200810667 • 九、發明說明： v【發明所屬之技術領域】 本發明係有關於一種導風罩，更詳言之，係有關於_ 種用以將散熱風扇之氣流導引至發熱裝置之導風罩。 【先前技術】 、冑著電子科技不斷的進步與發展，電子設備已成為人 犬員生活中不可或缺的—部份，然而電子設備中又以電腦的 龜應用最為廣泛，且電腦中有許多主要電子組件，而眾多電 子組件中又以主機板設置的電子元件是最多的，隨著電子 设備之功能不斷地增加及提昇，其所裝設之電子元件亦越 來越多，然而，當該電子設備運作時，該電子組件及元件 亦會產生熱能，故，如何使該電子組件及元件在運作時所 產生之熱能能夠充分散熱，而使該電子組件及元件不會因 產生過熱而造成該電子設備運作不穩，是目前電子設備所 面臨的棘手問題。 • 應用於電子設備的散熱裝置絕大部份是裝設複數個 _風扇來對電子設備内部的電子組件及元件提供熱對流之 散熱效果，而電子設備的内部空間有限，亦無法裝設過多 的風扇進行熱對流，且電子設備内部各組件及元件配置相 當始、集，該對流空氣難以通過所有電子組件及元件，或是 通過各組件及元件的流量不一，導致部份組件及元件之散 熱效果不彰，特別是中央處理器及記憶體等高發熱元件。 备包子设備全時工作下若未能提供足夠且連續的對流冷 空亂對兩熱元件進行熱對流，易因上述高發熱元件過熱而 19545 5 200810667 &成内部零組件燒毀或者當機的情形。 =閱第！圖，伺服ϋΜ中係具有接置Μ央處理單 之散熱塊體1〇及記憶體單元U，而為了散 吁、处理早70及記憶體單元u因運作而產生的埶能， U並具有散熱風扇12其所產生的氣流;;直接 ::4熱塊體10，而剩餘之氣流則越過該散熱塊體1〇 ^鄞至該記憶體單元11。 # 中央處理單元及記憶體單幻i於伺服器i中配置之 量主要在於中央處理器為主要發歸置而該記憶體單 2 11則為次發熱裝置，因此必須將主要發熱裝置設於最 ，散熱風扇12之處以直接接收風力最強且最低溫之散 ”、、氣〇 一惟，記憶體單元11之發熱量雖不及於該中央處理單 70，然而長期運作下所產生的熱能亦十分可觀，當伺服器 :具_有寬闊的内部空間時，記憶體單元n所產生的熱能 可藉由自然的熱對流而降溫，然而當伺服器丨為厚度單位 _為之伺服器時’記憶體單元丨丨將會有熱對流不及的現 象，而散熱氣流亦因伺服器i内部空間的狹小而難以流動 至记憶體單元11，因而容易使記憶體單元丨丨過熱。 ^ 後來有人提出一種罩覆該散熱塊體10之導風罩以將 ，熱風扇12之氣流導引至該記憶體單元u，然而當伺服 态1為1U伺服器時，中央處理單元上之散熱塊體1〇已接 近於忒伺服器1之頂面而阻撞了大部份的氣流，而所能流 動至#憶體單元11之氣流均為先行與該散熱塊體丨〇上之 19545 6 200810667 •散熱鰭片熱對流過後之高温氣流，因此該導風罩僅能略為 v加強並集中散熱風扇之氣流而對於提升記憶體單元丨丨之 散熱效果並無明顯功效。 另外，伺服器1中之記憶體單元11係為多條並列， 而導致位於中央區域的記憶體容易產生聚熱的現象，即使 散熱氣流可流動至該記憶體單元U，亦不易將記憶體單 元11中央區域之熱能散逸。 因此，如何研發一種新的技術以改善上述缺點，實為 馨業界亟待克服之課題。 、 【發明内容】 鑒於以上所述習知技術之缺點，本發明之一目的在於 提供一種導風罩’俾使受主發熱裝置阻擋之次發熱裝置可 具有良好的散熱效果。 本發明之次-目的在於提供—種導風罩，俾散逸記憶 月豆早70中央區域之熱能。 為達上述及其它目的，本發明提供一種導風罩，係腐 用t一内部至少具有呈縱向依序設置之散熱風扇、第-發 熱裝置以及第二發熱裝置之雷 复又毛子彡又備，其中該電子設備具 有 上盘’该導風罩包相^ · 一 -y-, •一I板，至少蓋覆於該第一發 熱叙置，並於對應該第—筱种 乐發熱裝置之位置設有一導風開 口，以及複數個側板，接f 罝於σ亥盍板之相對兩侧，該4b側 板與該蓋板構成一第一塌t 一、 > 、逼，该蛉風開口與該上蓋構成一 弟二通道，該散熱風扇之气、六於γ丄 咏 虱流係經由該第一通道而散逸該 弟一發敎裝置之孰能，分 ，、、、衣 4散熱風扇之氣流並可經由該第二 19545 7 200810667 二發熱裝置之熱 •通道導引至該第二發熱裝置，俾散逸該第 該電子設備可為厚度單位為u之舰器。該第一發 =置可為接置於中央處理器（CPU)上的散熱塊體，而 p二發熱裝置則可為記憶體單元（細）。該導風罩於相 j兩端分別構成-人風σ及—第—出風σ，該人風口及該 弟一出風口分別與該第—通料通，俾使該導風罩以該入 ，口將氣流導人該第-通道，並以該第—出風口將氣流導 出〇 相幸乂方、白知技術中記憶體單元受到 阻播散熱氣流而有散熱效能不佳之缺點，本發明之 f風罩 口 -有導風開口而使得散熱氣流得以由該第二通道導引 e該第二發熱單元，使該第二發熱裝置因接收到足量且低 溫之氣流而可迅速地散逸熱量。 壯該導風罩係軍覆該第一發熱裝置及部份之第二發熱 =置’而該導風開口係至少涵蓋該第—發熱裝置，較佳地 7風開π係延伸至該第二發熱裝置上方。該蓋板復可設 有":連通於該第—出風口之通風缺口，該通風缺π係至少 涵盍該第二發熱裝置之中央區域以減少該中央區域之風 :：使集中於該中央區域之熱能可迅速地散逸而出，一 般而言第—出風口係接近電子設備後方之通風開口， 因此亦可藉由外部之冷空氣流人該通風缺口而進一步地 第二發歸置中央區域之熱能。相較於習吨術記 〜心早兀之中央區域容易積熱的現象，本發明之導風罩因 19545 8 200810667 :缺口而可快速地將第二發熱裝置（記憶體單元) 中央區域之熱能散逸而出。 早7°) 、另卜々广導風罩復具有一相對於該入風口且導通該第 通道之第一出風口，且該電子設備於該第—發熱裝° (散熱塊體）旁復可設有一第^ *''' -中本卢η广 裝置其亦可為接置於 央处里早7L (CPU)上之散熱塊體。 由上可知，本發明之導風罩可改善習知缺點 有高度產業利用價值。 H、 【實施方式】 以下係猎由特定的具體實例說明本發明之實施方 人士可由本說明書所揭示之内容輕易地 瞭解本發明之其他優點與功效。 以下第2Α圖至第2C：圖係說明本發明之導風罩之一較 佳具體實施例。 :=第以圖’本發明所提供之導風罩3係應用於 至>具有讀向依序設置之散熱風扇2Q、第_發熱裝置 21及第二發熱裝置22之 係用以散逸該第一、二該散熱風扇 … ^…、衣置所產生的熱能，本發 之導風罩3係包括·盍板3()，至少蓋覆於該第一發軌 〔;置=，並於對應該第一發熱褒置21之位置設有一導風 開口 3〇1 ;以及複數個側板33，接置於該蓋板3〇之相對 兩側，該些侧板33與該蓋板3〇並構成-第-通道34。 該導風罩3於相對兩端分別具有-入風口 31及-第-出 風口 32，該人風口 31及該第1風口 32分別與該第- 19545 9 200810667 通道34連通，俾使該導風罩3以該入風口 31將氣流導入 該第一通道35,並由該第一出風口 32將氣流導出，以散 逸該第一發熱裝置21之熱能。此外，該蓋板3〇於上方靠 近該導風開口 301之邊緣係設有氣密膠條3〇2。 該電子設備2可為厚度單位為1LJ之伺服器，該第一 發熱裝置21可為接置於中央處理單元（cpu)上之散熱塊 Μ ’而該第二發熱裝置22則可為複數並列之記憶體單元 (RAM)。然而該電子設備2、第一發熱裝置2卜以及第二 發熱I置22 ϋ非以上所述者為限，而可加以變化，而該 等變化係為熟悉本發明領域者所能思及並加以應用，例如 =子設備2可為料舰器之刀鋒㈣，該第一發熱裳 1可為硬碟模組，而該第二發熱裝置22可為工作晶片 體）旁復可設有二 弟一發熱震置21 (散熱塊 弟—發熱裝置23其亦可為接置於一中 .央處理單元（CPU，同去一、 Τ -備2可為-且有之散純體，即該電子設 風罩3復可执有:一 /处理早凡之1U <司服器，因此該導 道34之第一°又出n 對於該入風口 31且導通該第一通 之弟一出風口 35，並佶兮笙-八也莊如 該入風口 3i及該第二㈣弟二务熱装置23容納於 之氣流亦可用於散逸該二'35之間，俾使散熱風扇20 熱能。 、月、ϋ熱裝置23運轉時所產生的 請配合參閱第2β 24,該第一發哉壯署子故備2係具有-上蓋 …、衣置21係透過該導風開口 3〇1與該上蓋 19545 10 200810667 =成-第二通道36，使該散熱風扇2〇運轉所形成之氣 二=入風口 31進入第一通道34後分為吹拂於該第-發熱衣置21之氣流A1及經由該第一福# 、.， 第二發熱裝置22之氣流A2。通道36而導引至該 ，相較於習知技術中記憶體單元受到咖的散熱塊體 阻擋散熱氣流而有散熱效能不佳之缺點，本發明之導風罩 3因具有導風開σ 3Q1而使得氣流A2得以由該第二通道 36導引至該第二發熱裝置22以迅速散逸其產生之熱能。 該蓋板30係蓋覆該第一發熱裝置21並蓋覆部份之該 第二發熱裝置，且該導風開口 3〇1係至少涵蓋該第—料 裝置2卜較佳地該導風開口 3〇1可延伸至該第二發熱裝 置22上方’以利於將氣流A2導引至該第二發熱裝置μ。 此外，設於該蓋板30上之氣密膠條3〇2係密接於該 電子設備2之上蓋24而使氣流八2集中導引至該第二發°熱 裝置22 ’以避免氣流A2散逸至電子設備2中而影響對於 _该弟一發熱裝置22之散熱效果。 、 覆請配合參閱第2C圖，由前述可知該電子設備2可 具有一設於該第一發熱裝置21旁的第三發熱裝置23其亦 仰賴5亥政熱風扇20進行散熱，惟該第一發熱裝置Μ後方 没有第二發熱裝置22，因此散熱風扇2〇所產生的氣流A 必須有較多的比例導引至該第一發熱裝置21，是以可^ 該i板30下方靠近該入風口 31處設有可將大部份_^散熱氣 流A導引至該第一發熱裝置21之導流板3〇3，而當電子& 設備2未增設有第三發熱裝置23時，可於該蓋板下方 19545 11 200810667 接置-遮擔板304,該遮擒板3〇4係用以遮 %以使氣流A集中流向該第一發熱裝置；風口 與散熱氣流A之行進方向可呈一 遮狯板304200810667 • IX. Description of the invention: v [Technical field to which the invention pertains] The present invention relates to an air hood, and more particularly, to a wind guide for guiding a flow of a cooling fan to a heat generating device cover. [Prior Art] With the continuous advancement and development of electronic technology, electronic equipment has become an indispensable part of human dog life. However, computerized turtles are the most widely used in electronic devices, and there are many computers. The main electronic components, and among the many electronic components, the electronic components set by the motherboard are the most. As the functions of electronic devices continue to increase and increase, more and more electronic components are installed. However, when When the electronic device is in operation, the electronic components and components also generate heat energy, so how to heat the heat generated by the electronic components and components during operation, so that the electronic components and components are not caused by overheating. The unstable operation of the electronic device is a thorny problem facing electronic devices. • The majority of heat sinks used in electronic devices are equipped with a number of fans to provide heat dissipation to the electronic components and components inside the electronic device. The internal space of the electronic device is limited and cannot be installed too much. The fan performs thermal convection, and the components and components in the electronic device are arranged and assembled. The convective air is difficult to pass through all the electronic components and components, or the flow rate of each component and component is different, resulting in heat dissipation of some components and components. The effect is not good, especially high-heat components such as central processing unit and memory. If the sub-package equipment fails to provide sufficient and continuous convection cold air to convect the two heat elements under full-time operation, it is easy to overheat due to the overheating of the above high-heat components. 19545 5 200810667 & into internal components burned or crashed situation. = read the first! In the figure, the servo 具有 has a heat sink block 1 〇 and a memory unit U connected to the central processing unit, and the heat is generated in order to dissipate, process the early 70 and the memory unit u due to operation. The airflow generated by the fan 12; directly: 4 thermal block 10, and the remaining airflow passes over the thermal block 1 to the memory unit 11. # The central processing unit and the memory single illusion i are arranged in the server i mainly because the central processing unit is the primary transmission and the memory unit 2 11 is the secondary heating device, so the main heating device must be set at the most The heat-dissipating fan 12 directly receives the strongest and lowest temperature of the wind, and the heat of the memory unit 11 is not as good as that of the central processing unit 70. However, the heat generated by the long-term operation is also considerable. When the server: has a wide internal space, the thermal energy generated by the memory unit n can be cooled by natural thermal convection, but when the server is a thickness unit _ for the server, the memory unit丨丨 There will be a phenomenon of thermal convection, and the heat dissipation airflow is difficult to flow to the memory unit 11 due to the narrow space inside the server i, so that it is easy to overheat the memory unit. ^ Later, a cover was proposed. The air hood of the heat dissipation block 10 guides the airflow of the heat fan 12 to the memory unit u. However, when the servo state 1 is a 1U server, the heat dissipation block body on the central processing unit has been Close to the top surface of the servo server 1 and blocking most of the airflow, and the airflow that can flow to the #memory unit 11 is first and the heat sink block is attached to the 19545 6 200810667 • heat sink fins The high temperature airflow after the heat convection, so that the air hood can only slightly strengthen and concentrate the airflow of the cooling fan, and has no obvious effect on improving the heat dissipation effect of the memory unit. In addition, the memory unit 11 in the server 1 There are a plurality of parallel lines, and the memory located in the central area is prone to heat accumulation. Even if the heat dissipation airflow can flow to the memory unit U, it is difficult to dissipate the heat energy in the central area of the memory unit 11. Therefore, how to develop A new technology to improve the above-mentioned shortcomings is an urgent problem to be overcome in the industry. [Invention] In view of the above disadvantages of the prior art, it is an object of the present invention to provide an air hood that causes the recipient to heat up. The secondary heat-generating device blocked by the device can have a good heat-dissipating effect. The second aspect of the present invention is to provide a wind deflector, which is a central area of 70 In order to achieve the above and other objects, the present invention provides an air hood that is provided with at least a heat dissipating fan, a first heat generating device, and a second heat generating device, which are disposed in the longitudinal direction. Further, the electronic device has an upper tray 'the air hood cover ^ · a-y-, an I board, at least covered by the first heat generation, and corresponding to the first 筱 筱 发热 fever The position of the device is provided with a wind guide opening, and a plurality of side plates are connected to opposite sides of the σ 盍 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , The opening and the upper cover form a second channel, and the air-dissipating fan of the cooling fan is dissipated through the first channel to dissipate the heat, fan, and air cooling fan of the hairpin device. The airflow can be guided to the second heat generating device via the heat channel of the second 19545 7 200810667 heat generating device, and the electronic device can be a ship of thickness u. The first hair can be a heat sink block attached to a central processing unit (CPU), and the p heat generating device can be a memory unit (thin). The air hood is respectively formed on the two ends of the phase j - a human wind σ and a first air σ, and the air outlet and the air outlet of the younger are respectively connected with the first air outlet, so that the air hood is inserted into the air hood The mouth guides the airflow to the first passage, and the airflow is led out by the first air outlet, and the memory unit is blocked by the heat dissipation airflow, and the heat dissipation performance is poor. f hood opening - having an air guiding opening to allow the venting air to be guided by the second channel e to the second heat generating unit, so that the second heat generating device can quickly dissipate heat due to receiving a sufficient amount of low temperature airflow. The windshield covers the first heat generating device and a portion of the second heat generating device, and the air guiding opening covers at least the first heat generating device, preferably 7 wind opening π system extends to the second Above the heating device. The cover plate may be provided with a ventilation gap that is connected to the first air outlet, and the ventilation shortage π is at least a central area of the second heat generating device to reduce the wind of the central area: The heat energy in the central area can be quickly dissipated. Generally, the first air outlet is close to the ventilation opening behind the electronic device, so that the second cold hair can be further placed centrally by the external cold air flowing through the ventilation gap. The heat of the area. Compared with the phenomenon that the central area of the smear is easy to accumulate heat, the air hood of the present invention can rapidly heat the central area of the second heat generating device (memory unit) due to the gap of 19545 8 200810667: Dissipate. 7°), the other 々 々 导 导 具有 has a first air outlet that is opposite to the air inlet and that opens the first channel, and the electronic device is replenished by the first heating element (heat block) It has a ^*'''-Zhongbenlu η wide device, which can also be a heat sink block that is placed on the 7L (CPU) in the central office. As can be seen from the above, the air hood of the present invention can improve the conventional disadvantages and has high industrial utilization value. H. [Embodiment] The following description of the present invention will be readily understood by those skilled in the art from this disclosure. The following Figures 2 to 2C are diagrams showing a preferred embodiment of the hood of the present invention. The air hood 3 provided by the present invention is applied to the heat dissipating fan 2Q, the first heat generating device 21 and the second heat generating device 22 which are provided in the reading direction for dissipating the first One or two of the cooling fans... ^..., the thermal energy generated by the clothes, the windshield 3 of the present invention includes a slab 3 (), at least covering the first track [; set =, and in the right A wind guide opening 3〇1 is disposed at a position of the first heat generating device 21; and a plurality of side plates 33 are disposed on opposite sides of the cover plate 3, and the side plates 33 and the cover plate 3 are formed and configured - No. - channel 34. The air hood 3 has an air inlet 31 and a first air outlet 32 at opposite ends. The air vent 31 and the first air vent 32 are respectively connected to the -19545 9 200810667 channel 34, so that the air guiding is performed. The cover 3 introduces the airflow into the first passage 35 through the air inlet 31, and the airflow is led out by the first air outlet 32 to dissipate the heat energy of the first heat generating device 21. In addition, the cover plate 3 is provided with a gas-tight adhesive strip 3〇2 at the edge of the wind guide opening 301. The electronic device 2 can be a server having a thickness unit of 1 LJ, the first heat generating device 21 can be a heat sink block 接 attached to a central processing unit (cpu), and the second heat generating device 22 can be plurally juxtaposed. Memory unit (RAM). However, the electronic device 2, the first heat generating device 2, and the second heat generating device 22 are not limited to the above, but may be changed, and the changes are those that can be considered and appreciated by those skilled in the art. The application, for example, the sub-device 2 can be the blade of the material handler (4), the first heating device 1 can be a hard disk module, and the second heating device 22 can be a working wafer body. The thermal shock device 21 (the heat sink block-heating device 23 can also be connected to the middle. The central processing unit (CPU, the same one, the Τ-备2 can be - and has a pure body, that is, the electronic device The windshield 3 can be re-established: one/handling the 1U < severing device, so the first phase of the guiding channel 34 is again n for the air inlet 31 and the first airway is turned on. , and the airflow contained in the air inlet 3i and the second (fourth) second heat device 23 can also be used to dissipate between the two '35, so that the cooling fan 20 can be heated. When the heat generating device 23 is operated, please refer to the 2β 24, and the first hairline 2 has a top cover, and the clothing 21 is passed through the guide. The opening 3〇1 and the upper cover 19545 10 200810667=the second passage 36, so that the air inlet 2 formed by the cooling fan 2 is inserted into the first passage 34, and is divided into the first heating device. The airflow A1 of 21 and the airflow A2 of the second heat generating device 22 are guided to the channel 36, and the heat dissipation block of the memory unit is blocked by the heat dissipation block of the memory unit in the prior art. However, there is a disadvantage that the heat dissipation performance is poor, and the air guiding cover 3 of the present invention has the air guiding opening σ 3Q1 so that the air flow A2 can be guided by the second passage 36 to the second heat generating device 22 to quickly dissipate the heat energy generated therefrom. The cover plate 30 covers the first heat generating device 21 and covers the second heat generating device, and the air guiding opening 3〇1 covers at least the first material device 2, preferably the air guiding opening 3〇1 may extend to the upper portion of the second heat generating device 22 to facilitate guiding the airflow A2 to the second heat generating device μ. Further, the airtight rubber strip 3〇2 disposed on the cover plate 30 is in close contact with the The upper cover 24 of the electronic device 2 causes the airflow VIII to be concentratedly guided to the second heat generating device 22' The airflow A2 is prevented from being dissipated into the electronic device 2, and the heat dissipation effect of the heat generating device 22 is affected. In addition, referring to FIG. 2C, it can be seen that the electronic device 2 can have a first heat generating device 21 disposed therein. The third heat generating device 23 next to the heat is also cooled by the 5th heat fan 20, but the second heat generating device 22 is not behind the first heat generating device, so the airflow A generated by the cooling fan 2 must have a larger proportion. Guided to the first heat generating device 21, a deflector that can guide most of the heat-dissipating airflow A to the first heat-generating device 21 is disposed adjacent to the air inlet 31 below the i-plate 30. 3〇3, and when the third heating device 23 is not added to the electronic & device 2, the cover plate 304 can be connected under the cover plate 19545 11 200810667, and the concealer plate 3〇4 is used to cover % So that the airflow A is concentrated to the first heat generating device; the traveling direction of the tuyere and the heat dissipating airflow A may be a concealing plate 304
往兮笛一㈣…1 具有將散熱氣流A 彺該弟一發熱裝置21方向導引 並未完全將該第二出風口 35庐#仕 推該遮擋板3〇4 部份的氣流A由該第二出風口 35流動至位於該第= 口 35外之工作晶片（圖未示）。 出風 請參閱第3圖，係本發明之另一較佳具體實施例示音 圖，本實施例與前述實施例敍致相同，而不同之^ 於本實施例之蓋板3〇設有連通於該$ —出風㈣之通 缺口 37:通風缺口 37係至少涵蓋該第二發熱裝置以之 中央區域以減少該中央區域之風阻，俾使集中於該中央區 域之熱能可迅速地散逸而出，_般而言，該第__出風^ 32係接近電子設備2後方之通風開口，因此亦可藉由外 部之冷空氣流人該通風缺口 37而進—步地散逸該第二發 熱裝置22中央區域之熱能。相較於習知技術記憶體單元 之中央區域容易積熱的現象，本發明之導風罩3因具有通 風缺口 37而可將第二發熱裝置22 (記憶體單元）中央區 域之熱能迅速散逸。 ' 由上可知，本發明之導風罩可改善習知缺點，因此具 有高度產業利用價值。 a 上述之實施例僅為例示性說明本發明之原理及其功 效，而非用於限制本發明。任何熟習此技藝之人士均可在 不違背本發明之精神及範疇下，對上述實施例進行修飾與 19545 12 200810667 k化。因此，本發明之權利保護範圍，應如後述之 利範圍所列。 ^ 【圖式簡單說明】 第1圖係顯示一伺服器中關於散熱風扇以及各主 發熱裝置之示意圖； 第2Α圖至第2C圖係顯示本發明之導風罩之一 體實施例；以及 乂彳土具 例 第 圖係顯示本發明之導風罩之另一較佳具體實 施 主要元件符號說明】 1 伺服器 10 散熱塊體 11 記憶體單元 12 政熱風扇 2 電子設備 20 散熱風扇 21 第一發熱裝置 22 第二發熱裝置 23 第三發熱裝置 24 上蓋 3 導風罩 30 蓋板 301 通風開口 302 氣密膠條 19545 13 200810667 • 303 導流板 ’ 304 遮擋板 31 入風口 32 第一出風口 33 侧板 34 第一通道 35 第二出風口 36 第二通道 • 37 通風缺口 A 氣流 A1 氣流 A2 氣流To the whistle one (four)...1 has the heat-dissipating airflow A 彺the younger heat-generating device 21 direction guide does not completely push the second air outlet 35庐# officially pushes the airflow A of the shielding plate 3〇4 The two air outlets 35 flow to a working wafer (not shown) located outside the first port 35. FIG. 3 is a schematic diagram of another preferred embodiment of the present invention. The present embodiment is the same as the foregoing embodiment, and the cover plate 3 of the present embodiment is provided with communication. The $-outlet (four) pass gap 37: the ventilation gap 37 covers at least the central region of the second heat generating device to reduce the wind resistance of the central region, so that the heat concentrated in the central region can be quickly dissipated. In general, the first air outlet 32 is close to the ventilation opening behind the electronic device 2, so that the second heat generating device 22 can be further dissipated by the external cold air flowing through the ventilation gap 37. Thermal energy in the central area. The air hood 3 of the present invention can quickly dissipate the thermal energy in the central region of the second heat generating device 22 (memory unit) by having the venting gap 37 as compared with the phenomenon that heat is easily accumulated in the central portion of the conventional memory unit. As can be seen from the above, the air hood of the present invention can improve the conventional disadvantages and thus has a high industrial utilization value. The above embodiments are merely illustrative of the principles of the invention and its advantages, and are not intended to limit the invention. Any of the above-described embodiments can be modified and modified by those skilled in the art without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be as set forth below. ^ [Simple Description of the Drawings] Fig. 1 is a schematic view showing a heat dissipating fan and main heat generating devices in a server; and Figs. 2 to 2C are views showing an embodiment of the air guiding hood of the present invention; FIG. 1 is a schematic diagram showing another preferred embodiment of the air hood of the present invention. 1 Servo 10 heat sink block 11 memory unit 12 politic heat fan 2 electronic device 20 heat sink fan 21 first heat Device 22 second heat generating device 23 third heat generating device 24 upper cover 3 air guiding cover 30 cover plate 301 ventilation opening 302 airtight rubber strip 19545 13 200810667 • 303 deflector '304 shielding plate 31 air inlet 32 first air outlet 33 side Plate 34 First passage 35 Second air outlet 36 Second passage • 37 Ventilation notch A Air flow A1 Air flow A2 Air flow