現行電子產業迅速發展，電子元件之性能不斷提升，隨著運算速度越快其所產生之熱量則會相對產生較大之熱量，若無法將該熱量即時排出解熱，則該電子元件運算效能則會降低，嚴重者則會造成燒毀，故在有限的系統空間中透過離心風扇作為解熱使用。 請參閱第1、2A、2B圖式，習知的離心風扇1主要包含有一框體11及一扇葉12，該框體11的其上方111及下方112分別各具有一進風口13，其連接該上方111與下方112的側邊113具有一出風口14，且該上方111與下方112的進風口13所在的進風面13a是一樣大，並該側邊113分別與上方111與下方112相垂直，並該框體11內設有一容置空間114係容設該扇葉12，該扇葉12與側邊113之間形成有一流道15，該流道15與上方111的進風口13(或下方112的進風口13)所在的上方進風面13a (或下方進風面13a)相垂直。該扇葉12包含一輪轂121及複數葉片122設於該輪轂121的外側上，該等葉片122遠離該輪轂121的側邊1211與對應該框體11的上方111(或下方112)的上方進風面13a (或下方進風面13a)相垂直。所以當運轉時則透過該扇葉12的等葉片122旋轉帶動周圍空氣流動，將從進風口13進入之軸向氣流轉向沿該輪轂之徑向氣流後由出風口14排出。 而一般系統(如筆記型電腦、智慧型行動電話、車載系統、一體機(All-in-One，AIO)、迷你系統(mini system)或IPAD)內的離心風扇1尺寸在選擇上主要根據系統的最短邊高度地方來確認離心風扇1外形尺寸，但是對於不規則系統在選擇離心風扇1是很困難的，常出現二種情況:第一種情況是風扇尺寸選大時則會干涉系統內部的電子元件或其他裝置，例如不規則系統的最短邊高度可適合選用如3吋離心風扇，但又礙於與系統內部的電子元件或其他裝置(如散熱裝置或硬碟裝置)或系統外形相干涉，使得無法選用較適合尺寸的離心風扇來使用；第二種情況是因風扇尺寸選小會導致性能不夠(如風量不夠無法達到散熱需求)，使得如同虛設前述風扇，相當於浪費了容設前述風扇的系統空間，例如不規則系統受到內部的電子元件或其他裝置干涉的影響，使得只能選用如較小1吋離心風扇來使用，但由於1吋離心風扇吹出的風量不夠無法對整個系統快速散熱，以導致系統整體散熱性能不佳。The current electronic industry is developing rapidly, and the performance of electronic components is constantly improving. As the speed of operation increases, the heat generated by it will generate relatively large amounts of heat. If the heat cannot be immediately dissipated, the computing power of the electronic component will be If it is lowered, it will cause burnt, so it will be used as a heat release through a centrifugal fan in a limited system space. Referring to the first, second, and second embodiments, the conventional centrifugal fan 1 mainly includes a frame 11 and a blade 12. The upper portion 111 and the lower portion 112 of the frame 11 have an air inlet 13 respectively. The upper side 111 and the side 113 of the lower portion 112 have an air outlet 14 which is the same as the air inlet surface 13a where the air inlet 13 of the lower portion 112 is located, and the side edge 113 is opposite to the upper portion 111 and the lower portion 112, respectively. Vertically, the housing 11 is provided with an accommodating space 114 for accommodating the fan blade 12, and between the blade 12 and the side edge 113, a first-class channel 15 is formed, and the flow channel 15 and the air inlet 13 of the upper portion 111 ( The upper air inlet surface 13a (or the lower air inlet surface 13a) where the air inlet 13) of the lower portion 112 is located is perpendicular. The blade 12 includes a hub 121 and a plurality of blades 122 disposed on an outer side of the hub 121. The blades 122 are spaced apart from the side 1211 of the hub 121 and above the upper 111 (or lower 112) of the corresponding frame 11. The wind surface 13a (or the lower air inlet surface 13a) is perpendicular. Therefore, when operating, the surrounding air flows through the blades 122 of the blade 12 to drive the surrounding air to flow, and the axial airflow entering from the air inlet 13 is diverted from the radial airflow along the hub and then discharged from the air outlet 14. The size of the centrifugal fan 1 in a general system (such as a notebook computer, smart mobile phone, in-vehicle system, all-in-one (AIO), mini system or IPAD) is mainly selected according to the system. The shortest side height is used to confirm the size of the centrifugal fan 1, but it is very difficult to select the centrifugal fan 1 for the irregular system. There are two cases: the first case is when the fan size is large, it will interfere with the inside of the system. The shortest side height of an electronic component or other device, such as an irregular system, may be suitable for use with a centrifugal fan such as a 3-inch centrifugal fan, but interferes with the electronic components or other devices inside the system (such as heat sinks or hard disk devices) or the shape of the system. Therefore, it is impossible to use a centrifugal fan of a suitable size; in the second case, the selection of a small fan size may result in insufficient performance (for example, the air volume is insufficient to meet the heat dissipation requirement), so that the dummy fan is equivalent to wasting the foregoing. The system space of the fan, such as the irregular system, is affected by the interference of internal electronic components or other devices, so that only a small one can be selected. Fan is used, but because of the air volume of the centrifugal fan 1 inch blown not enough rapid cooling of the entire system, to result in poor overall system thermal performance.
本創作之上述目的及其結構與功能上的特性，將依據所附圖式之較佳實施例予以說明。 本創作係一種扇葉結構及離心風扇，請參閱第3A圖為本創作之第一實施例之扇葉結構之立體示意圖；第3B圖為圖3A之A-A剖面示意圖；第4A圖為本創作之第一實施例之扇葉結構之一實施態樣示意圖；第4B圖為本創作之第一實施例之扇葉結構之另一實施態樣示意圖。該扇葉結構2係應用於離心風扇3(如參考第5圖式)，該扇葉結構2包括一輪轂20及複數葉片21，該等葉片21環設於該輪轂20的外周側上，該每一葉片21具有一第一部分211及一第二部分212，該第一部分211與第二部分212之間具有一垂直延伸的虛擬直線L，該第二部分212從相鄰該虛擬直線L的第一部分211的一端向外延伸構成，於本實施例的該第一部分211的表面積大於該第二部分212的表面積，但並不侷限於此，於具體實施時，也可設計該第一部分211的表面積小於該第二部分212的表面積。 並該第一部分211具有一頂邊2111及一底邊2113，於本實施例表示該頂邊2111與底邊2113相平行，並該頂邊2111與該底邊2113的一端連接在該輪轂的外周側上，該頂邊2111與該底邊2113的另一端遠離該輪轂的外周側，該第二部分212具有一第一邊2121及一第二邊2122，該第一邊2121從該頂邊2111的另一端向外傾斜(如朝下向外傾斜)延伸連接該第二邊2122的一端，該第二邊2122的另一端連接水平相鄰的該底邊2113的另一端，並該虛擬直線L從該第一邊2121與該頂邊2111的另一端相接處向下垂直延伸至對應該底邊2113上，使該第二部分212的第一、二邊2121、2122與對應該虛擬直線L構成如三角形狀。其中由第3A圖可知，前述第一部分的表面積(或稱表面面積) 為該第一部分211的所有表面(包含頂邊2111表面、底邊2113表面及該第一部分211的二側面表面)的面積之和，該第二部分212的表面積(或稱表面面積)為該第二部分212的所有表面(包含第一、二邊2121、2122表面及該第二部分212的二側面表面)的面積之和。 在一實施例，參考第4A圖式，也可選擇設計該第一邊2121從該頂邊2111的另一端向外傾斜(如朝下向外傾斜)延伸連接該第二邊2122的一端，該第二邊2122的另一端傾斜連接相鄰的該底邊2113的另一端，且該第二部分212的第一、二邊2121、2122與對應該虛擬直線L構成如三角形狀。在另一實施例，參考第4B圖式，設計該第二部分212的第一、二邊2121、2122呈不規則的波浪狀。 並該每一葉片21設有一迎風面214與一對應該迎風面214的背風面215，該迎風面214與背風面215分別設於該葉片21的兩側，在該扇葉結構2運轉過程中(如逆時針旋轉)，該扇葉結構2朝向旋轉方向的一側面為迎風面214，另一側面為背風面215，且該迎風面214位於該背風面215的前方。另外，該迎風面214界定有一第一迎風面區2141及一從該第一迎風面區2141向外漸縮的第二迎風面區2142，該第一、二迎風面區2141、2142分別位於該第一、二部分211、212的一側面上，亦即該第一迎風面區2141位於該虛擬直線L與相對該輪轂20的外周側之間的第一部分211的一側面，該第二迎風面區2142則位於該虛擬直線L與相對該第一、二邊2121、2122之間的第二部分212的一側面，且該第一部分211的第一迎風面區2141的形狀與該第二部分212的第二迎風面區2142的形狀不相同，例如該第一部分211的第一迎風面區2141的形狀如為呈矩形狀，該第二部分212的第二迎風面區2142的形狀如為呈三角形狀，令前述葉片21整體形狀如為呈梯形狀，但前述葉片21的形狀並不以此為限。 該背風面215界定有一第一背風面區2151及一從該第一背風面區2151向外漸縮的第二背風面區2152，該第一、二迎風面區2141、2142分別對應該第一、二背風面區2151、2152，該第一、二背風面區2151、2152分別位於該第一、二部分211、212的另一側面上，該第一背風面區2151位於該虛擬直線L與相對該輪轂20的外周側之間的第一部分211的另一側面，該第二背風面區2152位於該虛擬直線L與相對該第一、二邊2121、2122之間的第二部分212的另一側面，且該第一部分211的第一背風面區2151的形狀與該第二部分212的第二背風面區2152的形狀不相同，例如該第一部分211的第一背風面區2151的形狀為如呈矩形狀，該第二部分212的第二背風面區2152的形狀為如呈三角形狀。 續參考第3A、3B圖，該輪轂20設有一連接部201，該連接部201設在該等葉片21的該底側213上，且該連接部201沿相對該輪轂20的外周側連接該等葉片21的底側213形成一環體，並該等葉片21之間形成有一葉片流道216，該葉片流道216用以將氣流(即空氣流體)朝該輪轂20的徑向方向流出，該兩兩葉片21之間的葉片流道216的形狀與面對的任一葉片21的形狀相同，如該每一葉片21的形狀如為呈梯形狀，此時位於兩兩葉片21之間的葉片流道216的形狀也會一樣如為呈梯形狀。 在一實施例，也可是設計該葉片21的形狀如為不規則形狀，此時位於兩葉片21之間的葉片流道216的形狀也會如為呈不規則形狀。在另一實施例，該輪轂20也可以省略掉該連接部201。 所以透過前述葉片流道216的形狀隨著葉片21的形狀變化而改變的結構設計，使該等葉片流道216可改變流出的氣流流場，讓氣流於該等葉片流道216內流出時更順暢地流出，進而有效提升風壓的效果。此外，藉由該等葉片21的第二迎風面區2142及第二背風面區2152有效增加了葉片21整體表面積及擴增葉片流道216面積，使得有效達到提升風量的效果。 因此，藉由本創作此扇葉結構2的設計，使得有效達到提升風量及風壓的效果，且還有效達到提升散熱的效果。 請參閱第5圖為本創作之第二實施例之扇葉結構之立體示意圖；第5A圖為圖5之B-B剖面示意圖；第5B圖為本創作之第二實施例之扇葉結構之一實施態樣示意圖；第5C圖為本創作之第二實施例之扇葉結構之另一實施態樣示意圖。該本實例的扇葉結構的結構及連結關係與前述第一實施例的扇葉結構及連結關係相同，故在此不重新贅述。本實施例主要是將前述第一實施例的第一部分211更包含一側邊2112，以及該第二部分212更包含一與第一、二邊2121、2122連接的第三邊2123，亦即該第一部分211具有前述頂邊2111、底邊2113及一側邊2112，該側邊2112的一端連接該頂邊2111的另一端，該第二部分212具有前述第一邊2121及第二邊2122及一與該第一、二邊2121、2122的一端連接的第三邊2123，該第一、二邊2121、2122的另一端分別連接該側邊2112的另一端與該底邊2113的另一端。其中由第5圖可知，前述第一部分211的表面積為該第一部分211的所有表面(包含頂邊2111表面、底邊2113表面、側邊2112表面及該第一部分211的二側面表面)的面積之和，該第二部分212的表面積為該第二部分212的所有表面(包含第一、二、三邊2121、2122、2123表面及該第二部分212的二側面表面)的面積之和。 並每一葉片21的迎風面214的第一迎風面區2141與第一背風面區2151分別位於該虛擬直線L與相對該輪轂20的外周側之間的第一部分211的一側面與另一側面，該第二迎風面區2142與第二背風面區2152分別位於該虛擬直線L與相對該第一、二、三邊2121、2122、2123之間的第二部分212的一側面與另一側面，且該第一部分211的第一迎風面區2141(或第一背風面區2151)的形狀與該第二部分212的第二迎風面區2142(或第二背風面區2152)的形狀不相同，例如該第一部分211的第一迎風面區2141(或第一背風面區2151)的形狀如為呈矩形狀，該第二部分212的第二迎風面區2142(或第二背風面區2152)的形狀如為呈矩形狀。而該兩兩葉片21之間的葉片流道216的形狀與面對的任一葉片21的形狀相同。 在一實施例，參考第5B圖，將該第一部分211的側邊2112之一端連接該頂邊2111的另一端改設計為該第一部分211的側邊2112之一端連接該底邊2111的另一端，且該第一、二邊2121、2122的另一端分別連接該頂邊2111的另一端與該側邊2112的另一端。 在另一實施例，參考第5C圖，該第一部分211的一側邊2112改設計包含二側邊2112，該二側邊2112的一端分別連接該頂邊2111與底邊2113的另一端，該第一、二邊2121、2122的另一端分別連接該二側邊2112的另一端。 因此，上述各實施例透過前述葉片流道216的形狀隨著葉片21的形狀變化而改變的結構設計，使該等葉片流道216可改變流出的氣流流場，讓氣流於該等葉片流道216內流出時更順暢地流出，進而有效提升風壓的效果。此外，藉由該等葉片21的第二迎風面區2142及第二背風面區2152有效增加了葉片21整體表面積及擴增葉片流道216面積，使得有效達到提升風量及風壓的效果，且還有效提升散熱效果。 請參閱第6圖為本創作之第三實施例之離心風扇之立體分解示意圖；第7A圖為本創作之第三實施例之離心風扇之立體組合示意圖；第7B圖為圖7A之C-C剖面示意圖，並輔以參閱第3A圖式。該離心風扇3包括一殼體31及一扇葉結構2，其中該扇葉結構2的結構及連接關係及功效與上述第一實施例的扇葉結構2的結構及連接關係及功效相同，故在此不重新贅述。並該殼體31於本實施例大致呈梯形狀說明，但不侷限於此，該殼體31設有一上蓋311、一底座312、一第一入風口315、一該第一入風口315所在的一第一入風面315a、至少一出風口317及一軸座313，該上蓋311係蓋設在該底座312上，且該上蓋311與該底座312共同界定一容置空間314，該容置空間314用以容設該軸座313及該扇葉結構2，該第一入風口315開設在該殼體31的上蓋311或底座312上，於本實施例的第一入風口315貫穿開設在該上蓋311上，且連通該容置空間314，該第一入風面315a與該上蓋311的外側在同一水平面上，該第一入風面315a與對應該等葉片21的第二部分212的第一邊2121不相垂直。 該底座312具有一底板3121及一從該底板3121上延伸的側壁3122，該軸座313設於該容置空間314內的底板3121之中央處，且與對應該扇葉結構2具有的一軸心23相樞設，並該扇葉結構2的輪轂20內具有一磁性件203與對應套設於該軸座313上的一定子33相感應激磁。該側壁3122於本實施例表示從相鄰該底板3121的周緣向上朝該容置空間314內傾斜延伸連接對應該上蓋311，該側壁3122的上端與對應該上蓋311的一側相連接，該殼體31的上蓋311與底板3121分別與該側壁3122不相垂直。而於本實施例的殼體31的側壁3122的截面形狀係與對應該等葉片21的第二部分212之第一邊2121的截面形狀相同，如殼體31的側壁3122的截面形狀與該等葉片21的第一邊2121的截面形狀皆呈同方向傾斜狀(或呈階梯狀或其他形狀)，使該殼體31的整體外形形成不規則狀。其中該上蓋311的表面積(即上蓋311的所有表面的面積之和)小於該底板3121的表面積(即底板3121的所有表面的面積之和)。 在替代實施例，可改設計所述殼體31的側壁3122的截面形狀與對應該等葉片21的第二部分212之第一、二邊2121、2122的截面形狀相同。 另外，該側壁3122上設有前述出風口317，該出風口317係連通該容置空間314，且用以將殼體31內的氣流排出，並該殼體31的側壁3122內側與面對該扇葉結構2的該等葉片21的第二部分212的一邊(如第一邊2121)之間形成有一外側空間318，該外側空間318與該第一入風口315所在的第一入風面315a不相垂直，且於本實施例的外側空間318之截面形狀呈傾斜狀(如第7B圖)，但並不侷限於此，於具體實施時，該外側空間318可隨該離心風扇3的殼體31外形形狀變化而改變形狀。所以透過本創作的離心風扇3應用於系統(如筆記型電腦、智慧型行動電話、車載系統、一體機(All-in-One，AIO)、迷你系統(mini system) 、智慧穿戴裝置或IPAD；圖中未示)內，使該離心風扇3的殼體31可隨系統變化而改變殼體31的外形形狀(如梯形狀)，進而該扇葉結構2的葉片21形狀(如梯形狀)與外側空間318的形狀(即外側空間318的截面形狀)也會隨著該殼體31的外形形狀變動而改變，使得有效達到離心風扇3結構靈活運用，以及可適用在各系統內，以充分利用系統內的空間。例如一系統內擺設該離心風扇3的放置空間較佳是選用尺寸大如4吋離心風扇3，但因離心風扇3的某部位(如離心風扇3的右上半部位)受到系統其內電子元件或其他裝置(如散熱器或硬碟)或系統外形的干涉，此時透過本創作的離心風扇3的殼體31外形形狀改變，如殼體31的側壁3122朝上蓋311方向往上向內傾斜及該上蓋311與該底板3121的表面積不同，藉以有效避掉受到干涉的部分，讓系統內仍可選用如4吋離心風扇3來獲得較佳散熱的效果，故可有效提升系統的性能。 該殼體31設有一對應該第一入風口315的第二入風口316及一該第二入風口316所在的一第二入風面316a，該第二入風口316貫穿開設在該底板3121上，且連通該容置空間314，並該第二入風面316a與該底板3121的外側在同一水平面上，該第二入風面316a不垂直該等葉片21的第二部分212的第一邊2121及該外側空間318，且於本實施例的第一入風面315a小於該第二入風面316a及第一入風口315小於該第二入風口316，但並不侷限於此。所以透過該上蓋311的第一入風面315a與對應該底板3121的第二入風面316a兩者的大小不同的設計，使得改善流場順暢度及有效達到提升風量的效果。 在替代實施例，可改設計該上蓋311表面積大於該底板3121的表面積，且第一入風面315a大於該第二入風面316，及該第一入風口315大於或小於該第二入風口316。 在另一替代實施例，參考第5A、5B、7B圖，將圖7B的殼體31的側壁3122截面形狀改設計大致呈階梯狀，令殼體31整體外形呈不規則狀，並該扇葉結構2改設計選用為前述第二實施例的扇葉結構2，令該外側空間318改設計形成在該殼體31的側壁3122內側與面對該等葉片21的第二部分212的第三邊2123與第一部分211的側邊2112之間，或是參考第5C、7B圖，將圖7B的殼體31的側壁3122截面形狀改設計大致呈凸狀，令殼體31整體外形呈不規則狀，而該外側空間318則改設計形成在該殼體31的側壁3122內側與面對該等葉片21的第二部分212的第三邊2123與第一部分211的二側邊2112之間，並該外側空間318與該第一、二入風面315a、316a不相垂直。 因此，藉由本創作的離心風扇3的結構設計，使得有效達到提升該離心風扇3的效率及達到提升散熱效果，且還有效解決習知的系統內無法選用適合尺寸的離心風扇的問題。The above object of the present invention, as well as its structural and functional features, will be described in accordance with the preferred embodiments of the drawings. The present invention is a fan blade structure and a centrifugal fan. Please refer to FIG. 3A for a perspective view of the blade structure of the first embodiment of the present invention; FIG. 3B is a schematic cross-sectional view of the AA of FIG. 3A; A schematic view of one embodiment of the blade structure of the first embodiment; FIG. 4B is a schematic view of another embodiment of the blade structure of the first embodiment of the present invention. The blade structure 2 is applied to the centrifugal fan 3 (refer to FIG. 5), the blade structure 2 includes a hub 20 and a plurality of blades 21, and the blades 21 are annularly disposed on the outer circumferential side of the hub 20, Each of the blades 21 has a first portion 211 and a second portion 212. The first portion 211 and the second portion 212 have a vertically extending virtual line L. The second portion 212 is adjacent to the virtual line L. One end of the portion 211 extends outwardly. The surface area of the first portion 211 in this embodiment is larger than the surface area of the second portion 212, but is not limited thereto. In a specific implementation, the surface area of the first portion 211 may also be designed. Less than the surface area of the second portion 212. The first portion 211 has a top edge 2111 and a bottom edge 2113. In this embodiment, the top edge 2111 is parallel to the bottom edge 2113, and the top edge 2111 and one end of the bottom edge 2113 are connected to the outer circumference of the hub. The second side 212 has a first side 2121 and a second side 2122 from the top side 2111. The other end of the second side 2122 is connected to the other end of the second side 2122, and the other end of the second side 2122 is connected to the other end of the horizontally adjacent bottom side 2113, and the virtual line L From the first side 2121 and the other end of the top edge 2111, vertically extending downwardly to the corresponding bottom edge 2113, so that the first and second sides 2121, 2122 of the second portion 212 and the corresponding virtual straight line L It is composed of a triangular shape. It can be seen from FIG. 3A that the surface area (or surface area) of the first portion is the area of all surfaces of the first portion 211 (including the surface of the top edge 2111, the surface of the bottom edge 2113, and the surface of the two sides of the first portion 211). And, the surface area (or surface area) of the second portion 212 is the sum of the areas of all surfaces of the second portion 212 including the first and second sides 2121, 2122 and the two side surfaces of the second portion 212. . In an embodiment, referring to FIG. 4A, the first side 2121 may be optionally designed to extend outwardly from the other end of the top edge 2111 (eg, inclined downwardly) to extend the end of the second side 2122. The other end of the second side 2122 is obliquely connected to the other end of the adjacent bottom edge 2113, and the first and second sides 2121, 2122 of the second portion 212 and the corresponding virtual straight line L are formed in a triangular shape. In another embodiment, referring to FIG. 4B, the first and second sides 2121, 2122 of the second portion 212 are designed to have an irregular wave shape. Each of the blades 21 is provided with a windward surface 214 and a pair of leeward faces 215 that are to face the windward surface 214. The windward surface 214 and the leeward surface 215 are respectively disposed on two sides of the blade 21, during the operation of the blade structure 2. (For example, counterclockwise rotation), one side of the blade structure 2 facing the rotation direction is the windward surface 214, and the other side is the leeward surface 215, and the windward surface 214 is located in front of the leeward surface 215. In addition, the windward surface 214 defines a first windward surface area 2141 and a second windward surface area 2142 that tapers outwardly from the first windward surface area 2141. The first and second windward surface areas 2141, 2142 are respectively located. One side of the first and second portions 211, 212, that is, the first windward surface area 2141 is located on a side of the first portion 211 between the virtual straight line L and the outer peripheral side of the hub 20, the second windward side The area 2142 is located on a side of the virtual line L and the second portion 212 between the first and second sides 2121, 2122, and the shape of the first windward surface area 2141 of the first portion 211 and the second portion 212 The shape of the second windward surface area 2142 is different. For example, the shape of the first windward surface area 2141 of the first portion 211 is rectangular, and the shape of the second windward surface area 2142 of the second portion 212 is triangular. The shape is such that the overall shape of the blade 21 is a trapezoidal shape, but the shape of the blade 21 is not limited thereto. The leeward surface 215 defines a first leeward surface area 2151 and a second leeward surface area 2152 that tapers outwardly from the first leeward surface area 2151. The first and second windward surface areas 2141, 2142 respectively correspond to the first And two leeward areas 2151, 2152, the first and second leeward areas 2151, 2152 are respectively located on the other side of the first and second parts 211, 212, and the first leeward area 2151 is located on the virtual straight line L and The second leeward region 2152 is located at the other side of the first portion 211 between the outer peripheral sides of the hub 20, and the second leeward region 2152 is located at the second portion 212 between the virtual line L and the first and second sides 2121, 2122. a side surface, and the shape of the first leeward surface area 2151 of the first portion 211 is different from the shape of the second leeward surface area 2152 of the second portion 212, for example, the shape of the first leeward surface area 2151 of the first portion 211 is The second leeward area 2152 of the second portion 212 has a triangular shape as in a rectangular shape. 3A and 3B, the hub 20 is provided with a connecting portion 201 which is provided on the bottom side 213 of the blades 21, and the connecting portion 201 is connected to the outer peripheral side of the hub 20. The bottom side 213 of the blade 21 forms a ring body, and a blade flow path 216 is formed between the blades 21 for flowing airflow (i.e., air fluid) toward the radial direction of the hub 20, the two The shape of the blade flow path 216 between the two blades 21 is the same as the shape of any of the facing blades 21, as the shape of each of the blades 21 is a trapezoidal shape, and the blade flow between the two blades 21 at this time is present. The shape of the track 216 will also be the same as a ladder shape. In an embodiment, the shape of the blade 21 may be designed to be irregular, and the shape of the blade flow path 216 between the two blades 21 may also be in an irregular shape. In another embodiment, the hub 20 can also omit the connecting portion 201. Therefore, through the structural design in which the shape of the blade runner 216 changes as the shape of the blade 21 changes, the blade runners 216 can change the flow field of the outgoing airflow, so that when the airflow flows out of the blade runners 216, Smoothly flow out, which effectively enhances the effect of wind pressure. In addition, the second windward surface area 2142 and the second leeward surface area 2152 of the blades 21 effectively increase the overall surface area of the blade 21 and expand the area of the blade flow path 216, so that the effect of increasing the air volume is effectively achieved. Therefore, by designing the blade structure 2, the effect of increasing the air volume and the wind pressure is effectively achieved, and the effect of improving the heat dissipation is effectively achieved. 5 is a schematic perspective view of a fan blade structure according to a second embodiment of the present invention; FIG. 5A is a schematic cross-sectional view taken along line BB of FIG. 5; and FIG. 5B is a schematic diagram of the blade structure of the second embodiment of the present invention. FIG. 5C is a schematic view showing another embodiment of the blade structure of the second embodiment of the present invention. The structure and the connection relationship of the blade structure of the present example are the same as those of the blade structure and the connection relationship of the first embodiment, and therefore will not be described again. In this embodiment, the first portion 211 of the first embodiment further includes a side 2112, and the second portion 212 further includes a third side 2123 connected to the first and second sides 2121, 2122. The first portion 211 has the top edge 2111, the bottom edge 2113 and the one side edge 2112. One end of the side edge 2112 is connected to the other end of the top edge 2111. The second portion 212 has the first side 2121 and the second side 2122. A third side 2123 connected to one end of the first and second sides 2121, 2122, the other ends of the first and second sides 2121, 2122 are respectively connected to the other end of the side 2112 and the other end of the bottom side 2113. As can be seen from FIG. 5, the surface area of the first portion 211 is the area of all the surfaces of the first portion 211 (including the top surface 2111 surface, the bottom side 2113 surface, the side 2112 surface, and the two side surfaces of the first portion 211). And, the surface area of the second portion 212 is the sum of the areas of all surfaces of the second portion 212 including the first, second, and third sides 2121, 2122, 2123 and the two side surfaces of the second portion 212. And the first windward surface area 2141 and the first leeward surface area 2151 of the windward surface 214 of each blade 21 are respectively located on one side and the other side of the first portion 211 between the virtual straight line L and the outer peripheral side of the hub 20 The second windward surface area 2142 and the second leeward surface area 2152 are respectively located on one side and the other side of the virtual line L and the second portion 212 between the first, second, and third sides 2121, 2122, and 2123. And the shape of the first windward surface area 2141 (or the first leeward surface area 2151) of the first portion 211 is different from the shape of the second windward surface area 2142 (or the second leeward surface area 2152) of the second portion 212. For example, the first windward surface area 2141 (or the first leeward surface area 2151) of the first portion 211 has a rectangular shape, and the second windward surface area 2142 of the second portion 212 (or the second leeward surface area 2152) The shape is as a rectangle. The blade runner 216 between the two blades 21 has the same shape as any of the blades 21 facing. In one embodiment, referring to FIG. 5B, the other end of the side edge 2112 of the first portion 211 is connected to the other end of the top edge 2111. The other end of the side edge 2112 of the first portion 211 is connected to the other end of the bottom edge 2111. The other ends of the first and second sides 2121, 2122 are respectively connected to the other end of the top edge 2111 and the other end of the side edge 2112. In another embodiment, referring to FIG. 5C, one side 2112 of the first portion 211 is modified to include two sides 2112, and one ends of the two sides 2112 are respectively connected to the other ends of the top edge 2111 and the bottom edge 2113. The other ends of the first and second sides 2121, 2122 are respectively connected to the other ends of the two side edges 2112. Therefore, the above embodiments are designed such that the shape of the blade runner 216 changes as the shape of the blade 21 changes, so that the blade runners 216 can change the flow field of the outgoing airflow, allowing the airflow to flow through the blade runners. When flowing out in 216, it flows out more smoothly, which effectively increases the effect of wind pressure. In addition, the second windward surface area 2142 and the second leeward surface area 2152 of the blades 21 effectively increase the overall surface area of the blade 21 and expand the area of the blade flow path 216, so that the effect of increasing the air volume and the wind pressure is effectively achieved, and It also effectively improves the heat dissipation effect. 6 is a perspective exploded view of a centrifugal fan according to a third embodiment of the present invention; FIG. 7A is a perspective view showing a three-dimensional combination of the centrifugal fan of the third embodiment; FIG. 7B is a schematic cross-sectional view of the CC of FIG. And supplemented by referring to Figure 3A. The centrifugal fan 3 includes a casing 31 and a blade structure 2, wherein the structure, connection relationship and function of the blade structure 2 are the same as those of the blade structure 2 of the first embodiment, I will not repeat them here. The housing 31 is substantially ladder-shaped in this embodiment, but is not limited thereto. The housing 31 is provided with an upper cover 311, a base 312, a first air inlet 315, and a first air inlet 315. a first air inlet surface 315a, at least one air outlet 317, and a shaft seat 313. The upper cover 311 is disposed on the base 312, and the upper cover 311 and the base 312 define an accommodating space 314. The first air inlet 315 is disposed on the upper cover 311 or the base 312 of the housing 31, and the first air inlet 315 of the embodiment is opened therethrough. The upper cover 311 is connected to the accommodating space 314. The first air inlet surface 315a is on the same horizontal plane as the outer surface of the upper cover 311. The first air inlet surface 315a and the second portion 212 corresponding to the blade 21 are corresponding. One side 2121 is not vertical. The base 312 has a bottom plate 3121 and a side wall 3122 extending from the bottom plate 3121. The shaft base 313 is disposed at the center of the bottom plate 3121 in the accommodating space 314 and has an axis corresponding to the fan blade structure 2. The core 23 is pivoted, and a magnetic member 203 is formed in the hub 20 of the blade structure 2 to be magnetized with a stator 33 corresponding to the shaft seat 313. In the embodiment, the side wall 3122 is obliquely extended from the periphery of the adjacent bottom plate 3121 toward the accommodating space 314. The upper end of the side wall 3122 is connected to the side corresponding to the upper cover 311. The upper cover 311 and the bottom plate 3121 of the body 31 are not perpendicular to the side wall 3122, respectively. The cross-sectional shape of the side wall 3122 of the housing 31 of the present embodiment is the same as the cross-sectional shape of the first side 2121 of the second portion 212 corresponding to the blade 21, such as the cross-sectional shape of the side wall 3122 of the housing 31 and the like. The cross-sectional shape of the first side 2121 of the blade 21 is inclined in the same direction (or stepped or other shape), so that the overall shape of the casing 31 is irregular. The surface area of the upper cover 311 (ie, the sum of the areas of all surfaces of the upper cover 311) is smaller than the surface area of the bottom plate 3121 (ie, the sum of the areas of all surfaces of the bottom plate 3121). In an alternative embodiment, the cross-sectional shape of the side wall 3122 of the housing 31 can be modified to be the same as the cross-sectional shape of the first and second sides 2121, 2122 of the second portion 212 of the corresponding blade 21. In addition, the side wall 3122 is provided with the air outlet 317, and the air outlet 317 is connected to the accommodating space 314, and is used for discharging the airflow in the casing 31, and the inner side of the side wall 3122 of the casing 31 faces the surface. An outer space 318 is formed between one side (such as the first side 2121) of the second portion 212 of the blade 21 of the blade structure 2, and the outer space 318 and the first air inlet surface 315a where the first air inlet 315 is located It is not perpendicular, and the cross-sectional shape of the outer space 318 in this embodiment is inclined (as shown in FIG. 7B), but is not limited thereto. In a specific implementation, the outer space 318 may follow the shell of the centrifugal fan 3. The shape of the body 31 changes and the shape changes. Therefore, the centrifugal fan 3 of the present invention is applied to the system (such as a notebook computer, a smart mobile phone, an in-vehicle system, an all-in-one (AIO), a mini system, a smart wearable device or an IPAD; The housing 31 of the centrifugal fan 3 can change the outer shape (such as the trapezoidal shape) of the housing 31 as the system changes, and the shape of the blade 21 (such as the ladder shape) of the blade structure 2 is The shape of the outer space 318 (i.e., the cross-sectional shape of the outer space 318) also changes as the outer shape of the outer casing 31 changes, so that the centrifugal fan 3 structure can be effectively utilized and can be applied to each system to make full use of it. The space within the system. For example, the space for arranging the centrifugal fan 3 in a system is preferably a centrifugal fan 3 having a size as large as 4 ,, but a certain part of the centrifugal fan 3 (such as the upper right half of the centrifugal fan 3) is subjected to electronic components in the system or The interference of other devices (such as a heat sink or a hard disk) or the shape of the system, at this time, the shape of the casing 31 of the centrifugal fan 3 of the present invention is changed, for example, the side wall 3122 of the casing 31 is inclined upward and upward toward the upper cover 311 and The upper cover 311 and the bottom plate 3121 have different surface areas, so as to effectively avoid the interference, so that the system can still use the centrifugal fan 3 to obtain better heat dissipation, so that the performance of the system can be effectively improved. The housing 31 is provided with a pair of second air inlets 316 that should be the first air inlet 315 and a second air inlet surface 316a of the second air inlet 316. The second air inlet 316 is opened on the bottom plate 3121. And accommodating the accommodating space 314, and the second air inlet surface 316a is on the same horizontal plane as the outer side of the bottom plate 3121, and the second air inlet surface 316a is not perpendicular to the first side of the second portion 212 of the blades 21. 2121 and the outer space 318, and the first air inlet surface 315a of the embodiment is smaller than the second air inlet surface 316a and the first air inlet 315 is smaller than the second air inlet 316, but is not limited thereto. Therefore, the design of the first wind inlet surface 315a of the upper cover 311 and the second air inlet surface 316a corresponding to the bottom plate 3121 are different in size, so that the flow field smoothness is improved and the effect of increasing the air volume is effectively achieved. In an alternative embodiment, the surface of the upper cover 311 is larger than the surface area of the bottom plate 3121. The first air inlet surface 315a is larger than the second air inlet surface 316, and the first air inlet 315 is larger or smaller than the second air inlet. 316. In another alternative embodiment, referring to FIGS. 5A, 5B, and 7B, the cross-sectional shape of the side wall 3122 of the casing 31 of FIG. 7B is modified to be substantially stepped, so that the overall shape of the casing 31 is irregular, and the blade is The structure 2 is modified to select the blade structure 2 of the second embodiment, and the outer space 318 is modified to be formed on the inner side of the side wall 3122 of the casing 31 and the third side facing the second portion 212 of the blades 21. 2123 and the side 2112 of the first portion 211, or with reference to the 5C, 7B, the cross-sectional shape of the side wall 3122 of the housing 31 of FIG. 7B is substantially convex, so that the overall shape of the housing 31 is irregular. The outer space 318 is modified to be formed between the inner side of the side wall 3122 of the casing 31 and the third side 2123 of the second portion 212 facing the blades 21 and the two sides 2112 of the first portion 211, and The outer space 318 is not perpendicular to the first and second air inlet surfaces 315a, 316a. Therefore, with the structural design of the centrifugal fan 3 of the present invention, the efficiency of the centrifugal fan 3 can be effectively improved and the heat dissipation effect can be improved, and the problem that the centrifugal fan of a suitable size cannot be selected in the conventional system can be effectively solved.