JP2005337118A - cooling fan - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling fan with excellent reliability, practical use and productivity capable of flowing air along a fin part and effectively performing exhaustion from an exhaust port by changing a shape of the fin part so as to adjust to a direction that different air flows at left and right sides of a fan part, having excellent heat radiation efficiency, capable of reducing air passage resistance in a downstream part of air-blowing, blowing a large amount of cooling air and performing smooth exhaustion. <P>SOLUTION: The cooling fan is provided with a casing part 2 having an exhaust port 3 formed on one side surface; the air passage communicated with the exhaust port 3 and formed to an approximately circular shape; a fan part 5 arranged in the air passage; a cover part 9; a suction port 9a provided on the cover part 9; and a plurality of fin parts 8 provided in parallel such that a clearance of an end at at least the exhaust port 3 side is gradually increased from the upstream side of air-blowing toward the downstream side of air-blowing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooling fan that cools heating elements such as a microprocessing unit (hereinafter abbreviated as MPU) in a housing of an electronic device such as a personal computer.

  Products that use MPUs and peripheral ICs, such as personal computers and information terminals, are increasing in information processing speed and arithmetic processing speed year by year in order to provide a user-friendly environment, and accordingly MPUs and peripheral ICs are also faster. It is becoming large-scale and high-speed that operates with a large clock. In addition, the amount of generated heat increases in proportion to the speeding up of the MPU.

  At present, in order to stabilize the operation of the MPU, the heat generated by the operation of the MPU is generally radiated and cooled by combining heat radiating components such as a heat sink, a fan with a heat sink, and a heat pipe. Various inventions have been made.

  A practical cooling fan is composed of a heat sink portion thermally bonded to the MPU, and a fan motor that sends air to the heat sink portion to cool it. A material having good thermal conductivity is used for the heat sink, and generally a material such as aluminum, aluminum alloy, or copper is preferably used. The system is such that the heat generated by the MPU is diffused by the heat sink made of these materials having good thermal conductivity, and the heat generated by the MPU is dissipated by the cooling air blown by the fan motor to forcibly cool the heat generated by the MPU. .

  However, since notebook PCs and portable terminals are becoming more space-saving year by year, parts must be placed in a limited space, and the MPU generates heat to make the heat dissipation unit more compact. There is a need for a fin shape with excellent heat dissipation efficiency that can dissipate heat more effectively.

  For example, Patent Document 1 discloses a “cooling device for a heating element having a fin cross-sectional shape that extends along the direction of the flow of air flowing through a blower passage”.

  Further, Patent Document 2 states that “the MPU cooling fan motor integrated heat sink device blows air in one direction and exhausts it from the housing, so that it can serve as MPU cooling and the exhaust fan motor for the housing. A heat sink device "is disclosed.

Patent Document 3 states that “the gap between the outer periphery of the impeller and the inner peripheral surface of the fan housing recess gradually increases toward the downstream portion of the blower, and between the inner periphery of the air suction port of the casing cover and the outer periphery of the impeller boss portion. A fan-integrated cooling device is disclosed in which the gap is gradually reduced toward the air blowing downstream portion, and a reflux prevention rib is formed between the air outlet of the fan casing and the air blowing upstream portion.
JP 2000-332177 A JP-A-8-321571 JP 2000-104697 A

  However, the above conventional techniques have the following problems.

  In this type of conventional cooling fan, the cross-sectional shape of the fin is a blade shape extending along the direction of air flow, thereby reducing the air resistance when blowing air toward the fin and reducing the air volume. It is intended to prevent heat dissipation efficiency and suppress turbulence and maintain a quiet environment with low noise, but since the fins are arranged in a straight line in parallel, There was a problem that it was impossible to deal with different air flows, exhaust could not be performed effectively from the exhaust port, and heat dissipation efficiency and practicality were lacking.

  In this type of conventional cooling fan, the outer wall portion is a spiral casing structure, the air passage is enlarged from the spiral winding start portion toward the opening according to the rotation direction of the fan, and the circular shape varies depending on the position on the air passage. Arc-shaped fins are arranged to efficiently guide the wind, but the fins near the exhaust port are arranged in parallel and perpendicular to the exhaust port. However, there was a problem that the heat dissipation efficiency was lowered.

  Further, since the exhaust port is narrow, sufficient exhaust heat cannot be obtained, and there is a problem that it cannot cope with the heat generation of the MPU whose speed is evolving year by year.

  This type of conventional cooling fan is sufficiently ventilated by being arranged eccentrically in the fan housing recess so that the gap between the outer periphery of the impeller and the inner peripheral surface of the fan housing recess gradually increases toward the air blowing downstream portion. The fan efficiency is improved and the fan efficiency is improved. However, since the fin shape, especially the mounting angle, has not been sufficiently studied, different air flows on the left and right sides of the fan can be smoothly routed to the exhaust port. It was impossible to guide, and there was a problem that the air flow rate and heat dissipation efficiency were reduced.

  Moreover, since the fin arrange | positioned in the exhaust-port vicinity was small, it had the subject that sufficient heat dissipation effect was not acquired.

  The present invention solves the above-described conventional problems, and by changing the shape of the fin portion in accordance with the direction of air flow, which differs between the left and right sides of the fan portion, air can flow along the fin portion, Can be effectively exhausted from, excellent in reliability, practicality, productivity, and by forming the radius of the air passage so as to gradually increase from the upstream side to the downstream side in the rotational direction, An object of the present invention is to provide a cooling fan excellent in heat radiation efficiency that can reduce the air path resistance in the downstream portion of the air flow, can blow a large amount of cooling air, and can perform smooth exhaust.

  In order to solve the above-described problems, a cooling fan of the present invention is formed on a substrate portion, a peripheral wall portion surrounding the outer periphery of the substrate portion and standing on the surface of the substrate portion, and one side surface of the peripheral wall portion. A casing portion having an exhaust port; an air passage formed in a substantially superior arc shape in communication with the exhaust port inside the casing portion; a motor portion disposed in the air passage; and the motor portion A fan portion having a plurality of blades radially disposed on the outer periphery of the housing portion, and the substrate portion on the inner front surface portion of the casing portion. The fan portion is arranged between the fan portion and the exhaust port. A plurality of plate-shaped fin portions; a cover portion that is covered on the upper surface of the peripheral wall portion of the casing portion; and an air intake port that is formed to penetrate the cover portion so as to face the fan portion. And at least the end portions on the exhaust port side of the plurality of fin portions arranged side by side Septum has a structure that is formed so as to increase gradually from the air upstream to the blower downstream side.

As a result, the flow of air that is blown by the fan section and passes through the fin section becomes smooth, the heat dissipation effect can be enhanced, and the flow of air with different angles depending on the location can be reliably guided toward the exhaust port. Therefore, it is possible to provide a cooling fan that is capable of performing effective exhaustion and has excellent heat dissipation efficiency, practicality, and reliability.

  As described above, according to the cooling fan of the present invention, the following advantageous effects can be obtained.

  According to the first aspect of the present invention, the interval between at least the exhaust port side end portions of the plurality of fin portions arranged in parallel is gradually increased from the air blowing upstream side toward the air blowing downstream side. As a result, the angle formed by the fin portion and the opening end surface of the exhaust port can be gradually decreased from the upstream side of the air flow toward the downstream side of the air flow. It can flow smoothly along the fin part, can efficiently exchange heat with heat transferred from the heating element such as MPU to the fin part, and can be exhausted from the exhaust port. A cooling fan can be provided.

  According to the second aspect of the present invention, in addition to the effect of the first aspect, the end on the exhaust port side of the plurality of fin portions arranged from the first on the upstream side of the blower to the nth on the downstream side of the blower is provided. Since the angle formed by the opening portion and the opening end surface of the exhaust port is formed so as to gradually decrease by a certain angle from the upstream side of the air flow toward the downstream side of the air flow, the angle of air blown with the rotation of the fan unit The heat that can flow smoothly along the fin part, can efficiently exchange heat with the heat transferred from the heating element such as MPU to the fin part, and can exhaust heat from the exhaust port An efficient cooling fan can be provided.

  Since the angle formed between the end on the exhaust port side of the plurality of fins from the first on the upstream side of the blower to the nth on the downstream side of the blower and the open end surface of the exhaust port is defined. Even when the sizes of the parts, fan parts, fin parts, etc. are different, it is possible to provide a cooling fan excellent in design workability and productivity that can easily design the number and shape of the fin parts.

  According to the third aspect of the invention, in addition to the effect of the first or second aspect, the distance from the outer periphery of the fan portion to the inner peripheral wall surface of the air passage is gradually increased in the rotational direction from the upstream side to the downstream side. By increasing the air flow resistance at the downstream portion of the air flow, the cooling air with a large air volume can be blown, and the heat transferred from the heating element such as the MPU to the fin portion is cooled with the cooling air from the fan portion and the efficiency. Therefore, it is possible to provide a cooling fan with excellent heat dissipation efficiency that can exchange heat and exhaust heat from the exhaust port.

  By gradually increasing the distance between the outer periphery of the fan section and the inner peripheral wall surface of the air passage from the upstream side of the air flow to the downstream side of the air flow in the rotational direction, pressure fluctuation does not occur inside the air passage, and smooth Therefore, it is possible to provide a cooling fan excellent in low noise performance that can blow cooling air, can prevent generation of vortex and turbulence, and can reduce noise.

According to invention of Claim 4, in addition to the effect of any one of Claims 1 thru | or 3, from the air inflow start point which is a lower end part of the ventilation upstream of a wind path, it is the fan part of a ventilation downstream. With respect to the inner wall surface radius R ₀ of the air path up to the horizontal axis passing through the center, the inner wall surface radius R _j of the air path for every 45 ° rotation to the blower downstream side with respect to the rotation center of the fan portion is Since it increases with the radius increase amount ΔR and has a relationship of R _j = R ₀ + j × ΔR (where j is an integer from 1 to 4), the inner wall surface radius R _j of the air passage is increased at every fixed angle. It is possible to reliably increase the width of the air passage from the upstream side of the air flow to the downstream side of the air flow, and it is excellent in workability and productivity, and the air passage resistance in the air downstream portion can be reduced. It is possible to blow cooling air with a large air flow with respect to the heat generation element such as MPU and the fin portion. It is possible to provide a cooling fan with excellent heat dissipation efficiency that can efficiently exchange heat between the heat transferred to the cooling air and the cooling air.

  According to the fifth aspect of the invention, in addition to the effect of the fourth aspect, the fan portion is disposed so that the center of the minimum radius of the inner wall surface of the air passage matches the rotation center of the fan portion. The fan blades do not interfere with the inner wall surface of the air passage, prevent damage to the fan portion, and are highly reliable, increasing the width of the air passage from the upstream side to the downstream side. Therefore, it is possible to provide a cooling fan excellent in heat dissipation efficiency that can reduce the air path resistance in the air blowing downstream portion and can blow a large amount of cooling air.

  In the cooling fan, the air flow in the air passage and the fin portion can be made smooth without increasing the number of parts by a simple design change, and an increase in air passage resistance can be prevented. Optimize the shape of the air passage and the arrangement of the fins for the purpose of providing a cooling fan with excellent reliability, practicality, and productivity that can secure the air volume and reliably improve the heat dissipation efficiency. It was realized.

  A first invention made to solve the above problems includes a substrate portion, a peripheral wall portion that surrounds the outer periphery of the substrate portion and is erected on the surface of the substrate portion, and an exhaust port formed on one side surface of the peripheral wall portion. , A casing portion that communicates with the exhaust port inside the casing portion, is formed in a substantially arcuate shape, a motor portion disposed in the air passage, and radially disposed on the outer periphery of the motor portion A plurality of blades, a plurality of plate-like fin portions standing on the surface of the substrate portion on the inner front surface of the casing portion and arranged in parallel between the fan portion and the exhaust port, and the casing portion At least an exhaust port side of a plurality of fins arranged side by side with a cover portion that is covered on the upper surface of the peripheral wall portion and an intake port that is formed to penetrate the cover portion so as to face the fan portion Is formed so that the interval between the end portions gradually increases from the upstream side to the downstream side. Has a structure in which there.

  This configuration has the following effects.

  The gap between at least the ends on the exhaust port side of the plurality of fins arranged side by side is formed so as to gradually increase from the upstream side to the downstream side of the blower, thereby opening the fins and the exhaust port. The angle formed by the surface can be gradually decreased from the upstream side to the downstream side of the air flow, and the air that changes the air angle as the fan portion rotates can flow smoothly along the fin portion. In addition, heat can be efficiently exchanged with the heat transferred from the heating element such as the MPU to the fin portion, and the heat can be exhausted from the exhaust port.

  By having a plurality of plate-like fins that are erected on the surface of the substrate part inside the casing part and are arranged in parallel between the fan part and the exhaust port, the heat radiation area can be expanded and the heat receiving part can transmit heat. Heated heat can be efficiently dissipated.

  By providing the cover portion with the air inlets disposed substantially concentrically facing the fan portion, air can be taken into the fan portion and can be blown as cooling air.

  Here, as the material of the casing part and the cover part, aluminum, aluminum alloy, copper, copper alloy and the like having good thermal conductivity and heat dissipation are preferably used.

  The casing part is formed in a flat and substantially rectangular shape, and an exhaust port is formed on one side surface of the peripheral wall part surrounding the outer periphery of the substrate part. A substantially arc-shaped air passage is formed in the casing portion so as to communicate with the exhaust port, and a fan portion is disposed in the air passage.

The fan unit has a motor unit disposed substantially at the center of the air passage and a plurality of blades radially disposed on the outer periphery of the motor unit. The mounting direction of the blades differs depending on the rotation direction of the fan unit. When the rotation direction of the fan part is counterclockwise (counterclockwise) when viewed from the intake port side on the upper surface, the blades are arranged on the right side of the tangential direction of the outer periphery of the motor unit, and the rotation direction of the fan unit is on the intake port side of the upper surface When viewed clockwise, the blade is disposed on the left side in the tangential direction of the outer periphery of the motor unit.

  In addition, when the rotation direction of the fan part is counterclockwise (counterclockwise) when viewed from the intake port on the upper surface, the air inflow start point at the lower right of the air passage is on the upstream side of the air flow, and then rotates counterclockwise from there. And the fin part of the left end becomes the ventilation upstream side, and the right fin part becomes the ventilation downstream side. When the rotation direction of the fan part is clockwise (clockwise) when viewed from the air inlet side on the upper surface, the air inflow start point at the lower left of the air passage is the upstream side of the air flow, and rotates clockwise from there to the right end fin The portion is the upstream side of the air flow, and the left fin portion is the downstream side of the air flow.

  The fan portion has an outer shape and a thickness that is flat and substantially circular so as to be within the air passage inside the casing portion. As the material of the fan part, a lightweight synthetic resin is preferably used in order to reduce the weight of the entire cooling fan.

  In addition, a screw hole is drilled in the casing portion for attachment to a computer device, an information device, or the like.

  In addition, at the position facing the fin part on the back side of the substrate part of the casing part, it is in close contact with a heating element such as an MPU and has a flat area wider than the outer shape of the heating element so that heat generated by the heating element can be absorbed efficiently. A heat receiving portion is formed.

  By having a plurality of plate-like fins that are erected on the surface of the substrate part inside the casing part and arranged in parallel between the fan part and the exhaust port, the heat radiation area can be expanded, and heat transfer from the heat receiving part The generated heat can be efficiently dissipated.

  The interval between the end portions on the exhaust port side of adjacent fin portions is preferably 2 mm to 4 mm. As the gap between fins becomes narrower than 2 mm, manufacturing tends to be difficult and the exhaust port tends to become clogged. As the gap between fins becomes wider than 4 mm, the number of elements in the fins decreases and the surface area becomes insufficient. Therefore, there is a tendency that the heat dissipation effect tends to be lowered, both of which are not preferable.

  The air inlets formed in the cover part are arranged substantially concentrically facing the fan part in order to take air into the fan part.

2nd invention made | formed in order to solve the said subject is a cooling fan as described in 1st invention, Comprising: Plurality from 1st of the ventilation upstream side arranged in parallel to the nth of ventilation downstream Θ _{i + 1} = θ ₁ −i × k (provided that the angle formed between the end of the i-th fin portion on the exhaust port side and the opening end surface of the exhaust port is θ _i) , i is an integer of 1 or more (n-1) or less, n is an integer of 2 or more, and k is an angle constant), and the range of the angle constant k is 1 ° to 6 °.

  With this configuration, in addition to the operation of the first invention, the following operation is provided.

  The angle formed by the end on the exhaust port side of the plurality of fins from the first on the upstream side of the blower to the nth on the downstream side of the blower and the opening end surface of the exhaust port is from the upstream side of the blower to the downstream of the blower Since it is formed so as to gradually decrease by a certain angle toward the side, air that changes the angle that is blown with the rotation of the fan part can flow smoothly along the fin part, such as MPU Heat can be efficiently exchanged with the heat transferred from the heating element to the fin portion, and heat can be exhausted from the exhaust port.

  Since the angle formed between the end on the exhaust port side of the plurality of fins from the first on the upstream side of the blower to the nth on the downstream side of the blower and the open end surface of the exhaust port is defined. Even when the sizes of the part, the fan part, the fin part, etc. are different, the number and shape of the fin parts can be easily designed.

  Here, when the rotation direction of the fan part is counterclockwise (counterclockwise) when viewed from the intake port side of the upper surface, the first fin portion on the upstream side of the air flow becomes the left end, and the rotation direction of the fan unit is the intake air of the upper surface. When viewed clockwise from the mouth side (clockwise), the first fin portion on the upstream side of the blower is the right end.

The angle θ ₁ formed between the end on the exhaust port side of the first fin portion and the opening end surface of the exhaust port is formed at a substantially right angle.

  The angle constant k is preferably 1 ° to 6 °, more preferably 3 ° to 4 °. As the angle constant k becomes smaller than 3 ° or larger than 4 °, the air volume exhausted from the exhaust port tends to decrease, and the angle constant k becomes smaller than 1 ° or larger than 6 °. As such, the tendency becomes remarkable, which is not preferable.

  The number n of elements of the fin portion is determined by the relationship between the width of the exhaust port of the casing portion and the angle constant k. In addition, it is preferable to form the space | interval of the edge part by the side of the exhaust port of an adjacent fin part to 2 mm-4 mm as above-mentioned irrespective of the value of the angle constant k.

  3rd invention made | formed in order to solve the said subject is a cooling fan as described in 1st or 2nd invention, Comprising: The distance to the outer peripheral surface of a fan part and the inner peripheral wall surface of an air path is a ventilation upstream side It has the structure which increases gradually toward the rotation direction from the air flow to the air flow downstream side.

  By gradually increasing the distance between the outer periphery of the fan section and the inner peripheral wall surface of the air passage from the upstream side of the air flow to the downstream side of the air flow in the rotational direction, there is less air passage resistance in the air flow downstream portion, and a large amount of cooling air The heat transferred from the heating element such as the MPU to the fin portion can be efficiently exchanged with the cooling air from the fan portion, and can be exhausted from the exhaust port.

  By gradually increasing the distance between the outer periphery of the fan section and the inner peripheral wall surface of the air passage from the upstream side of the air flow to the downstream side of the air flow in the rotational direction, pressure fluctuation does not occur inside the air passage, and smooth Cooling air can be blown to the vortex, vortex and turbulence can be prevented, and noise can be reduced.

  Here, in order to gradually increase the distance from the outer periphery of the fan unit to the inner peripheral wall surface of the air passage from the upstream side of the air flow to the downstream side of the air flow in the rotational direction, the radius of the inner wall surface of the air passage is It may be formed so as to gradually increase in the rotational direction from the air blowing upstream side to the air blowing downstream side, or the rotation center of the fan part is shifted to the air blowing upstream lower end side with respect to the air passage formed with a certain radius. As described above, the mounting position of the fan unit may be shifted. When the mounting position of the fan part is shifted instead of changing the radius of the inner wall surface of the air path, the air path can be easily formed, and it is only necessary to adjust the mounting position of the fan part during assembly, resulting in excellent productivity.

The minimum gap between the inner wall surface at the air inflow start point at the upstream end of the air passage and the outer diameter of the fan portion is formed to be 1 mm to 3 mm. As the minimum gap becomes smaller than 1 mm, the fan portion and the casing portion are likely to come into contact with each other due to the effects of assembly accuracy of the fan portion, thermal deformation, etc., and there is a tendency to lack productivity and reliability, and the minimum gap becomes larger than 3 mm. As the size of the fan portion becomes smaller, the air volume and static pressure tend to decrease, and the heat dissipation efficiency tends to decrease, which is not preferable.

4th invention made | formed in order to solve the said subject is a cooling fan as described in any 1 invention among 1st thru | or 3rd invention, Comprising: It is a lower end part of the ventilation upstream side of an air path. The inner wall surface radius of the air path from the air inflow start point to the horizontal axis passing through the center of the fan part on the downstream side of the air blower is R ₀ , and the inside of the air path for every 45 ° rotation to the air blower downstream side with reference to the rotation center of the fan part R _j = R ₀ + j × ΔR (where j is an integer from 1 to 4) where R _{j is} the wall surface radius and ΔR is the amount of increase in radius every 45 ° rotation. .

With respect to the inner wall radius _R0 of the air passage from the air inflow start point, which is the lower end portion on the upstream side of the air passage, to the horizontal axis passing through the center of the fan portion on the downstream side of the air passage, the air is blown based on the rotation center of the fan portion. The inner wall radius R _j of the air passage for every 45 ° rotation to the downstream side increases by a radius increase amount ΔR for every 45 ° rotation, and R _j = R ₀ + j × ΔR (where j is an integer from 1 to 4) because it has a relationship to), each predetermined angle in only increases the inner wall radius R _j of the air passage, certainly can increase the width of air path from the air upstream to the blower downstream processing Excellent in productivity and productivity, can reduce the air passage resistance in the downstream part of the blower, can blow a large amount of cooling air to the fin part, and transfers heat from a heating element such as MPU to the fin part Heat can be efficiently exchanged between heat and cooling air.

Here, the inner wall surface radius R ₀ of the air passage from the air inflow start point which is the lower end portion on the upstream side of the air passage to the horizontal axis passing through the center of the fan portion on the downstream side of the air passage is the minimum radius of the air passage, The outer radius of the fan portion is equal to the minimum gap between the fan portion and the inner wall surface of the air passage.

By the inner wall radius R _j of the air passage of the center of rotation 45 ° rotation each based fan unit is increased by [Delta] R, toward the blower downstream from the air upstream side without substantially increasing the number of divisions of the air passage The width of the air passage can be reliably increased, and the workability and productivity of the air passage having an effect sufficient for improving the heat radiation effect can be improved.

  The radius increase amount ΔR is preferably 1 mm to 4 mm. As the radius increase ΔR becomes smaller than 1 mm, the static pressure in the air passage becomes higher, the air volume to be discharged tends to be insufficient, and the cooling efficiency tends to decrease. As the radius increase ΔR becomes larger than 4 mm, The air passage becomes too large to accommodate the casing part in a limited space, and the pressure generated by the air passage and the fan blades does not act effectively, and the pressure loss of the fan part tends to increase. However, neither is preferable.

  A fifth invention made to solve the above-mentioned problems is the cooling fan according to the fourth invention, wherein the center of the minimum radius of the inner wall surface of the air passage coincides with the rotation center of the fan portion. The portion is arranged.

  Since the fan part is arranged so that the center of the minimum radius of the inner wall surface of the air passage matches the rotation center of the fan part, the fan blades do not interfere with the inner wall surface of the air passage. Can be prevented, and the width of the air passage can be reliably increased from the upstream side of the air flow toward the downstream side of the air flow, the air passage resistance in the downstream portion of the air flow can be reduced, and a large air volume can be reduced. Cooling air can be blown.

Here, when viewed on the horizontal axis passing through the center of the fan section, the inner wall surface radius R ₀ on the upstream side of the air passage is the minimum radius of the air passage, and the inner wall surface radius R ₄ on the downstream side of the air passage is the air passage. The center position of the fan part is offset from the center position in the width direction of the casing part and is arranged on the upstream side of the air passage.

  The fan part is arranged so that the outer radius of the fan part is smaller than the minimum radius of the inner wall surface of the air passage, and the center of the minimum radius of the inner wall surface of the air passage coincides with the rotation center of the fan part. The blades of the part can be disposed in the air passage without interfering with the inner wall surface of the air passage.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is an overall perspective view showing a cooling fan in Embodiment 1 of the present invention, FIG. 2 is an exploded perspective view showing the cooling fan in Embodiment 1 of the present invention, and FIG. 3 is an embodiment of the present invention. It is a back side perspective view which shows the cooling fan in the form 1.

  In FIG. 1, 1 is a cooling fan according to Embodiment 1 of the present invention, 2 is a cooling formed in a flat, substantially rectangular shape with a metal such as aluminum, aluminum alloy, copper, copper alloy, etc. having good thermal conductivity and heat dissipation. The casing portion of the fan 1, 2 a is a base plate portion of the casing portion 2 formed in a flat plate shape, and 2 b is a peripheral wall portion of the casing portion 2 formed by surrounding the outer periphery of the base plate portion 2 a and standing on the surface of the base plate portion 2 a. 3 is a rectangular exhaust port of the casing portion 2 formed on one side surface of the peripheral wall portion 2b, 4 is an air passage formed in a substantially superior arc shape in communication with the exhaust port 3 inside the casing portion 2, and 4a An air inflow start point 5 on the upper right side of the air passage 4 on the upstream side of the air passage 4 includes a motor portion 6 disposed in the air passage 4 and a plurality of blades 7 radially disposed on the outer periphery of the motor portion 6. The fan part 8 has an inner surface of the casing part 2 on the surface of the substrate part 2a. A plurality of plate-like fin portions 9 arranged in parallel between the fan portion 5 and the exhaust port 3, 9 is a cover formed on the upper surface of the peripheral wall portion 2 b of the casing portion 2 and made of the same material as the casing portion 2. And 9a are substantially circular air inlets that face the fan unit 5 and penetrate through the cover unit 9, and 10 is a heat receiving unit that is formed flat at a position facing the fin unit 8 on the back surface of the substrate unit 2a. It is a heating element such as an MPU disposed in close contact with 2c.

  Since the heat receiving part 2c formed on the back surface of the substrate part 2a of the casing part 2 is flat and has an area larger than the outer shape of the heating element 10, heat generated by the heating element 10 can be absorbed efficiently.

  In addition, by having a plurality of plate-like fin portions 8 which are erected on the surface of the substrate portion 2 a inside the casing portion 2 and are arranged in parallel between the fan portion 5 and the exhaust port 3, the heat radiation area of the casing portion 2 is obtained. The heat transferred from the heat receiving portion 2c can be efficiently radiated.

  In the present embodiment, the rotation direction of the fan unit 5 is counterclockwise (counterclockwise) when viewed from the intake port 9a on the upper surface, and the blades 7 are disposed on the tangential right side of the outer periphery of the motor unit 6. Yes.

  Moreover, it rotates counterclockwise from the air inflow start point 4a on the upstream side of the air flow path 4 at the lower right side of the air passage 4, and the fin portion 8 at the left end becomes the upstream side of the air flow and the right fin portion 8 becomes the downstream side of the air flow.

  The fan unit 5 has a plurality of blades 7 and generates wind by rotating around a rotation shaft (not shown) at the center of the fan unit 5.

  The air inlet 9 a formed in the cover portion 9 is disposed substantially concentrically facing the fan portion 5 in order to take air into the fan portion 5.

  Next, the detail of a fin part is demonstrated.

  FIG. 4 is a principal plan view showing the fin portion of the cooling fan in the first embodiment of the present invention.

In FIG. 4, 3a is the opening end face of the exhaust port 3 of the casing part 2, and θ _{1 to} θ _n are the first on the upstream side (left side) and the nth on the downstream side (right side). This is the angle formed by the end of the plurality of fins 8 on the exhaust port 3 side and the open end surface 3a of the exhaust port 3.

Here, when the angle formed between the end of the i-th fin portion 8 on the exhaust port 3 side and the opening end surface 3a of the exhaust port 3 is θ _i ,
θ _{i + 1} = θ ₁ −i × k (Equation 1)
(Where i is an integer of 1 or more and (n-1) or less, n is an integer of 2 or more, and k is an angle constant).

  By forming the fin portion 8 according to the relationship of (Equation 1), the interval between the end portions on the exhaust port 3 side of the plurality of fin portions 8 arranged in parallel is changed from the upstream side (left side) to the downstream side (right side). It is gradually increased toward.

  The range of the angle constant k was 1 ° to 6 °. It has been found that as the angle constant k becomes smaller than 1 ° or larger than 6 °, the air volume exhausted from the exhaust port is extremely decreased, which is not preferable.

  Moreover, the space | interval of the edge part by the side of the exhaust port 3 of the adjacent fin part 8 was formed in 2 mm-4 mm. As the interval between the fin portions 8 becomes smaller than 2 mm, the manufacture becomes difficult and the exhaust port 3 tends to be clogged. As the interval between the fin portions 8 becomes larger than 4 mm, the number of elements of the fin portion 8 decreases. It has been found that the surface area tends to be insufficient and the heat dissipation effect tends to decrease, which is not preferable.

The angle θ ₁ formed between the end portion of the first fin portion 8 on the exhaust port 3 side and the opening end surface 3a of the exhaust port 3 is formed at a substantially right angle, and the end portion of the fin portion 8 on the fan portion 5 side is formed. The interval was constant regardless of the location.

  Next, the details of the air path will be described.

  FIG. 5 is a main part plan view showing the air path of the cooling fan in the first embodiment of the present invention.

In FIG. 5, φA is the outer diameter of the fan portion 5, and G is the minimum of the inner wall surface of the peripheral wall portion 2 b and the outer diameter of the fan portion 5 at the air inflow start point 4 a at the upstream end of the air passage 4. The gap, R _0, is the inner wall surface radius of the air passage 4 from the air inflow start point 4a, which is the lower end portion on the upstream side of the air passage 4, to the horizontal axis passing through the center of the fan portion 5 rotated 45 ° to the air downstream side, R _{1 to} R ₄ are the inner wall surface radii of the air passage 4 for every 45 ° rotation toward the blower downstream side with respect to the rotation center of the fan unit 5.

Here, when the amount of increase in radius every 45 ° rotation is ΔR,
R _j = R ₀ + j × ΔR (Equation 2)
(Where j is an integer from 1 to 4)
It was.

  By forming the air passage 4 according to the relationship of (Equation 2), the distance from the outer periphery of the fan unit 5 and the inner peripheral wall surface of the air passage 4 is gradually increased from the upstream side of the air flow to the downstream side of the air flow in the rotational direction. ing.

Thereby, the distance from the outer periphery of the fan part 5 in the air passage 4 to the inner peripheral wall surface of the air passage 4 is on the way from the air inflow start point 4a at the end on the upstream side of the air flow to the exhaust port 3 on the downstream side of the air flow. Since it can be prevented from narrowing or widening suddenly, pressure fluctuations are prevented from occurring inside the air passage 4, and vortex and turbulence are prevented from flowing, allowing cooling air (air) to flow smoothly. And noise can be reduced.

When viewed on the horizontal axis passing through the center of the fan unit 5, the inner wall surface radius R ₀ on the upstream side of the air passage 4 is the minimum radius of the air passage 4, and the inner wall surface radius R ₄ of the air passage 4 on the downstream side of the air passage ₄ is the wind. It is the maximum radius of the path 4, and the center position of the fan part 5 is offset to the right side of the air path 4 with respect to the center position in the width direction of the casing part 2.

Further, the fan portion 5 has an outer radius smaller than the minimum radius R ₀ of the inner wall surface of the air passage 4, and the center of the minimum radius R ₀ of the inner wall surface of the air passage 4 coincides with the rotation center of the fan portion 5. Since the part 5 is disposed, the blade 7 of the fan part 5 can be disposed in the air path 4 without causing interference with the inner wall surface of the air path 4.

  The minimum gap G between the inner wall surface at the air inflow start point 4a at the end of the air passage 4 on the upstream side of the air flow and the outer diameter of the fan unit 5 was formed to be 1 mm to 3 mm. As the minimum gap G becomes smaller than 1 mm, the fan part 5 and the inner wall surface of the peripheral wall part 2b of the casing part 2 easily come into contact with each other due to the assembly accuracy of the fan part 5, thermal deformation, etc., and productivity and reliability are lacking. As the minimum gap G becomes larger than 3 mm, the size of the fan part 5 becomes smaller, the air volume and the static pressure tend to decrease, and the heat radiation efficiency tends to decrease. .

  Further, the radius increase amount ΔR was formed to be 1 mm to 4 mm. As the radius increase amount ΔR becomes smaller than 1 mm, the static pressure in the air passage 4 becomes higher, the air volume to be discharged tends to be insufficient, and the cooling efficiency tends to decrease, and as the radius increase amount ΔR becomes larger than 4 mm. The air passage 4 becomes too large to accommodate the casing part 2 in a limited space, and the pressure generated by the air passage 4 and the blades 7 of the fan part 5 does not act effectively, and the pressure of the fan part 5 It has been found that there is a tendency that loss tends to increase, both of which are not preferable.

  The operation of the cooling device according to Embodiment 1 of the present invention configured as described above will be described.

  The heat generated when the heating element 10 such as an MPU performs calculation or the like is transmitted from the heat receiving portion 2c formed on the back surface of the casing portion 2 to the surface side of the substrate portion 2a, and is further erected on the surface of the substrate portion 2a. It is transmitted to a plurality of plate-like fin portions 8 arranged in parallel between the fan portion 5 and the exhaust port 3.

  By heat exchange between the fin portion 8 and the air in contact with the fin portion 8, the heat transmitted to the fin portion 8 is radiated into the air. Since the fin part 8 has a plurality of plate-like elements, the surface area is increased and the contact area with the air is increased to efficiently dissipate heat.

  Here, when the fan unit 5 rotates counterclockwise (counterclockwise) when viewed from the intake port 9 a side of the upper surface of the casing unit 2, air is taken in from the intake port 9 a and is generated as the fan unit 5 rotates. Due to the centrifugal force, the air is forcibly sent as cooling air in the direction of the fin portion 8.

  When the cooling air passes between the plurality of plate-like fin portions 8 arranged in parallel, the heat radiated into the air can be exhausted from the exhaust port 3.

The magnitude of the pressure generated by the rotation of the fan unit 5 does not change to a certain extent as the distance between the fan unit 5 and the inner wall of the peripheral wall 2b of the casing unit 2 increases, but is stored. From the vicinity of the left end where the inner wall shape of the peripheral wall portion 2b of the 2 is changed from an arc shape to a linear shape and the air passage 4 is opened from a closed spatial circle, the blades 7 of the fan portion 5 are on the fan portion 5 side of the fin portion 8 As the (upper end side of the fin portion 8) moves from the upstream side (left side) to the downstream side (right side), the pressure gradually decreases, and the flow velocity increases accordingly.

The cooling air blown from the fan unit 5 is covered with the blade 7 of the fan unit 5 at the position on the fan unit 5 side (upper end side of the fin unit 8) of the first fin unit 8 on the upstream side (left side). When it flows, it almost flows in the direction perpendicular to the surface of the blade 7 by centrifugal force. Therefore, the angle θ ₁ formed by the end of the left end fin portion 8 on the exhaust port 3 side (the lower end side of the fin portion 8) and the opening end surface 3a of the exhaust port 3 is set to a substantially right angle.

  As the blade 7 of the fan unit 5 moves on the fan unit 5 side (upper end side) of the fin unit 8 from the upstream side (left side) to the downstream side (right side), the pressure decreases as described above. The air is discharged from the exhaust port 3 through the fin portion 8 so as to be pulled upstream (left side) where the pressure is higher than the direction perpendicular to the surface of the blade 7.

  Therefore, as shown in FIG. 4, the angle formed by the end of the fin portion 8 on the exhaust port 3 side and the opening end surface 3a of the exhaust port 3 gradually decreases from the upstream side (left side) to the downstream side (right side). By doing so, the fin part 8 can be arranged along the flow of the wind generated by the fan part 5, the flow of cooling air blown by the fan part 5 and passing through the fin part 8 becomes smooth, and the heat dissipation effect In addition, the flow of cooling air having different angles depending on the location can be reliably guided toward the exhaust port 3, and effective exhaust can be performed.

  As described above, since the cooling fan according to Embodiment 1 of the present invention is configured, it has the following operation.

  The angle formed by the end on the exhaust port 3 side of the plurality of fins 8 from the first to the nth on the downstream side of the air flow upstream and the open end surface 3a of the exhaust port 3 is arranged upstream of the air flow. Since air is formed so as to gradually decrease by a certain angle from the side toward the air blowing downstream side, air that changes the angle of air blown along with the rotation of the fan unit 5 can flow smoothly along the fin unit 8. It is possible to efficiently exchange heat with the heat transferred from the heating element 10 such as the MPU to the fin portion 8 and to exhaust heat from the exhaust port.

  An angle formed by the end on the exhaust port 3 side of the plurality of fins 8 from the first to the nth on the downstream side of the blower and the open end surface 3a of the exhaust port 3 is defined. Therefore, even when the casing part 2, the fan part 5, the fin part 8, etc. have different sizes, the number and shape of the fin parts 8 can be easily designed.

The rotation of the fan unit 5 with respect to the inner wall surface radius R ₀ of the air channel 4 from the air inflow start point 4a which is the lower end of the air channel 4 on the upstream side of the air flow to the horizontal axis passing through the center of the fan unit 5 on the air downstream side. The inner wall surface radius R _j of the air passage 4 every 45 ° rotation toward the blower downstream side with respect to the center increases by a radius increase amount ΔR every 45 ° rotation, and R _j = R ₀ + j × ΔR (where j is because it has a relationship to) an integer from 1 to 4, fixed at an angle each to only increase the inner wall radius R _j of the air passage 4, it ensures the air passage 4 from the air upstream to the blower downstream The width can be increased, the workability and productivity are excellent, the air path resistance in the air blowing downstream part can be reduced, the large amount of cooling air can be blown to the fin part 8, and the MPU etc. Exchange heat efficiently between the heat transferred from the heating element 10 to the fin portion 8 and the cooling air. You can.

  By gradually increasing the distance between the outer periphery of the fan unit 5 and the inner peripheral wall surface of the air passage 4 from the upstream side of the air flow toward the downstream side of the air flow, the pressure fluctuation may occur inside the air passage 4. Therefore, it is possible to smoothly blow cooling air, prevent the generation of vortex and turbulence, and reduce noise.

  Since the heat receiving part 2c having a flat area larger than the outer shape of the heat generating element 10 is formed on the back surface of the substrate part 2a of the casing part 2 at a position facing the fin part 8, the heat receiving part 2c and the heat generating element 10 are connected. The heat generated by the heating element 10 can be absorbed efficiently.

  By having a plurality of plate-like fin portions 8 standing on the surface of the substrate portion 2a inside the casing portion 2 and arranged in parallel between the fan portion 5 and the exhaust port 3, the heat radiation area can be expanded. The heat transferred from the heat receiving portion 2c can be efficiently radiated.

  By providing the cover portion 9 with the intake port 9a disposed in a substantially concentric manner so as to face the fan portion 5, air can be taken into the fan portion 5 and can be blown as cooling air.

Since the fan part 5 is disposed so that the center of the minimum radius R ₀ of the inner wall surface of the air passage 4 and the rotation center of the fan part 5 coincide with each other, the blades 7 of the fan part 5 are placed on the inner wall surface of the air passage 4. It is possible to prevent the fan portion 5 from being damaged without interfering with the air passage 4 and to reliably increase the width of the air passage 4 from the upstream side of the air flow toward the downstream side of the air flow. The cooling air with a large air volume can be blown.

  Hereinafter, the present invention will be specifically described by way of examples.

(Example 1)
The angle constant of the cooling fan described in the first embodiment was changed in the range of k = 0 ° to 7 °, and the air volume at the exhaust port 3 at each angle constant was measured.

  At this time, the width of the casing portion 2 was 65 mm, the average pitch of the fin portions 8 was 3.5 mm, and n = 16, which is the number of elements of the fin portions 8.

  FIG. 6 is a diagram showing the relationship between the angle constant and the air volume.

  From FIG. 6, it was found that the air volume increased at the angle constant k = 1 ° to 6 ° than the angle constant k = 0 °, and the cooling effect could be improved.

  Further, it was found that the air volume becomes maximum at the angle constant k = 3 ° to 4 °, and the cooling effect can be enhanced most.

  According to this embodiment, the practical range of the angular constant k is in the range of the angular constant k = 1 ° to 6 °, and more preferably the angular constant k = 3 ° to 4 ° is desirable. It was.

  In the present invention, by changing the shape of the fin portion in accordance with the different air flow directions on the left and right sides of the fan portion, the air can flow along the fin portion, and the exhaust can be effectively exhausted from the exhaust port. It is excellent in reliability, practicality, and productivity, and the air path resistance on the downstream side of the air flow is reduced by forming the radius of the air path from the upstream side to the downstream side in the rotational direction. Can provide a cooling fan with high heat dissipation efficiency, which can blow a cooling air with a large air volume, can perform smooth exhaust, and can be provided in an MPU in a housing of an electronic device such as a personal computer. It can be suitably used as a cooling fan for cooling a heating element such as.

1 is an overall perspective view showing a cooling fan according to Embodiment 1 of the present invention. 1 is an exploded perspective view showing a cooling fan in Embodiment 1 of the present invention. The rear side perspective view which shows the cooling fan in Embodiment 1 of this invention The principal part top view which shows the fin part of the cooling fan in Embodiment 1 of this invention The principal part top view which shows the air path of the cooling fan in Embodiment 1 of this invention Diagram showing the relationship between angle constant and air flow

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling fan 2 Casing part 2a Board | substrate part 2b Perimeter wall part 2c Heat receiving part 3 Exhaust port 3a Opening end surface 4 Air path 4a Air inflow start point 5 Fan part 6 Motor part 7 Blade | wing 8 Fin part 9 Cover part 9a Inlet 10 Heating element

Claims (5)

A casing portion having a substrate portion, a peripheral wall portion that surrounds the outer periphery of the substrate portion and is erected on the surface of the substrate portion, and an exhaust port formed on one side surface of the peripheral wall portion; and an interior of the casing portion An air passage formed in a substantially arcuate shape in communication with the exhaust port, a motor portion disposed in the air passage, and a plurality of blades radially disposed on the outer periphery of the motor portion. A plurality of plate-like fin portions that are provided upright on the surface of the substrate portion on the inner front surface portion of the casing portion, and are arranged in parallel between the fan portion and the exhaust port, and the peripheral wall of the casing portion At least the exhaust of at least one of the plurality of fins arranged side by side, and a cover part that covers the upper surface of the part and an air inlet that penetrates the cover part and faces the fan part The distance between the mouth side ends gradually from the air blowing upstream side toward the air blowing downstream side. A cooling fan, characterized by being formed so as to pressure. For the plurality of fin portions from the first on the upstream side of the air flow to the nth on the downstream side of the air flow, an end on the exhaust port side of the i-th fin portion and an open end surface of the exhaust port, When the angle between is θ _i ,
θ _{i + 1} = θ ₁ −i × k
(Where i is an integer of 1 or more and (n-1) or less, n is an integer of 2 or more, and k is an angle constant)
The cooling fan according to claim 1, wherein the range of the angle constant k is 1 ° to 6 °. 3. The cooling fan according to claim 1, wherein a distance from the outer periphery of the fan part to the inner peripheral wall surface of the air passage gradually increases in the rotation direction from the upstream side to the downstream side. . R ₀ is the inner wall surface radius of the air path from the air inflow start point, which is the lower end of the air flow upstream of the air path, to the horizontal axis passing through the center of the fan part on the air downstream side, and the rotation center of the fan part the inner wall radius of the air passage of the 45 ° rotation each to the blower downstream relative to the radius increase of R _j, rotated 45 ° each time when a _{ΔR R j = R 0 + j} × ΔR
(Where j is an integer from 1 to 4)
The cooling fan according to any one of claims 1 to 3, wherein the cooling fan is any one of the above. 5. The cooling fan according to claim 4, wherein the fan portion is disposed so that a center of a minimum radius of an inner wall surface of the air path coincides with a rotation center of the fan portion.

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