I337j543 _ 099年10月27日核正替換頁 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明涉及一種離心風扇，特別係涉及一種適用於筆記 型電腦散熱之離心風扇。 【先前技術】 [0002] 近年來隨著電子產業之發展，電子元件之性能不斷提升 ，運算速度越來越快，其工作時所散發之熱量相應增加 ，如果這些熱量不及時散發出去，將極大影響電子元件 之性能，使電子元件之運算速度降低，隨著熱量之不斷 累積，還可能燒毁電子元件，因此必須對電子元件進行 散熱，比如在筆記型電腦中，在有限之系統空間内，對 電子元件散熱通常採用佔用空間較小之離心風扇。 * [0003] 該離心風扇通常包括一扇框、一輪轂及以輪轂為中心呈 輻射狀向外延伸之複數扇葉，該扇框具有分別位於其頂 面和底面之上、下進風口及側面之一出風口。工作時， 通過扇葉旋轉帶動周圍空氣流動，將從進風口進入之軸 向氣流轉向為沿該輪毅之徑向氣流後從出風口排出。組 裝時，該扇葉與扇框之頂面與底面之間通常需保證至少 1 ram左右之間隙，以防止扇葉轉動時與扇框產生摩擦。而 由於風扇運轉時其内部與進風口之間存在較大之氣壓差 ，容易使得該内部之高壓氣流依循該間隙回流到低壓之 進風口處而產生噪音，不利用風量之充分利用。並且， 氣流從進風口進入風扇内部之過程中，被風扇内部已經 加壓之氣流阻擋，使得進入氣流與回流氣流相互干擾， 影響風扇性能。 096149354 表單编號A0101 第3頁/共16頁 0993387336-0 1337643 099年10月27日按正替換頁 【發明内容】 [0004] 有鑒於此，有必要提供一種具有較小噪音、同時防止進 入氣流與風扇内高壓氣流之間產生相互干擾之離心風扇 〇 [0005] —種離心風扇，包括扇框及收容於扇框内之定子和轉子 ，該扇框包括頂板、底板及連接頂板與底板之側板，該 頂板和底板上至少其中之一形成有一入風口，該入風口 之周緣向扇框之内部環設有一擋風壁。 [0006] 與習知技術相比，通過於入風口之周緣設置一擋風壁， 該擋風壁可阻隔該風扇内之高壓氣流回流並從入風口洩 漏出去，從而減少從入風口進入氣流與風扇内高壓氣流 之間相互干擾，使得入風口進氣更容易吸入，同時提高 該離心風扇之進風之利用效率，達到降低噪音及增加風 量和風壓之目的。 【實施方式】 [0007] 如圖1及圖2所示，該離心風扇包括一扇框20、收容於該 扇框20内之一定子（圖未示）及相對於該定子旋轉之一 轉子40。 [0008] 該扇框20包括一頂板21、一底板22及連接於該頂板21及 底板22之間並與底板22 —體成型之側板23。該頂板21、 底板22與側板23共同形成一容置所述定子和轉子40之容 置空間。該扇框20之頂板21與底板22平行設置，分設於 該轉子40之上下兩侧。該頂板21與底板22之中央位置， 即正對轉子40之位置處分別形成圓形之上、下入風口 24a 、24b，該側板23於扇框20之一側形成一出風口 25，其 096149354 表單編號A0101 第4頁/共16頁 0993387336-0 1337643 货 · 099年ID月27日核正替换頁 中，該上入風口 24a之直徑大於下入風口 24b之直徑。一 擋風壁26沿下入風口 24b之周緣向上延伸一定高度形成， 該擋風壁26凸伸出底板22之頂面220，並環繞在下入風口 24b之周圍以形成一直徑大小基本上等於該下入風口 24b 之直徑大小之圓環柱形之進風通道。該擋風壁26之高度 大致為1.5mm (millimeter)，相當於將下入風口 24b 之位置上移1. 5mm至離心風扇内部，從而引導該下入風口 24b處之進風以垂直進入為主要方式。 [0009] 請一併參閱圖3，該轉子40包括一輪轂41、環設於該輪轂 41外圍之複數扇葉42及設於所述扇葉42遠離輪轂41之末 端之頂面並與其相互連接之一葉盤44。每一扇葉42包括 與輪轂41相連接之第一扇葉部422及高度大於該第一扇葉 部422之第二扇葉部424，其中，該第二扇葉部424與對 應之第一扇葉部422之末端為平滑連接，以減少該連接部 位對氣流之阻力，且該扇葉42之第一扇葉部422之下端與 第二扇葉部424之下端之相接部位正對擋風壁26之上方， 並與擋風壁26之頂面相隔大致0. 5mm之距離，以避免風扇 工作時扇葉42與擋風壁26之間產生磨擦。該第二扇葉部 424收容在該擋風壁26與扇框20之側板23之間，且該第 二扇葉部424於靠近擋風壁26之一侧與擋風壁26之間形成 大致為0.5min寬度之間隙，因而其高度不受擋風壁26高度 之限制，該第二扇葉部424之底端與扇框20之底板22之間 間隔1 mm左右之間隙。 [0010] 該葉盤44與扇葉42通過注塑方法一體成型。該葉盤44包 括一環形之頂壁441、從頂壁441外周緣垂直向下延伸之 096149354 表單編號A0101 第5頁/共16頁 0993387336-0 1337643 099年10月27日修正替換頁 呈環形之側壁442及從侧壁442之底端水準向外延伸之折 邊443。頂壁441收容於扇框20之上入風口 24a内，其上 表面與頂板21之上表面相平齊，其外徑之大小大致與扇 葉4 2之外徑相同且略小於上入風口 2 4 a之大小，且其内徑 之大小與下入風口 24b之大小大致相同。該葉盤44之頂壁 441覆蓋於扇葉42之上表面上，側壁442與第二扇葉部 424之最外側邊緣424a對齊並包覆於所述第二扇葉部424 之最外側邊緣424a之頂端之外圍，而折邊443則延伸至扇 框20之頂板21之内側邊緣之正下方，因此葉盤44取代一 部分扇框20覆蓋該上入風口 24a大於下入風口 24b之部分 ，可使原來直徑較大之上入風口 24a之實際入風面積減小 至基本上與下入風口 24b相等。為避免該離心風扇工作時 轉子40高速轉動與頂板21之間產生摩擦，該葉盤44之側 壁442 (即頂壁441之外周緣）與頂板21之上入風口 24a 處之内周緣之間及折邊443與頂板21之間分別間隔一微小 之間距。 [0011] 該葉盤44設置於扇框20之上入風口 24a内，頂壁441之位 置與該扇框20之頂板21之位置相齊平，扇葉42之第二扇 葉部424之頂端直接延伸至與該葉盤44之頂壁441連接成 一體，故，扇葉42與扇框20之頂板21之間沿軸向無需預 留間隙，從而可適當增加扇葉42之掃風截面高度。工作 時，轉子40高速轉動將上、下入風口 24a、24b進入之軸 向氣流轉向為沿輪毅41之徑向氣流，從而在扇葉4 2末端 與扇框20之側板23之間形成一高壓氣流通道。由於扇框 20之底板22上之擋風壁26之阻擋，風扇内之高壓氣流不 096149354 表單編號Λ0101 第6頁/共16頁 0993387336-0 13.37643 099年10月27日垵正替換頁 易經由該扇葉4 2之底端與扇框2 0之底板2 2之間形成之間 隙回流至下入風口 24b處而從該下入風口 24b洩漏出去。 並且該葉盤44之側壁442可視為設於上入風口 24a處之擋 風壁，由於該葉盤44之側壁442之阻擋，風扇内之高壓氣 流不易經由該葉盤44之折邊443與扇框20之頂板21之間 形成之間隙回流至上入風口處24a而從該上入風口 24a洩 漏出去。通過扇框20之底板22上擋風壁26及葉盤44之側 壁442防止風扇内之高壓氣流從其上、下入風口 24a、 24b洩漏出去，可提高該離心風扇之進風之利用效率，並 減少紊流，使得上、下入風口 24a、24b進氣更容易吸入 ，從而達到降低噪音及增加風量和風壓之目的。另外， 該扇框20之底板22上之擋風壁26將下入風口 24b之位置 上移至該風扇内部，從而引導下入風口 24b處之進風垂直 進入後即被扇葉42掃入高壓氣流通道内，使得進風順暢 ，減少在中途被高壓氣流之阻擋，進一步有利於達到降 低噪音及增加風量和風壓之目的。具體實施時，擋風壁 26之高度變化以於1. 5mm至2. 2mm之間變化為佳，當然也 可以根據具體情況進行調整。 [0012] 圖4所示為本發明離心風扇之第二實施例，其與上述第一 實施例之差別在於扇框20a之頂板2la上之上入風口 240a 之直徑與底板22a上之下入風口 240b之直徑相等，且葉盤 44a之結構與第一實施例中之葉盤44不同。具體而言，該 葉盤44a包括一環形之圓盤440a及從該圓盤440a之内周 緣垂直向上延伸之一環形之側壁442a。該圓盤440a與扇 葉42a上方之末端連接並位於扇框20a之頂板21a之下方 096149354 表單編號A0101 第7頁/共16頁 0993387336-0 1337643 099年10月27日核正替换頁 ，而側壁442a則向上延伸至與該扇框20a之頂板21a大致 相平。工作時，該側壁442a可視為設於該上入風口 240a 處之擋風壁，該側壁442a阻擋風扇内之高壓氣流經由葉 盤44a之頂壁44 0a之上方之間形成之間隙回流至上入風口 240a處而從該上入風口 240a洩漏出去，並能引導從上入 風口 240a處之進風以垂直進入為主要方式，達到降低噪 音及增加風量和風壓之目的。 [0013] 圖5所示為本發明離心風扇之第三實施例，其與上述第二 實施例之區別在於扇框2 0 b之頂板21 b之上入風口 2 4 2 a之 周緣向下延伸形成一擋風壁26b，而扇葉42b之頂端不設 置葉盤44a。該擋風壁26b之設置方式與及其作用方式均 同前所述，在此不贅述。 [0014] 綜上所述，本發明符合發明專利之要件，爰依法提出專 利申請。惟以上所述者僅為本發明之較佳實施例，舉凡 熟悉本案技藝之人士，在爰依本發明精神所作之等效修 飾或變化，皆應涵蓋於以下之申請專利範圍内。 【圖式簡單說明】 [0015] 圖1為本發明離心風扇一較佳實施例之組裝圖。 [0016] 圖2為圖1中離心風扇之分解圖。 [0017] 圖3為圖1中離心風扇沿11 I - I I I線之剖面示意圖。 [0018] 圖4為本發明離心風扇之第二實施例之剖面示意圖。 [0019] 圖5為本發明離心風扇之第三實施例之剖面示意圖。 【主要元件符號說明】 096149354 表單編號A0101 第8頁/共16頁 0993387336-0 1337643 099年10月27日垵正替換頁 [0020] 扇框：20、20a、20b [0021] 頂板：21、21a [0022] 底板：22 [0023] 頂面：22 0 [0024] 側板：23 [0025] 上入風口 ： 24a、240a、242a [0026] 下入風口 ： 24b、240b [0027] 出風口 ： 25 [0028] 擋風壁：26、2 6b [0029] 轉子：40 [0030] 輪轂：41 [0031] 扇葉：42、42a [0032] 第一扇葉：422 [0033] 第二扇葉：424 [0034] 邊緣：424a [0035] 葉盤：44、44a [0036] 頂壁：441、441a [0037] 側壁：442、442a [0038] 折邊：443 096149354 表單編號A0101 第9頁/共16頁 0993387336-0I337j543 _ October 27, 1999, the replacement page of the invention. 6. Description of the Invention: [Technical Field] [0001] The present invention relates to a centrifugal fan, and more particularly to a centrifugal fan suitable for heat dissipation of a notebook computer. [Prior Art] [0002] In recent years, with the development of the electronics industry, the performance of electronic components has been continuously improved, the computing speed has become faster and faster, and the heat dissipated during the work has increased accordingly. If these heats are not released in time, it will be extremely Affect the performance of electronic components, reduce the computing speed of electronic components, and burn out electronic components as heat accumulates. Therefore, electronic components must be dissipated, such as in a notebook computer, in a limited system space. A centrifugal fan that occupies less space is usually used for heat dissipation of electronic components. * [0003] The centrifugal fan generally includes a frame, a hub, and a plurality of blades extending radially outwardly around the hub, the fan frame having a top surface and a bottom surface respectively, a lower air inlet and a side surface One of the outlets. During operation, the fan air rotates to drive the surrounding air to flow, and the axial airflow entering from the air inlet is turned into a radial airflow along the wheel and then discharged from the air outlet. When assembling, it is usually necessary to ensure a clearance of at least 1 ram between the fan blade and the top surface and the bottom surface of the fan frame to prevent friction between the fan blade and the fan frame. However, due to the large air pressure difference between the inside and the air inlet when the fan is running, it is easy for the internal high-pressure airflow to follow the gap and return to the low-pressure air inlet to generate noise, and the full utilization of the air volume is not utilized. Moreover, during the process of the airflow entering the fan from the air inlet, the airflow that has been pressurized inside the fan is blocked, so that the incoming airflow and the return airflow interfere with each other, affecting the performance of the fan. 096149354 Form No. A0101 Page 3 / Total 16 Page 0993387336-0 1337643 October 27, 2008, by the replacement page [Invention] [0004] In view of this, it is necessary to provide a less noise while preventing the entry of airflow. A centrifugal fan that interferes with the high-pressure airflow in the fan. [0005] A centrifugal fan includes a fan frame and a stator and a rotor housed in the fan frame, the frame including a top plate, a bottom plate, and a side plate connecting the top plate and the bottom plate At least one of the top plate and the bottom plate is formed with an air inlet, and a peripheral wall of the air inlet is provided with a windshield wall to the inner ring of the fan frame. [0006] Compared with the prior art, a windshield wall is disposed on the periphery of the air inlet, and the windshield wall can block the high-pressure airflow in the fan from flowing back and leaking out from the air inlet, thereby reducing the airflow from the air inlet and the air inlet. The high-pressure airflow between the fans interferes with each other, so that the air intake of the air inlet is easier to inhale, and the utilization efficiency of the air inlet of the centrifugal fan is improved, thereby reducing the noise and increasing the air volume and the wind pressure. [Embodiment] As shown in FIG. 1 and FIG. 2, the centrifugal fan includes a frame 20, a stator (not shown) housed in the frame 20, and a rotor 40 rotated relative to the stator. . The frame 20 includes a top plate 21, a bottom plate 22, and a side plate 23 connected between the top plate 21 and the bottom plate 22 and integrally formed with the bottom plate 22. The top plate 21, the bottom plate 22 and the side plates 23 together form a receiving space for accommodating the stator and the rotor 40. The top plate 21 of the frame 20 is disposed in parallel with the bottom plate 22 and is disposed on the upper and lower sides of the rotor 40. The central position of the top plate 21 and the bottom plate 22, that is, the position facing the rotor 40, respectively form a circular upper and lower air inlets 24a, 24b. The side plate 23 forms an air outlet 25 on one side of the fan frame 20, and its 096149354 Form No. A0101 Page 4 / Total 16 Page 0993387336-0 1337643 Goods · In the 099 ID of the 27th nuclear replacement page, the diameter of the upper air inlet 24a is larger than the diameter of the lower air inlet 24b. A windshield wall 26 is formed to extend upwardly along a circumference of the lower air inlet 24b. The windshield wall 26 protrudes from the top surface 220 of the bottom plate 22 and surrounds the lower air inlet 24b to form a diameter substantially equal to the A circular cylindrical air inlet passage having a diameter of the lower air inlet 24b. The height of the windshield wall 26 is approximately 1.5 mm (millimeter), which is equivalent to shifting the position of the lower air inlet 24b upward by 1. 5 mm to the inside of the centrifugal fan, thereby guiding the inlet air at the lower air inlet 24b to enter vertically. the way. As shown in FIG. 3 , the rotor 40 includes a hub 41 , a plurality of blades 42 disposed around the periphery of the hub 41 , and a top surface of the blade 42 away from the end of the hub 41 and connected thereto. One of the leaf discs 44. Each of the blades 42 includes a first blade portion 422 coupled to the hub 41 and a second blade portion 424 having a height greater than the first blade portion 422, wherein the second blade portion 424 and the corresponding first portion The end of the blade portion 422 is a smooth connection to reduce the resistance of the connecting portion to the airflow, and the lower end of the first blade portion 422 of the blade 42 and the lower end of the second blade portion 424 are opposite each other. The distance between the fan blade 42 and the windshield wall 26 is avoided when the fan is in operation. The second blade portion 424 is received between the windshield wall 26 and the side plate 23 of the fan frame 20, and the second blade portion 424 is formed substantially adjacent to one side of the windshield wall 26 and the windshield wall 26. It is a gap of 0.5 min width, and thus its height is not limited by the height of the windshield wall 26. The bottom end of the second blade portion 424 is spaced apart from the bottom plate 22 of the fan frame 20 by a gap of about 1 mm. [0010] The leaf disc 44 and the blade 42 are integrally formed by an injection molding method. The leaf disc 44 includes an annular top wall 441 extending vertically downward from the outer periphery of the top wall 441. Form No. A0101 Page 5 / Total 16 pages 0993387336-0 1337643 October 27, 2017 Correction replacement page is ring-shaped The side wall 442 and the flange 443 extending outward from the bottom end of the side wall 442. The top wall 441 is received in the air inlet 24a above the fan frame 20, and the upper surface thereof is flush with the upper surface of the top plate 21, and the outer diameter of the outer wall is substantially the same as the outer diameter of the blade 4 2 and slightly smaller than the upper air inlet 2 It is 4 a in size and its inner diameter is approximately the same as the size of the lower air inlet 24b. The top wall 441 of the leaf disc 44 covers the upper surface of the blade 42 and the side wall 442 is aligned with the outermost edge 424a of the second blade portion 424 and covers the outermost edge 424a of the second blade portion 424. The periphery of the top end, and the flange 443 extends directly below the inner edge of the top plate 21 of the fan frame 20, so that the leaf disk 44 replaces a portion of the fan frame 20 to cover the portion of the upper air inlet 24a larger than the lower air inlet 24b. The actual air inlet area of the air inlet 24a having a larger diameter is reduced to be substantially equal to the lower air inlet 24b. In order to avoid friction between the high speed rotation of the rotor 40 and the top plate 21 during operation of the centrifugal fan, the side wall 442 of the leaf disc 44 (i.e., the outer periphery of the top wall 441) and the inner periphery of the air inlet 24a above the top plate 21 are The flange 443 and the top plate 21 are spaced apart by a slight distance. [0011] The leaf disc 44 is disposed in the air inlet 24a above the fan frame 20. The position of the top wall 441 is flush with the position of the top plate 21 of the fan frame 20, and the top of the second blade portion 424 of the fan blade 42 is provided. Directly extending to be integrated with the top wall 441 of the leaf disc 44, there is no need to reserve a gap between the blade 42 and the top plate 21 of the fan frame 20 in the axial direction, so that the height of the sweeping section of the blade 42 can be appropriately increased. . During operation, the rotor 40 rotates at a high speed to steer the axial airflow entering the upper and lower air inlets 24a, 24b into a radial airflow along the wheel 41, thereby forming a gap between the end of the blade 4 2 and the side panel 23 of the fan frame 20. High pressure air flow channel. Due to the blockage of the windshield wall 26 on the bottom plate 22 of the fan frame 20, the high pressure airflow in the fan is not 096149354. Form No. Λ0101 Page 6 / Total 16 pages 0993387336-0 13.37643 October 27, 2008, the replacement page is easy to pass A gap formed between the bottom end of the blade 4 2 and the bottom plate 22 of the frame 20 returns back to the lower air inlet 24b and leaks out from the lower air inlet 24b. The side wall 442 of the leaf disc 44 can be regarded as a windshield wall disposed at the upper air inlet 24a. Due to the blockage of the side wall 442 of the leaf disc 44, the high pressure airflow in the fan is not easily passed through the flange 443 and the fan of the leaf disc 44. The gap formed between the top plates 21 of the frame 20 is returned to the upper air inlet 24a and leaks out from the upper air inlet 24a. The windshield wall 26 of the bottom plate 22 of the fan frame 20 and the side wall 442 of the leaf disc 44 prevent the high-pressure airflow in the fan from leaking out from the upper and lower air inlets 24a, 24b, thereby improving the utilization efficiency of the air inlet of the centrifugal fan. The turbulence is reduced, so that the intake air of the upper and lower air inlets 24a, 24b is more easily sucked, thereby achieving the purpose of reducing noise and increasing air volume and wind pressure. In addition, the windshield wall 26 on the bottom plate 22 of the fan frame 20 moves the position of the lower air inlet 24b to the inside of the fan, so that the air entering the lower air inlet 24b is vertically scanned, and then the blade 42 is swept into the high voltage. In the airflow passage, the air inlet is smooth, and the middle air is blocked by the high-pressure airflow, which further helps to reduce noise and increase air volume and wind pressure. In the specific implementation, the change of the height of the windshield wall 26 is preferably between 1.5 mm and 2. 2 mm, and of course, it can be adjusted according to specific conditions. 4 is a second embodiment of the centrifugal fan of the present invention, which differs from the first embodiment in the diameter of the air inlet 240a above the top plate 21a of the fan frame 20a and the air inlet below the bottom plate 22a. The diameters of 240b are equal, and the structure of the leaf disc 44a is different from that of the leaf disc 44 in the first embodiment. Specifically, the leaf disc 44a includes an annular disk 440a and an annular side wall 442a extending vertically upward from the inner periphery of the disk 440a. The disc 440a is connected to the upper end of the fan blade 42a and is located below the top plate 21a of the fan frame 20a. 096149354 Form No. A0101 Page 7 / Total 16 Page 0993387336-0 1337643 On October 27, 2008, the replacement page is replaced, and the side wall The 442a extends upwardly to be substantially flush with the top plate 21a of the fan frame 20a. In operation, the side wall 442a can be regarded as a windshield wall disposed at the upper air inlet 240a, and the side wall 442a blocks the high pressure airflow in the fan from flowing back to the upper air inlet via a gap formed between the upper portions of the top wall 44a of the leaf disc 44a. At 240a, the upper air inlet 240a is leaked out, and the air entering from the upper air inlet 240a can be guided to enter vertically, which is the main way to reduce noise and increase air volume and wind pressure. [0013] FIG. 5 shows a third embodiment of the centrifugal fan of the present invention, which differs from the second embodiment in that the peripheral edge of the air inlet 2 4 2 a of the top plate 21 b of the fan frame 20 b extends downward. A windshield wall 26b is formed, and the tip end of the blade 42b is not provided with the leaf disc 44a. The arrangement of the windshield wall 26b and its mode of operation are the same as previously described, and will not be described herein. [0014] 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. BRIEF DESCRIPTION OF THE DRAWINGS [0015] FIG. 1 is an assembled view of a preferred embodiment of a centrifugal fan of the present invention. 2 is an exploded view of the centrifugal fan of FIG. 1. 3 is a schematic cross-sectional view of the centrifugal fan of FIG. 1 taken along line 11 I - I I I. 4 is a cross-sectional view showing a second embodiment of the centrifugal fan of the present invention. 5 is a cross-sectional view showing a third embodiment of the centrifugal fan of the present invention. [Description of main component symbols] 096149354 Form No. A0101 Page 8/Total 16 Page 0993387336-0 1337643 October 27, 2008, Yongzheng Replacement Page [0020] Fan Frame: 20, 20a, 20b [0021] Top Plate: 21, 21a [0022] Base plate: 22 [0023] Top surface: 22 0 [0024] Side plate: 23 [0025] Upper air inlet: 24a, 240a, 242a [0026] Lower air inlet: 24b, 240b [0027] Air outlet: 25 [ 0028] Windshield: 26, 2 6b [0029] Rotor: 40 [0030] Hub: 41 [0031] Fan blade: 42, 42a [0032] First blade: 422 [0033] Second blade: 424 [ 0034] Edge: 424a [0035] Leaf disc: 44, 44a [0036] Top wall: 441, 441a [0037] Side wall: 442, 442a [0038] Folding: 443 096149354 Form number A0101 Page 9 / Total 16 pages 0993387336 -0