide groove 9 formed of a spiral groove on the inner peripheral surface 8 so as to follow the flow of the cooling air to the blowing side with reduced ventilation resistance. Does not occur, the amount of cooling air flow increases, and the cooling air guide groove 9 further increases the surface area, thereby further increasing the cooling effect.

(Embodiment 2) FIG. 3 is a developed view of an inner peripheral surface of an impeller storage chamber in a cooling fan according to Embodiment 2 of the present invention.

In the cooling fan according to the second embodiment, as shown in FIG. 2, the cooling air guide grooves 9 on the inner peripheral surface 8 of the impeller housing chamber 7 in the fan casing 4 are linearly grooved along the flow of the cooling air. 9a.

According to this structure, the groove does not exactly follow the flow of the cooling air unlike the spiral groove, but has a long groove similar to the flow of the cooling air, and reduces the ventilation resistance to the side where the cooling air is blown out. It guides and does not generate a vortex, the amount of cooling air flowing therethrough increases, and the cooling action becomes large.

(Embodiment 3) FIG. 4 is a cross-sectional view of a cooling air guide groove of an impeller storage chamber in a cooling fan according to Embodiment 3 of the present invention.

In the cooling fan according to the third embodiment, as shown in FIG. 4, the depth of the cooling air guide groove 9 in the inner peripheral surface 8 of the impeller housing chamber 7 in the fan casing 4 is gradually increased from the start end to the end. It has a special feature.

Here, the cooling air is compressed as it approaches the end of the cooling air guide groove 9 and the pressure increases. In the third embodiment, the depth of the cooling air gradually increases from the start end to the end of the cooling air guide groove 9. Since the pressure of the cooling air is prevented from gradually increasing, that is, the ventilation resistance is gradually reduced and the cooling air is effectively guided while increasing the amount of cooling air,
The cooling action is even greater.

(Embodiment 4) FIG. 5 is a developed view of an inner peripheral surface of an impeller storage chamber in a cooling fan according to Embodiment 4 of the present invention.

In the cooling fan according to the fourth embodiment, as shown in FIG. 5, the width of the cooling air guide groove 9 in the inner peripheral surface 8 of the impeller housing chamber 7 in the fan casing 4 is gradually increased from the start end to the end. It has the characteristic.

Here, the cooling air is compressed as it approaches the end of the cooling air guide groove 9, and the pressure increases. In the fourth embodiment, the width of the cooling air is gradually increased from the start end to the end. Therefore, the pressure of the cooling air is prevented from gradually increasing, that is, the ventilation resistance is gradually reduced and the cooling air is effectively guided while increasing the ventilation amount,
The cooling action is even greater.

(Embodiment 5) FIG. 6 is a plan view of a fan casing of a cooling fan according to Embodiment 5 of the present invention.

As shown in FIG. 6, the cooling fan according to the fifth embodiment has a fan casing 4 formed in a flat and rectangular shape as a whole, and has four corners of the fan casing in the thick portion of the inner peripheral surface of the impeller housing chamber 7. The cooling air guide groove 9 is formed only in a portion corresponding to the above.

According to this configuration, the size of the fan casing is reduced in order to reduce the size of the cooling fan, and the cooling air guide groove 9 is formed even when the wall pressure between the peripheral surface of the impeller housing chamber and the outside of the fan casing decreases. The cooling air can be guided to the blow-out side with reduced ventilation resistance, and the vortex does not occur, the amount of the cooling air flowing increases, and the cooling effect can be increased. .

In each of the above embodiments, the fan casing is made of aluminum die-cast, but may be made of another metal material. Further, the fan casing may be directly joined to a heat-generating component such as an MPU.

[0034]

As is apparent from the above description, according to the present invention, not only the heat of the heat-generating component is guided to the fan casing to radiate and cool the fan, but also the cooling air generated by the impeller is released from the impeller storage chamber. The cooling air guide groove formed on the inner peripheral surface of the cooling air guide along the flow of air is guided to the blowout side with reduced ventilation resistance, so that the amount of airflow increases, that no vortex is generated, and that the cooling air guide groove As a result, a cooling fan having a larger cooling effect is realized, and the effect is great.

[Brief description of the drawings]

FIG. 1 is a perspective view of a cooling fan according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the cooling fan without the impeller of the cooling fan.

FIG. 3 is a developed view of an inner peripheral surface of an impeller storage chamber in the cooling fan according to the second embodiment of the present invention.

FIG. 4 is a sectional view of a cooling air guide groove of an impeller storage chamber in a cooling fan according to a third embodiment of the present invention.

FIG. 5 is a development view of an inner peripheral surface of an impeller storage chamber in the cooling fan according to the fourth embodiment of the present invention.

FIG. 6 is a plan view of a fan casing in a cooling fan according to a fifth embodiment of the present invention.

FIG. 7 is a perspective view of a cooling device using a cooling fan.

FIG. 8 is a perspective view of a conventional cooling fan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 MPU 2 Aluminum plate 3 Cooling fan 4 Fan casing 5 Impeller 6 Printed circuit board 7 Impeller storage room 8 Inner peripheral surface 9 Cooling air guide groove 9a Straight groove

Claims (6)

[Claims] A fan casing, which also serves as a heat sink, has an impeller storage chamber having one side as an air suction port and the other side as a blowout port, and a motor unit and an impeller rotationally driven by the motor unit in the impeller storage room. A cooling fan, wherein the cooling fan is provided with one or more cooling air guide grooves formed along the flow of ventilation on an inner peripheral surface of the impeller storage chamber. 2. The cooling fan according to claim 1, wherein the cooling air guide groove is a spiral groove. 3. The cooling fan according to claim 1, wherein the cooling air guide groove is a straight groove. 4. The cooling fan according to claim 1, wherein the cooling air guide groove is formed so that the depth of the groove gradually increases from the start end to the end. 5. The cooling fan according to claim 1, wherein the cooling air guide groove is formed so that the width of the groove gradually increases from the start end to the end. 6. The cooling fan according to claim 1, wherein the cooling air guide groove is formed only in a portion corresponding to the thickened portion on the inner peripheral surface of the impeller storage chamber of the fan casing.