TWI546457B - Heat dissipation device and centrifugal fan thereof - Google Patents

Description

Heat sink and centrifugal fan

The invention relates to a heat dissipating device, in particular to a centrifugal fan of a heat dissipating device.

At present, in the computer, a heat dissipation module composed of a heat pipe, a heat dissipation fin group and a centrifugal fan is often used to dissipate heat from the heat-generating electronic components. The heat-generating electronic component transfers heat to the heat-dissipating fin set by the heat pipe, and the heat-dissipating fin set is disposed at the air outlet of the centrifugal fan. The airflow generated by the centrifugal fan blows toward the heat sink fin group and exchanges heat with the heat sink fin group, thereby dissipating heat. Therefore, the centrifugal fan plays an extremely important role in the heat dissipation module.

The conventional centrifugal fan includes a frame and an impeller housed in the fan frame, the fan frame is provided with an air outlet, and the impeller drives the airflow to be blown out from the air outlet, and the airflow exchanges heat with the heat dissipation fin group, thereby The heat of the heat-emitting electronic components is dissipated. However, since the airflow leaves the air outlet of the centrifugal fan, the airflow generally travels in a tangential direction with the outer edge of the impeller, so that part of the airflow enters the heat dissipation fin group and forms an angle with the heat dissipation fin group at the portion, the partial airflow Collision with the heat sink fins at the place causes the noise of the heat dissipation module to increase.

In view of this, it is necessary to provide a heat sink with less noise and its use Heart fan.

A centrifugal fan includes a frame and an impeller housed in the fan frame and having a plurality of blades. One side of the fan frame is provided with an air outlet, and the air outlet has a near wind end and a windward end opposite the windward end, the impeller driving airflow flowing from the near wind end and the far wind end of the air outlet, the fan frame is provided with a flow guiding portion at a windward end of the air outlet The flow guiding portion extends from the edge of the air outlet toward the inside of the fan frame and the side of the near wind end, and the flow guiding portion flows the airflow flowing to the far wind end along the airflow flowing out from the near wind end. The directions are derived in parallel.

A heat dissipating device includes a centrifugal fan and a heat dissipating fin set disposed at an air outlet of the centrifugal fan, the centrifugal fan including a frame and an impeller housed in the fan frame and having a plurality of blades One side of the fan frame is provided with an air outlet, the air outlet has a near wind end and a far wind end opposite to the near wind end, and the impeller drives the air flow from the near end of the air outlet and the wind The fan frame is provided with a flow guiding portion at a windward end of the air outlet, and the flow guiding portion is curved from an edge of the air outlet toward the inside of the fan frame and the side of the near wind end. Extendingly, the heat dissipation fin group is composed of a plurality of heat dissipation fins, and an outer end of the flow guiding portion is parallel to the heat dissipation fin.

The flow guiding portion of the centrifugal fan in the heat dissipating device guides the airflow to the heat dissipating fin group substantially in parallel, thereby reducing noise and energy loss caused by collision of the airflow and the fins, and the flow velocity of the airflow is not greatly reduced. Improve the heat exchange efficiency between the heat sink fin group and the airflow, thereby improving the heat dissipation performance of the heat sink.

100‧‧‧heating device

10‧‧‧ Centrifugal fan

11‧‧‧Base

111‧‧‧floor

112‧‧‧ side wall

113‧‧‧ tongue mouth

114‧‧‧First curved surface

115‧‧‧Second curved surface

116‧‧‧ Connection

12‧‧‧ top board

13‧‧‧ fan leaves

14‧‧‧ Impeller

15‧‧‧ accommodating space

16‧‧‧Air inlet

17‧‧‧air outlet

171‧‧‧ Near wind end

172‧‧‧ far wind end

18‧‧‧Drainage Department

181‧‧‧ inner end

182‧‧‧Outside

20‧‧‧Fixing fin group

21‧‧‧ Heat sink fins

22‧‧‧Air passage

23‧‧‧ First end

24‧‧‧second end

1 is an exploded perspective view of a heat sink according to a preferred embodiment of the present invention.

2 is an assembled, isometric view of the heat sink shown in FIG. 1.

3 is a horizontal cross-sectional view and a flow field diagram of the heat sink shown in FIG. 2.

The present invention will be further described below in conjunction with the embodiments with reference to the accompanying drawings.

Referring to FIG. 1 and FIG. 2 , a heat dissipation device 100 according to an embodiment of the invention includes a centrifugal fan 10 and a heat dissipation fin set 20 . The heat sink fin set 20 is thermally coupled to a heat generating electronic component (not shown) to absorb heat generated by the heat generating electronic component. The centrifugal fan 10 provides airflow to the heat sink fin set 20 to absorb the heat sink fin set 20 The heat is dissipated into the surrounding air.

The centrifugal fan 10 includes a base 11, a top plate 12 disposed on the base 11, and an impeller 14 having a plurality of blades 13. The base 11 and the top plate 12 define a receiving space 15 , and the impeller 14 is disposed in the receiving space 15 . The impeller 14 operates in a counterclockwise direction when the centrifugal fan 10 is in operation.

The base 11 includes a bottom plate 111 and a side wall 112 extending upward from a periphery of the bottom plate 111. The top plate 12 is connected to the top end of the side wall 112, and the top plate 12 and the bottom plate 111 are parallel to each other and disposed opposite to each other. An air inlet 16 is defined in the middle of the bottom plate 111 and the top plate 12 corresponding to the position of the impeller 14. The side wall 112 has a spiral shape, and one side of the air outlet opening 16 is perpendicular to the air inlet 16 . In the present embodiment, the air outlet 17 has a proximal end 171 and a distal end 172 opposite the proximal end 171. When the centrifugal fan 10 is in operation, the fan blade 13 of the impeller 14 drives the airflow to flow through the inner surface of the side wall 112 and flows to the air outlet 17, wherein a part of the airflow flows out from the proximal air end 171, and another part of the airflow from the near wind End 171 flows to the windward end 172. The side wall 112 extends in a straight line on the near wind end 171 side, and the side wall 112 extends in a curved manner on the far wind end 172 side.

Referring to FIG. 3, the inner surface of the side wall 112 protrudes inwardly from the side of the windward end 172 of the air outlet 17 to form a tongue 113. The outer surface of the side wall 112 is corresponding to the tongue 113. Recessively recessed inward. The tongue 113 has a generally "V" shape in cross section, and the inner surface of the tongue 113 includes a first curved surface 114 facing away from the windward end 172 and toward the impeller 14 and toward and toward the windward end 172. A second curved surface 115 is smoothly connected to the second curved surface 115 at the middle of the tongue 113. The first curved surface 114 intersects the second curved surface 115 at a junction 116. The distance of the first curved surface 114 from the free end of the blade 13 of the impeller 14 gradually increases in the direction in which the impeller 14 operates, so the joint 116 is closest to the free end of the blade 13, thereby increasing the flow therethrough. The pressure of the air stream, which in turn increases its flow rate. The second curved surface 115 extends from the joint 116 to the edge of the air outlet 17. The distance between the second curved surface 115 and the side wall 112 on the side where the proximal end 171 is located is gradually increased from the joint 116 toward the edge of the air outlet 17. The curvature of the second curved surface 115 gradually decreases from the joint 116 toward the edge of the air outlet 17, the second curved surface 115 reduces the resistance experienced by the airflow passing therethrough and directs the airflow to substantially The side wall 112 on the side where the near-wind end 171 is located is blown in a direction parallel to the side.

The bottom plate 111 protrudes upwardly from the air outlet 17 with a flow guiding portion 18, and the guiding portion 18 is located on a side where the windward end 172 of the air outlet 17 is located and is opposite to the side wall 112 of the side where the windward end 172 is located. interval. The flow guiding portion 18 is perpendicular to the bottom plate 111 of the centrifugal fan 10, and the height of the flow guiding portion 18 is equivalent to the height of the side wall 112. The air guiding portion 18 has an opposite inner end 181 and an outer end 182. The inner end 181 is away from the air outlet 17 and is located in the receiving space 15 of the centrifugal fan 10. The outer end 182 is closer to the outer end than the inner end 181. The tuyere 17 extends outwardly to be flush with the edge of the bottom plate 111. In the embodiment, the flow guiding portion 18 has a substantially arc shape. The flow guiding portion 18 is bent and extended from the edge of the air outlet 17 toward the inner side of the centrifugal fan 10 and the side of the near wind end 171, so that the flow guiding portion The distance between the portion 18 and the side wall 112 on the near-air end 171 side is gradually decreased from the edge of the air outlet 17 toward the inside of the centrifugal fan 10. The outer end 182 of the flow guiding portion 18 is substantially parallel to the side wall 112 on the side where the windward end 171 is located.

The heat dissipation fin group 20 is located at the air outlet 17 of the centrifugal fan 10. The heat dissipation fin group 20 is formed by stacking a plurality of heat dissipation fins 21 parallel to each other, and an air flow is formed between each adjacent two heat dissipation fins 21 . Channel 22. The heat dissipation fin group 20 has a first end portion 23 and a second end portion 24, and the first end portion 23 and the second end portion 24 respectively correspond to the wind end 171 of the air outlet 17 of the centrifugal fan 10 and Far wind end 172. The side wall 112 of the centrifugal fan 10 is substantially parallel to the heat dissipation fin 21 on the near wind end 171 side. The outer end 182 of the flow guiding portion 18 extends in a direction substantially parallel to the heat dissipation fins 21. The end of the second curved surface 115 of the tongue 113 extends in a direction substantially parallel to the heat dissipation fin 21. The heat sink fin set 20 is thermally coupled to the heat generating electronic component by a heat pipe (not shown) to absorb heat generated by the heat generating electronic component.

When the centrifugal fan 10 is in operation, the impeller 14 rotates in a counterclockwise direction, and the driving airflow enters from the air inlet 16 into the interior of the centrifugal fan 10, and the airflow is pressurized through the tongue 113 along the side wall 112 of the centrifugal fan 10. The inner surface flows out of the air outlet 17, and a part of the airflow is blown from the near wind end 171 in a direction substantially parallel to the heat dissipation fins 21 at the first end portion 23 of the heat dissipation fin group 20, and flows to the heat dissipation fin group. In the air flow passage 22 of 20; another portion of the air flow flows toward the windward end 172 of the air outlet 17 in a direction at an angle with the heat dissipation fins 21. A portion of the airflow flowing toward the windward end 172, the portion of which encounters the flow guiding portion 18 and, under the guidance of the flow guiding portion 18, flows toward the outer end 182 along the inner end 181 of the flow guiding portion 18, and then The heat dissipation fins 21 of the second end portion 24 of the heat dissipation fin group 20 flow in a substantially parallel direction to the air flow passage 22 of the heat dissipation fin group 20; and another portion of the air flow to the windward end 172 passes over the flow guiding portion 18 In the The side wall 112 on the side of the windward end 172 also flows into the air flow passage 22 of the heat dissipation fin group 20 in a direction substantially parallel to the heat dissipation fins 21 at the second end portion 24. Thus, the airflows flowing to the first end portion 23 and the second end portion 24 of the heat dissipation fin group 20 are substantially parallel to the heat dissipation fins 21 at the same place, so that the flow direction of the airflow toward the heat dissipation fins 21 is reduced, which can be reduced. The noise and energy loss caused by the collision of the airflow with the heat dissipation fins 21, at the same time, the flow velocity of the airflow is not greatly reduced, and the heat exchange efficiency between the heat dissipation fin group 20 and the airflow is improved, thereby improving the heat dissipation performance of the heat dissipation device 100.

It can be understood that the shape of the flow guiding portion 18 is not limited to the shape in the embodiment, and may also be a parabolic shape, a streamline shape, or the like, which is advantageous for guiding the airflow shape, and can guide the airflow to be substantially parallel to the heat dissipation. The fins 21 are sufficient, and the outer end 182 of the flow guiding portion 18 can also protrude from the air outlet 17 of the centrifugal fan 10. In addition, the number of the flow guiding portions 18 is not limited, and a plurality of mutually spaced flow guiding portions may be disposed at the air outlet of the centrifugal fan 10 according to actual heat dissipation requirements to guide the airflow to the heat radiating fins more uniformly and in parallel.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

100‧‧‧heating device

10‧‧‧ Centrifugal fan

11‧‧‧Base

111‧‧‧floor

112‧‧‧ side wall

12‧‧‧ top board

13‧‧‧ fan leaves

14‧‧‧ Impeller

15‧‧‧ accommodating space

16‧‧‧Air inlet

17‧‧‧air outlet

171‧‧‧ Near wind end

172‧‧‧ far wind end

18‧‧‧Drainage Department

20‧‧‧Fixing fin group

21‧‧‧ Heat sink fins

22‧‧‧Air passage

23‧‧‧ First end

24‧‧‧second end

Claims (10)

A centrifugal fan includes a frame and an impeller housed in the fan frame and having a plurality of blades. One side of the fan frame is provided with an air outlet, and the air outlet has a near wind end and The impeller end drives a gas flow from the near wind end and the far wind end of the air outlet, and the improvement is that the fan frame is provided only at the far wind end of the air outlet. a flow portion, the flow guiding portion is curvedly extended from an edge of the air outlet toward the inside of the fan frame and the side of the near wind end, and the flow guiding portion flows the airflow toward the far wind end along the near wind end The flow direction of the outflowing airflow is parallel, and the fan frame includes a bottom plate, a top plate opposite to the bottom plate, and a side wall connecting the bottom plate and the top plate, wherein the flow guiding portion is disposed on the bottom plate and perpendicular to the bottom plate In the bottom plate, the flow guiding portion is adjacent to a sidewall of the windward end side and spaced apart from the sidewall. The centrifugal fan according to claim 1, wherein the height of the flow guiding portion is equivalent to the height of the side wall. The centrifugal fan according to claim 1, wherein the side wall extends in a straight line on the near wind end side, and the side wall extends in a curved manner on the far wind end side. The centrifugal fan of claim 3, wherein an inner surface of the side wall is provided with a tongue opening at a distal wind end adjacent to the air outlet, and the tongue port has a V-shaped cross section. The centrifugal fan of claim 4, wherein the inner surface of the tongue includes a first curved surface facing away from the windward end and facing the impeller, and a first portion facing and facing the far wind end a second curved surface, the first curved surface and the second curved surface are smoothly connected in the middle of the tongue opening, and the distance of the first curved surface from the free end of the blade of the impeller is in the direction of the impeller running Gradually increasing, the second curved surface extends to the edge of the air outlet, and the distance between the second curved surface and the side wall on the side where the near-wind end is located gradually increases from the inside to the outside of the fan frame . The centrifugal fan according to claim 5, wherein the end of the second curved surface is adjacent to the near The side walls on the side where the wind end is located are parallel. The centrifugal fan according to any one of claims 1 to 6, wherein the flow guiding portion includes an inner end and an outer end, the outer end being closer to the air outlet than the inner end, the guide The outer end of the flow portion is parallel to the side wall on the side where the near-wind end is located. The centrifugal fan of claim 7, wherein the outer end of the flow guiding portion extends outward to be flush with an edge of the bottom plate. The centrifugal fan according to claim 7, wherein the flow guiding portion has an arc shape, and a distance between the flow guiding portion and a side wall of the near wind end side is from an edge of the air outlet. The interior toward the centrifugal fan is gradually reduced. A heat dissipating device comprising a centrifugal fan according to any one of claims 1 to 9 and a heat dissipating fin set provided at an air outlet of the centrifugal fan, wherein the heat dissipating fin group is composed of a plurality of heat dissipating fins The outer end of the flow guiding portion is parallel to the heat dissipation fin.