1303550 九、發明說明： 【發明所屬之技術領域】 寺別疋指一種用於散熱器 本發明是有關於一種扣具 之扣具。 【先前技術】 中央處理器（CPU)等電子元件在運行過程 量的熱，若不及時排除其產生之熱量， ：大 累積，進而引起溫度升高，嚴重 ：：：持續 从· 0电于兀件之正常運作 。為此，業界通常於電子元件之表面緊密地貼 ，以輔助電子元件散熱。為使該 …為 食匕替f “ 熱固定在電路板上而 W地貼合至電子元件表面，目前較為常用的固定方式 I分為兩種’其—為螺合的方式，另—則為塑性扣具扣合 、方式1乂下分別敘述兩種固定方式之缺點。 土參閱圖卜一電子元件11安襄於-電路板12上，且兩 形=電連接，而該電子^件n之表面則設置有—鱗片狀 月二态13，δ亥散熱器13則藉由多數個螺絲μ與螺帽U而 固定，該電路板12上，並且緊密地貼合於該電子元件η表 \母—螺絲14皆穿伸過該散熱器13與電路板12，且其 末而疋大出於该電路板12之背面，並利用所述螺帽Η分 別螺合於每一螺絲14末端上，藉以將該散熱器13與電路 板12固定在一起。 _然而’為了加強該電子元件11之散熱效率，所以通常 ㈢在違散熱器13上另外安裝一散熱風扇5，但是該散熱風 羽5於運轉時’勢必會伴隨一定程度的震動現象，長久使 1303550 用下來’每-螺絲14與螺帽15之間極可能形成鬆動，導 致该散熱器13與電路板12之固定力較為不^，造成該散 熱器13會與電子元件n脫離而沒有呈現緊密貼合的狀態， 使得該電子元件U所產生的熱量不易傳遞至該散熱器13上 ’降低其散熱效率。 參閱圖2,另一種塑性扣具2扣合的方式，則是提供多 數個塑性扣具2(圖中只顯示其—），穿伸過該散熱器13與電 路板12,並且使兩者固定在一起。每一扣纟2包含一頭部 21、一連接該頭部21之柱體22、一設於該柱體22上且呈 倒錐狀之扣爪部23，及一套設於該柱體22外周面的彈簧 24 ’ &扣爪部23與頭部21之直徑皆大於該柱體22之直徑 ，逡扣爪部23於其端面中心處形成有一切槽231，且該切 才曰231疋延伸至该柱體22内部，該電路板與散熱器υ 上都形成有多數個直徑與該柱體22相#大小的穿孔ΐ2ΐ、 13卜 田組虞時，首先使其中—扣具2的扣爪部Μ穿插於該 政熱荔13之穿孔ι31巾，此時該扣爪部23便向該切槽叫 處收敛，然後再穿過該電路板12之穿孔121，並藉由該扣 爪P 23鉤扣在孩電路板12之背面而達到將該散熱器η與 電路板12固定在—起的目的。至於其餘扣具2也是依照上 述方式I亥政熱器13之其餘邊緣處也固定於該電路板Η 上。 4疋此種扣具2通常是利用塑性材料射出一體成型 所製成，耐熱性較為不佳，尤其該扣爪冑23扣合時受力較 6 1303550 大’在該電子元件11附近的高熱環境下很容易產生軟化、 、吏形’或脫卡專現象，以致不易配合使用；再者，由於該 - 散熱器13是由金屬材質製成，容易對該扣爪部23形成磨 損，而磨損至一定程度後，該扣爪部23便不易牢靠地鉤扣 於该電路板12之背面，導致該散熱器13可能會與電子元 件11脫離而沒有緊密貼合，降低該電子元件u的散熱效率 〇 _ 【發明内容】 口此，本叙明之目的，即在提供一能夠有效地將散熱 器與電路板穩固地結合在一起，以使該散熱器與發熱元件 緊密貼合的扣具。 於是，本發明用於散熱器之扣具，用以將該散熱器貼 觸定位於一發熱元件上，該發熱元件則安裝於一電路板上 ，該扣具包含一用以供該散熱器設置之基板，及複數個用 以使該基板固定於該電路板上之扣合單元。 φ 每一扣合單元具有一軸座、一封套件、一螺帽，及一 螺合元件。該軸座穿伸過該基板與電路板，且其兩端分別 突出於兩者之外，該封套件具有一套設於該軸座之一端上 的開放端、一相反於該開放端之末端、一形成於該末=上 的嵌槽，及一連通該嵌槽與開放端的通道，該螺帽是固設 於該封套件之嵌槽内，該螺合元件則穿伸過該軸座、該= 套件之開放端、通道、嵌槽，並且與該螺帽螺合固定。 本發明之功效在於，利用每一扣合單元之螺帽是固設 於該封套件之嵌槽内，並且與該螺合元件螺合固定，所以 1303550 即使該螺合元件轉動，也不會只相對該螺帽轉動，而是會 令該軸座與封套件都隨之轉動’藉此方式，可以避免螺合 元件與螺帽之間產生退牙現象，使該散熱器即不易與該電 路板上之發熱元件形成脫離，能夠有效確保該發熱元件的 散熱效率。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下配合參考圖式之兩個較佳實施例的詳細說明中，將可 清楚的呈現。 在本發明被詳細描述之前，要注意的是，在以下的說 明中，類似的元件是以相同的編號來表示。 參閱圖3、4，本發明用於散熱器31之扣具*的第一較 佳實施例，用以將該散熱器31貼觸定位於一發熱元件32( 例如CPU)上，該發熱元件32則安裝於一電路板33上，該 扣具4包含一用以供該散熱器31設置之基板41，及複數個 用以使該基板41固定於該電路板33上之扣合單元42。 該基板41具有一本體411、一貫通該本體411且用以 供該散熱器31設置之容置部412 ,及多數個供相對應的扣 合單元42設置的扣合部413。每一扣合單元42具有一軸座 43、一封套件44、一螺帽45，及一螺合元件46，該電路板 33上形成有多數個穿孔331。 該軸座43具有一觸抵於該基板41之本體411上且位於 該扣合部413外的基壁431，及一連接該基壁431且穿伸過 該基板41之扣合部413與電路板33之穿孔331的圍壁432 1303550 ’該圍壁432界定出一可供該螺合元件46穿伸過之軸槽 433，並且該圍壁432於遠離該基壁431之一端上係形成有 二相對設置之第一限位部434，及二分別位於該二第一限位 部434之間且連通該軸槽433的第一缺口部435，該圍壁 432之直徑係小於該基壁431之直徑，而每一扣合部413與 穿孔331之直徑則稍大於該圍壁432之直徑，以使得每一 軸座43可以自由地在任一扣合部413與穿孔331之間轉動 〇 該封套件44具有一套設於該軸座43之圍壁432突出 於該電路板33外侧的開放端441、一相反於該開放端441 之末端442、一形成於該末端442上且可供該螺帽45固設 於其中的嵌槽443，及一連通該嵌槽443與開放端441的通 道444，該螺帽45為一六角螺帽，該嵌槽443配合該螺帽 45之外型，也呈現一六角狀，且該嵌槽443相反兩側緣的 間距係大於該通道444之直徑，以使得該螺帽45只會定位 於該嵌槽443内，而不會進入該通道444内。 該開放端441係形成有二相對設置的第二限位部445， 及二分別位於該二第二限位部445之間且連通該通道444 的第二缺口部446。該螺合元件46具有一觸抵定位於該軸 座43之基壁431上的頭部461，及一連接該頭部461且形 成有螺紋的桿身部462。 當組裝該扣具4，以使該散熱器31固定於該電路板33 上時，首先是將其中一扣合單元42之軸座43的圍壁432 依序牙伸過該基板41之扣合部413與電路板33之穿孔331 9 1303550 ，直到該軸座43的基壁431觸抵於該基板4ι之本體4ΐι上 ，此時，便可將該封套件44之開放端441套設於該轴座Μ 之圍壁432突出於該電路板33外側的部分，而其套設方式 即是利用每-第-限位部434與第二缺〇部桃互相搭配 容置定位’每一第二限位部445與第一缺口部奶也是同 樣地互相搭配容置定位，蕤μ古 疋彳精此方式，使得該封套件44能夠 套設於該軸座43突出於該電路板33外側的部分。 而該螺合元件46之桿身部462即可穿伸過該軸座43 之軸槽433、該封套件44之開放端44ι、通道444、嵌槽 443,並且利用形成於其上的螺紋，而與固定於該嵌槽相 内的螺帽45螺合固定。 :由上述之叹片，即可使該扣具4之基板^固定於該 、路板33上’而设置於該基板41之容置部化内的散埶 器31則貼觸於該發熱元件32的表面，並且配合每一扣;； 早几42之螺帽45是固設於該封套件44之㈣443内，且 4=與該螺合元件46螺合固定的設計，就可使該螺合元件 46轉動時，帶動該軸座43與封套件料隨之轉動。 Ρ使在Θ放熱Α 31上再安裝—用以加速散熱效率的散 =羽(圖中未不)’並且因為該散熱風扇運轉時所產生的震 動杜使得該螺合元件46更容易形成轉動的狀況下，該螺合 免碟仍不會相對於該螺帽45轉動，藉此方式’可以避 即不IS牛46與螺帽45之間產生退牙現象’該散熱器31 緊…亥電路板33上之發熱元件32形成脫離，而能夠 地貼合於該發熱元件Μ之表面，以使得該發熱元件32 10 1303550 31上，有效確保 所產生的熱量可以迅速地傳遞至該散熱器 该發熱元件32的散熱效率。 參閱圖5,本發明用於散熱器3 實::v大致類似於該第-較佳實施例，不同= 基板4!與散熱器31是—體成型所製成，並且每一扣 合早兀42更具有一套設於該螺合元件46之桿身部娘上 的弹性件47，且該彈性件47的兩端係分別觸抵於該抽座 43之第一限位部434底緣以及該封套件44之第二缺口部 446底緣，在本實施例中，該彈性件4?是一彈菩。 藉由上述之設計，當其中一扣合單元42之螺合元件私 穿伸過該軸座43、該封套件44之開放端441、通道物、 後槽443，而與該螺帽45互相螺合固定之&，即可藉由該 彈性件47所提供的彈性回復力作為該軸座钧與封套件料 之間的緩衝機制，不僅可以避免該軸座43過於迫緊該封套 件44，造成該封套件44損壞，而且更可以依照實際需求， 調整分配該散熱器31與電路板33兩者之間的迫緊固定力 歸納上述，本發明用於散熱器31之扣具4，不僅可以 使δ亥政熱為31與電路板33兩者穩固地結合在一起，而且 更可以避免螺合元件46與螺帽45之間產生退牙現象，使 得該散熱器31不易與該電路板33上之發熱元件32形成脫 離，而能夠緊密地貼合於該發熱元件32之表面，有效確保 該發熱元件32的散熱效率，所以確實能夠達到本發明之目 的0 11 1303550 惟以上所述者，僅為本發明之較佳實施例而已，當不 能以此限定本發明實施之範圍，即大凡依本發明申請專利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 【圖式簡單說明】 圖1是一侧視剖面圖，說明 是利用螺合方式固定的態樣； 習知一散熱器與一 電路板1303550 IX. Description of the invention: [Technical field to which the invention pertains] Temple 疋 refers to a type of heat sink. The present invention relates to a buckle for a buckle. [Prior Art] The heat of the electronic components such as the central processing unit (CPU) is not excessively excluded from the heat generated during the operation process: large accumulation, which causes the temperature to rise, serious::: Continued from 0. The normal operation of the pieces. For this reason, the industry usually closely attaches to the surface of electronic components to assist in heat dissipation of electronic components. In order to make the food "fake" on the circuit board and heat it to the surface of the electronic component, the currently used fixing method I is divided into two types, which are screwed together, and the other is The plastic fasteners are fastened, and the shortcomings of the two fixing methods are respectively described in the following manner. The soil is referenced to the electronic component 11 and mounted on the circuit board 12, and the two shapes are electrically connected, and the electronic components are The surface is provided with a scaly moon-shaped state 13, and the δ-Hai radiator 13 is fixed by a plurality of screws μ and a nut U, and the circuit board 12 is closely attached to the electronic component η table - the screws 14 are threaded through the heat sink 13 and the circuit board 12, and at the end thereof are widened from the back surface of the circuit board 12, and are respectively screwed onto the ends of each of the screws 14 by the nut bolts. The heat sink 13 and the circuit board 12 are fixed together. However, in order to enhance the heat dissipation efficiency of the electronic component 11, a heat radiating fan 5 is usually additionally mounted on the heat sink 13 but the heat radiating wind 5 is in operation. Time is bound to be accompanied by a certain degree of vibration, long-term use of 1303550 It is highly probable that looseness will occur between the screw 14 and the nut 15 , resulting in a relatively small fixing force between the heat sink 13 and the circuit board 12 , causing the heat sink 13 to be detached from the electronic component n without presenting a close fit. The state is such that the heat generated by the electronic component U is not easily transmitted to the heat sink 13 'reducing the heat dissipation efficiency. Referring to FIG. 2, another manner of fastening the plastic fastener 2 is to provide a plurality of plastic fasteners 2 (only shown in the figure -), extending through the heat sink 13 and the circuit board 12, and fixing the two together. Each buckle 2 includes a head 21 and a cylinder 22 connecting the head 21. a claw portion 23 disposed on the column 22 and having an inverted tapered shape, and a set of springs 24' & the claw portion 23 and the head portion 21 disposed on the outer peripheral surface of the column 22 are larger than the diameter The diameter of the cylinder 22, the claw portion 23 is formed with a groove 231 at the center of the end surface thereof, and the slit 231 疋 extends to the inside of the column 22, and a plurality of the circuit board and the heat sink are formed. When the diameter is the same as that of the cylinder 22, the perforation ΐ 2ΐ, 13 卜田组虞, firstly the buckle of the buckle 2 The Μ ι ι 31 Μ Μ ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι ι The hook is fastened to the back of the circuit board 12 to achieve the purpose of fixing the heat sink η and the circuit board 12. The remaining buckles 2 are also fixed to the remaining edges of the hi-heater 13 according to the above manner. On the circuit board 。 4 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋 疋In the high heat environment nearby, it is easy to produce softening, 吏-shaped or de-carding phenomenon, so that it is difficult to use together; further, since the heat sink 13 is made of a metal material, it is easy to wear the claw portion 23 After being worn to a certain extent, the claw portion 23 is not easily fastened to the back surface of the circuit board 12, so that the heat sink 13 may be detached from the electronic component 11 without being closely attached, and the electronic component is lowered. Heat dissipation efficiency 〇 _ _ content Thus, the purpose of the present description is to provide a clip that effectively bonds the heat sink to the circuit board to closely fit the heat sink to the heat generating component. Therefore, the present invention is applied to a fastener for a heat sink for positioning the heat sink on a heating element, the heating element is mounted on a circuit board, and the buckle includes a heat sink for the heat sink. a substrate, and a plurality of fastening units for fixing the substrate to the circuit board. φ Each fastening unit has a shaft seat, a sleeve, a nut, and a screwing element. The shaft seat extends through the substrate and the circuit board, and the two ends of the sleeve protrude from the two ends. The package has a set of open ends disposed on one end of the shaft seat and an end opposite to the open end. a slot formed in the end=, and a passage connecting the slot and the open end, the nut is fixed in the slot of the package, and the screw component extends through the axle seat, The = open end of the kit, the channel, the slot, and screwed to the nut. The utility model has the advantages that the nut of each fastening unit is fixed in the groove of the sealing sleeve and screwed and fixed with the screwing component, so that the 1303550 does not only rotate even if the screwing component rotates. Rotating relative to the nut, but causing the shaft seat and the sealing sleeve to rotate together, thereby preventing the tooth from being thrown between the screwing element and the nut, so that the heat sink is not easy to be connected with the circuit board. The heat generating element is detached, and the heat dissipation efficiency of the heat generating element can be effectively ensured. The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention. Before the present invention is described in detail, it is noted that in the following description, like elements are denoted by the same reference numerals. Referring to Figures 3 and 4, a first preferred embodiment of the present invention for the fasteners * of the heat sink 31 is used to position the heat sink 31 in a heating element 32 (e.g., a CPU). It is mounted on a circuit board 33. The clip 4 includes a substrate 41 for the heat sink 31, and a plurality of fastening units 42 for fixing the substrate 41 to the circuit board 33. The substrate 41 has a body 411, a receiving portion 412 extending through the body 411 for the heat sink 31, and a plurality of engaging portions 413 for the corresponding fastening units 42. Each of the fastening units 42 has a shaft seat 43, a sleeve 44, a nut 45, and a screwing member 46. The circuit board 33 is formed with a plurality of perforations 331. The shaft base 43 has a base wall 431 which is disposed on the body 411 of the substrate 41 and located outside the fastening portion 413, and a fastening portion 413 and a circuit connecting the base wall 431 and extending through the substrate 41. The surrounding wall 432 1303550 of the perforation 331 of the plate 33 defines a shaft groove 433 through which the screwing member 46 can pass, and the surrounding wall 432 is formed at one end away from the base wall 431. The first limiting portion 434 is disposed opposite to the second limiting portion 434 and the first notch portion 435 is connected to the axial groove 433. The diameter of the surrounding wall 432 is smaller than the base wall 431. The diameter of each of the engaging portions 413 and the through holes 331 is slightly larger than the diameter of the surrounding wall 432, so that each of the shaft seats 43 can be freely rotated between any of the engaging portions 413 and the through holes 331. 44 has a set of open walls 432 disposed on the outer side of the circuit board 33, an open end 441 protruding from the outer side of the circuit board 33, and an end 442 opposite to the open end 441, formed on the end 442 and available for the nut a slot 443 fixed in the slot 443, and a passage 444 connecting the slot 443 and the open end 441, the nut 45 is a The angle nut is matched with the nut 45 and also has a hexagonal shape, and the spacing between the opposite side edges of the slot 443 is greater than the diameter of the channel 444, so that the nut 45 is only It will be positioned within the slot 443 without entering the channel 444. The open end 441 is formed with two oppositely disposed second limiting portions 445, and two second notch portions 446 respectively located between the second and second limiting portions 445 and communicating with the channel 444. The screw member 46 has a head portion 461 that abuts against a base wall 431 of the shaft seat 43, and a shaft portion 462 that connects the head portion 461 and is formed with a thread. When the clip 4 is assembled to fix the heat sink 31 to the circuit board 33, firstly, the surrounding wall 432 of the shaft seat 43 of one of the fastening units 42 is sequentially extended over the substrate 41. The portion 413 and the through hole 331 9 1303550 of the circuit board 33 until the base wall 431 of the shaft base 43 touches the body 4 ΐ ι of the substrate 4 ι, at which time the open end 441 of the sealing sleeve 44 can be placed on the body 413 The surrounding wall 432 of the shaft seat 突出 protrudes from the outer portion of the circuit board 33, and the arranging manner is to use the per-first-limit portion 434 and the second missing portion peach to match each other to position each second. The limiting portion 445 is also positioned and placed in the same manner as the first notched portion of the milk, so that the sealing member 44 can be sleeved on the portion of the shaft seat 43 that protrudes outside the circuit board 33. . The shaft portion 462 of the screw member 46 can extend through the shaft groove 433 of the shaft seat 43, the open end 44 of the seal 44, the passage 444, the groove 443, and utilize the thread formed thereon. The nut 45 fixed in the groove phase is screwed and fixed. The substrate 31 of the clip 4 can be fixed to the road plate 33 by the above-mentioned slap piece, and the diffuser 31 disposed in the accommodating portion of the substrate 41 is in contact with the heat generating element. The surface of 32 is matched with each buckle; the nut 45 of the early 42 is fixed in the (4) 443 of the sealing kit 44, and 4 = the screwing and fixing with the screwing member 46, the screw can be made When the component 46 rotates, the shaft seat 43 and the package material are driven to rotate.再 reinstalling on the Θ heat Α 31—the scatter=feather (not shown) to accelerate the heat dissipation efficiency and the vibration caused by the operation of the cooling fan makes the screw element 46 more likely to form a rotation. In this case, the screw-free disc still does not rotate relative to the nut 45, thereby avoiding the phenomenon of tooth egress between the IS cow 46 and the nut 45. The heat sink 31 is tight... The heating element 32 on the 33 is detached and can be attached to the surface of the heating element , so that the heating element 32 10 1303550 31 effectively ensures that the generated heat can be quickly transferred to the heat sink. 32 heat dissipation efficiency. Referring to FIG. 5, the present invention is applied to the heat sink 3::v is substantially similar to the first preferred embodiment, the difference = the substrate 4! and the heat sink 31 are formed by body molding, and each of the fastenings is early. The elastic member 47 is disposed on the bottom of the first limiting portion 434 of the suction member 43 and The bottom edge of the second notch portion 446 of the package 44. In the embodiment, the elastic member 4 is a bullet. With the above design, when the screwing element of one of the fastening units 42 is privately passed through the shaft seat 43, the open end 441 of the sealing sleeve 44, the passage, and the rear groove 443, the nut 45 is screwed with the nut 45. The fixed restoring force can be used as a buffering mechanism between the shaft seat and the sealing material by the elastic restoring force provided by the elastic member 47, and the shaft seat 43 can be prevented from being too tightly tightened. The package 44 is damaged, and the pressing force between the heat sink 31 and the circuit board 33 can be adjusted according to actual needs. The buckle 4 for the heat sink 31 of the present invention can be The δHui heat 31 is firmly combined with the circuit board 33, and the toothing phenomenon between the screwing member 46 and the nut 45 is further prevented, so that the heat sink 31 is not easily connected to the circuit board 33. The heat generating component 32 is detached, and can be closely attached to the surface of the heat generating component 32, thereby effectively ensuring the heat dissipation efficiency of the heat generating component 32. Therefore, it is possible to achieve the object of the present invention. 0 11 1303550 However, the above is only Better of the present invention Example only, and when this can not limit the scope of embodiments of the present invention, i.e., almost all under this invention and the scope of the invention patent described a simple modifications and equivalent content made not belong are still within the scope of the present invention encompasses the patent. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side cross-sectional view showing a state fixed by a screwing method; a conventional heat sink and a circuit board are known.
圖2是一側視剖面圖，說明另一習知散熱器與電路 是利用塑性扣具扣合固定的態樣； N 板 圖3是一立體分解圖，說明本發明用於散熱器之呈 的第一較佳實施例，其各部構件之相對位置； ϋ具 圖4是一側視剖面圖，說明一散熱器藉 ^ 叫°茨第~勒1 4 貫施例，安裝固定於一電路板上之態樣；2 is a side cross-sectional view showing another conventional heat sink and circuit that is fastened by a plastic fastener; N-plate FIG. 3 is an exploded perspective view showing the present invention for use in a heat sink. The first preferred embodiment, the relative positions of the components; the cooker FIG. 4 is a side cross-sectional view showing a heat sink mounted on a circuit board by means of a solution Aspect
圖5是一側視剖面圖，說明本發明用 的第二較佳實施例’將該散熱器與電路板 樣。 於散熱器 固定在一 之扣具 起之態 12 1303550Fig. 5 is a side elevational cross-sectional view showing the second preferred embodiment for use in the present invention. The heat sink is fixed at a buckle. 12 1303550
【主要元件符號說明】 31 散熱器 434 第一限位部 32 發熱元件 435 第一缺口部 33 電路板 44 封套件 331 穿孔 441 開放端 4 用於散熱器之扣 442 末端 具 443 般槽 41 基板 444 通道 411 本體 445 第二限位部 412 容置部 446 第二缺口部 413 扣合部 45 螺帽 42 扣合單元 46 螺合元件 43 軸座 461 頭部 431 基壁 462 桿身部 432 圍壁 47 彈性件 433 軸槽 13[Main component symbol description] 31 Heat sink 434 First limit portion 32 Heat generating element 435 First notch portion 33 Circuit board 44 Sealing kit 331 Perforation 441 Open end 4 Fastener buckle 442 End with 443 groove 41 Substrate 444 Channel 411 body 445 second limiting portion 412 accommodating portion 446 second notch portion 413 fastening portion 45 nut 42 fastening unit 46 screwing element 43 shaft seat 461 head portion 431 base wall 462 shaft portion 432 surrounding wall 47 Elastic member 433 shaft groove 13