以下，對各圖式中所示之相同或同等的構成要件、構件標註相同的符號，並適當省略重複說明。又，為了容易理解，適當放大縮小表示各圖式中的構件的尺寸。又，在各圖式中，省略表示在說明實施形態方面並非重要之構件的一部分。
圖1表示實施形態之薄膜成形裝置1的概略結構。薄膜成形裝置1是將管狀的薄膜進行成形。薄膜成形裝置1具備：模具10、膜厚調節部2、一對的穩定板4、一對的夾送輥5、厚度測量感測器6、及控制裝置7。
模具10將由擠出機(未圖示)供給之熔融樹脂成形為管狀。尤其，模具10藉由從環狀的狹縫18(圖2中後述)擠出熔融樹脂來將熔融樹脂成形為管狀。
膜厚調節部2，將從模具10擠出的熔融樹脂進行膜厚的調節並冷卻。熔融樹脂被冷卻而成形為薄膜。
一對的穩定板4配置於膜厚調節部2的上方，且向一對的夾送輥5之間引導所成形之薄膜。夾送輥5配置於穩定板4的上方，將被引導之薄膜往上拉並將其扁平地折疊。藉由捲繞機(未圖示)捲繞折疊後的薄膜。
厚度測量感測器6配置於膜厚調節部2與穩定板4之間。厚度測量感測器6以既定週期一邊繞管狀的薄膜旋轉一邊測量周向上各位置的膜厚。厚度測量感測器6所產生之測量值被發送至控制裝置7。
控制裝置7向膜厚調節部2發送與從厚度測量感測器6接收之測定結果相應之控制指令。膜厚調節部2接收該控制指令，以膜厚不均變小之方式，調節狹縫18(尤其其吐出口)的寬度。
圖2係表示模具10及膜厚調節部2之剖視圖。圖3係表示模具10及膜厚調節部2之俯視圖。在圖3中，省略表示冷卻裝置3、支撐構件58及閉塞構件66。
模具10包括模具本體11、內周構件12及外周構件14。內周構件12係載置於模具本體11的上表面之大致圓柱狀的構件。外周構件14係環狀的構件，且環繞內周構件12。在內周構件12與外周構件14之間，形成呈環狀且沿上下方向延伸之狹縫18。熔融樹脂朝向上側流經該狹縫18，且熔融樹脂從狹縫18的吐出口(亦即上端開口)18a被擠出，形成與吐出口18a的寬度相應之厚度的薄膜。
在模具本體11的外周安裝有複數個加熱器56。又，在外周構件14的下部(具體而言為後述大徑部27)的外周與外周構件14的上部(具體而言為後述小徑部25)的外周亦安裝有加熱器56。模具本體11及外周構件14藉由加熱器56加熱成所需的溫度。藉此，能夠將流經模具10的內部之熔融樹脂保持為適當的溫度及熔融狀態。
膜厚調節部2包括：冷卻裝置3、複數個(在此為32個)調節單元16、支撐構件58、閉塞構件66、及複數個(與調節單元16相同個數，在此為32個)散熱構件68。
冷卻裝置3配置於模具10的上方。冷卻裝置3具備空氣冷卻環8及環狀的整流構件9。空氣冷卻環8係內周部向下方凹陷之環狀的殼體。在空氣冷卻環8的內周部形成有在上側開口之環狀的吹出口8a。尤其，吹出口8a形成為與環狀的狹縫18同心。
在空氣冷卻環8的外周部，在周向等間隔地形成有複數個軟管口8b。複數個軟管口8b分別連接有軟管(未圖示)，冷卻風經由該軟管從鼓風機(未圖示)送入空氣冷卻環8內。送入空氣冷卻環8內之冷卻風從吹出口8a吹出而吹送至熔融樹脂。
整流構件9以包圍著吹出口8a之方式配置於空氣冷卻環8內。整流構件9對送入空氣冷卻環8內之冷卻風進行整流。藉此，冷卻風在周向以均勻的流量、風速從吹出口8a吹出。
複數個調節單元16以圍繞外周構件14的上端側之方式在周向上例如等間隔地配置。尤其，調節單元16以懸臂狀安裝於外周構件14。複數個調節單元16分別構成為能夠對外周構件14賦予朝向徑向內側的按壓荷重或朝向徑向外側的拉伸荷重。因此，藉由調節複數個調節單元16，能夠在周向上局部調節吐出口18a的寬度，且能夠在周向上局部控制膜厚。膜厚在周向上產生不均時，例如，從與壁厚薄的部分對應(例如位於壁厚薄的部分的下方)之調節單元16對外周構件14賦予拉伸荷重，加大壁厚薄的部分的下方的吐出口18a的間隙。藉此，膜厚不均變小。
支撐構件58為環狀的構件，以環繞著外周構件14的上部之方式載置並固定於複數個調節單元16。在支撐構件58的上方固定著冷卻裝置3。亦即，支撐構件58支撐冷卻裝置3。
閉塞構件66為在中央形成有孔之薄型的圓板狀構件，並設置於空氣冷卻環8的內周部與複數個調節單元16之間。閉塞構件66的詳細的功能構造，隨後結合圖9做說明。
複數個散熱構件68以圍繞外周構件14(具體而言為後述撓性唇部22)之方式配置，作為用於在周向上使撓性唇部22的溫度更加均勻化之機構發揮功能。散熱構件68的詳細的功能構造，隨後結合圖11做說明。
圖4、圖5係表示外周構件14的上部與安裝於其之調節單元16之立體圖及側視圖。在圖4、圖5中，僅表示1個調節單元16，且省略表示剩餘的調節單元16。圖6、圖7係表示調節單元16之立體圖。在圖7中，示出將一對的支撐構件30的一方拆卸後的狀態。
外周構件14的上部具有：小徑部25，形成於上端；中徑部26，在小徑部25的下方形成比小徑部25更大之直徑；及大徑部27，在中徑部26的下方形成比中徑部26更大之直徑。小徑部25具有撓性唇部22。撓性唇部22係指比沿著周向設置之凹狀的缺口部20更靠上側的小徑部25的部分。撓性唇部22以缺口部20為邊界而彈性變形。撓性唇部22包括圓筒狀的本體部28、以及從本體部28向徑向外側突出之環狀的突出環繞部29。
調節單元16包括：一對的支撐構件30，安裝於外周構件14；轉動軸32，固定於一對的支撐構件30；槓桿34，以轉動軸32為支點可轉動地被支撐；動作桿36，接受槓桿34所致之旋轉力而沿軸線方向動作；連結構件38，沿軸線方向連結動作桿36與撓性唇部22；軸承構件40，將動作桿沿軸線方向可滑動地支撐；及致動器24，對槓桿34賦予旋轉力。
一對的支撐構件30形成為平板狀，且彼此平行地利用螺絲固定於外周構件14。在一對的支撐構件30之間設置有用以使槓桿34介入之空間。軸承構件40形成為長方體狀，且在支撐構件30的徑向內側利用螺絲固定於外周構件14。在軸承構件40形成有貫穿徑向之插穿孔42。插穿孔42的內周面構成所謂滑動軸承(無油軸承)，將動作桿36可滑動地支撐。
轉動軸32以其軸朝向水平方向且與徑向大致正交的方式固定於一對的支撐構件30。
動作桿36形成為具有段差之圓柱狀，且其中間部插穿於軸承構件40的插穿孔42。在動作桿36的軸向外側設置有縮徑部44。如後所述，縮徑部44可發揮與槓桿34的連結部之功能。在動作桿36的軸向內側設置有凹狀的卡合部46。如後所述，卡合部46作為與連結構件38的連接部而發揮功能。撓性唇部22的突出環繞部29的外周面(以下，稱為“受壓面23”)與動作桿36的前端面相對向。
從縱剖視觀察時連結構件38形成為分叉形狀。具體而言，在連結構件38，在軸向與外周構件14相對向之面上設置有向下側突出之卡合部48、50。卡合部48與動作桿36的卡合部46呈大致互補形狀。又，在撓性唇部22的突出環繞部29形成有朝軸向下方凹陷之環狀的卡合槽52。卡合部50與該卡合槽52呈大致互補形狀。
以卡合部48卡合在卡合部46且卡合部50卡合在卡合槽52之方式將動作桿36與連結構件38利用螺絲固定。將卡合部48和卡合部46的彼此的對向面設為錐面。藉此，隨著緊固螺絲54，使動作桿36的前端面被撓性唇部22的受壓面23緊壓，使動作桿36與撓性唇部22牢牢固定在一起。藉由連結構件38的卡合部50與動作桿36的前端部夾住撓性唇部22的一部分。藉此，使動作桿36在其軸線方向與撓性唇部22連接。
槓桿34具有沿徑向延伸之長條板狀的本體60，其一端部藉由轉動軸32可轉動地支撐。槓桿34設置成，在非動作的狀態下，使本體60和動作桿36大致平行。又，以從本體60的一端部朝與該本體60的軸線垂直的方向延伸的方式設置有分叉形狀的連結部62。亦即，連結部62由一對的連結片64構成，且構成為使連結片64的間隔比動作桿36的縮徑部44的外徑稍大，連結片64的寬度比縮徑部44的長度稍小。藉由此種構成，以連結部62嵌合在縮徑部44之態樣使槓桿34與動作桿36連結。
另外，只要構成為使槓桿34的旋轉力直接賦予動作桿36即可，並不限定於本實施形態。例如，連結部62亦可以構成為不從本體60的軸線朝垂直方向延伸。本體60的軸線與連結部62的延伸方向亦可以形成銳角，或者形成鈍角。又，槓桿34亦可以設為，在非動作的狀態下，使本體60不與動作桿36平行。
致動器24在本實施形態中係氣動驅動式，且包括：藉由壓縮空氣的供排而動作之兩組的波紋管70、72和波紋管71、73、第1基座75、配置於第1基座75的軸向下側之第2基座76、及4根連結棒77。第1基座75與第2基座76係在軸向上分開配置，且藉由4根連結棒77連結。在槓桿34與第1基座75之間配置有波紋管70、72，且在槓桿34與第2基座之間配置有波紋管71、73。亦即，槓桿34的成為施力點之端部，以夾在波紋管70、72和波紋管71、73之間之方式被支撐。藉由對波紋管70、72或波紋管71、73的一方供給壓縮空氣，將槓桿34朝圖中順時針或逆時針方向旋轉驅動。
在圖5中，若藉由壓縮空氣的供給對波紋管70、72賦予壓力而使波紋管70、72伸長，則槓桿34朝圖中逆時針方向轉動，其旋轉力轉換為朝向動作桿36的軸線方向左側(亦即徑向外側)的力。其結果，對撓性唇部22賦予拉伸荷重，使對應之(亦即該調節單元16的徑向內側的)狹縫18的吐出口18a的部分的間隙朝增大之方向變化。另一方面，若藉由壓縮空氣的供給對波紋管71、73賦予壓力而使波紋管71、73伸長，則槓桿34朝圖中順時針方向轉動，其旋轉力轉換為朝向動作桿36的軸線方向右側(亦即徑向內側)的力。其結果，對撓性唇部22賦予按壓荷重，使對應之狹縫18的部分的間隙朝縮小之方向變化。
為了實現此種氣動驅動，壓縮空氣從未圖示的壓力調整裝置經由形成於第1基座75之供給路75a、形成於第2基座76之供給路76a而供給。壓力調整裝置依據來自調節動作控制部83(後述)的控制指令，控制波紋管70～73內的壓力。
圖8係用以說明調節單元16的動作之說明圖。圖8(A)表示調節單元16的中立狀態(波紋管70～73均為非動作的狀態)，圖8(B)表示調節單元16的擴開動作狀態(僅波紋管70、72動作之狀態)。
藉由調節單元16，使槓桿34的旋轉力在作用點P上可直接賦予動作桿36。亦即，槓桿34的旋轉力作為動作桿36的軸線方向的力而賦予撓性唇部22。此時，動作桿36藉由外周構件14穩定地支撐，因此該軸線方向的力可效率良好地傳遞至撓性唇部22。其結果，能夠使用以調整內周構件12與外周構件14之間的間隙之驅動力有效率地發揮作用。
本實施形態中，如圖8(A)所示構成為，使連結槓桿34與動作桿36的連接點(槓桿34的作用點P)和轉動軸32(槓桿34的支點)之直線L1與動作桿36的軸線L2正交。藉此，使以轉動軸32為中心且通過作用點P之假想圓C的切線方向與動作桿36的軸線方向一致。
因此，如圖8(B)所示，槓桿34的旋轉力的作用點P的方向與動作桿36的軸線方向一致。其結果，槓桿34的旋轉力就那樣成為動作桿36的軸線方向的驅動力，能夠盡量提高力的傳遞效率。亦即，能夠讓使撓性唇部22進行擴開動作時的致動器24的驅動力極有效率地發揮作用(參照圖中粗線箭頭)。
雖省略圖示，在調節單元16的縮窄動作狀態(僅波紋管71、73動作之狀態)下，只是與圖8(B)中的力的方向相反，槓桿34的旋轉力的作用點P的方向與動作桿36的軸線方向仍會一致。其結果，與擴開動作時同樣地，槓桿34的旋轉力直接成為動作桿36的軸線方向的驅動力，且能夠盡量提高力的傳遞效率。亦即，藉由調節單元16，能夠使用以調整狹縫18的吐出口18a的間隔之驅動力有效率地發揮作用。
另外，只要構成為使槓桿34的旋轉力直接賦予動作桿36即可，並不限定於本實施形態。例如亦可構成為，使連結部62的延伸方向(連結轉動軸32與作用點P之方向)與動作桿36的軸線方向形成銳角或鈍角之結果，使槓桿34的旋轉力的作用點P上的方向(為方便起見，亦稱為“旋轉力作用方向”)與動作桿36的軸線方向(為方便起見，亦稱為“軸線力作用方向”)不一致。此時，可以為本體60與動作桿36平行，本體60的軸線與連結部62的延伸方向形成銳角或鈍角者。或者可以為本體60的軸線與連結部62的延伸方向形成直角，本體60與動作桿36非平行者。或者可以為本體60的軸線與連結部62的延伸方向形成銳角或鈍角，且本體60與動作桿36非平行者。此外，作為本體60，亦可採用在至少一部分具有彎折部或彎曲部者(不一定能夠界定軸線之結構)。
圖9係表示調節單元16及周邊之剖視圖。首先，考慮假設不存在閉塞構件66之情況。此時，從空氣冷卻環8的吹出口8a朝上吹出冷卻風，藉此使吹出口8a的下方的空間90，亦即被空氣冷卻環8、熔融樹脂及複數個調節單元16包圍之空間90成為負壓。藉此，通過外周構件14的撓性唇部22的本體部28與空氣冷卻環8的內周部之間的環狀的間隙84，使空氣從空氣冷卻環8的下方流入空間90，並吹送至熔融樹脂。具體而言，空氣從調節單元16的下方或/及外周側通過調節單元16之間的複數個(在此為32個)間隙而流入空氣冷卻環8與複數個調節單元16之間的空間88，且從該空間88使空氣流入空間90。調節單元16之間的間隙在周向上不連續，因此流入空間88之空氣的風量在周向上不均，因此空氣從空間88流入空間90之風量亦在周向上不均。若在周向上風量不均勻之風吹送至熔融樹脂，則熔融樹脂固化之時點在周向上變得不均勻，膜厚在周向上變得不均勻。
相對於此，在本實施形態中，在空氣冷卻環8的內周部與調節單元16之間設置有閉塞構件66。閉塞構件66構成為堵住間隙84。換言之，閉塞構件66構成為，將從外周構件14及複數個調節單元16與空氣冷卻環8之間通過空氣冷卻環8的內周側朝向空氣冷卻環8的上方之流路堵住。
具體而言，在撓性唇部22的本體部28的上端外緣形成有向下側凹陷之環狀的凹部94。閉塞構件66形成為，其內徑比凹部94的底面94a的內徑(本體部28的上表面28a的外徑)大且比底面94a的外徑小。閉塞構件66設置成，其下表面66a的內周側端部與凹部94的底面94a抵接(載置)，且下表面66a的外周側端部與支撐構件58抵接(載置)。
藉由閉塞構件66來限制空氣流入空間90。另外，雖然閉塞構件66與撓性唇部22抵接，但並未固定於撓性唇部22，因此撓性唇部22能夠受到來自調節單元16的荷重而發生彈性變形。亦即，閉塞構件66不阻礙撓性唇部22的彈性變形。
圖10係示意表示控制裝置7的功能及結構之方塊圖。在此所示之各方塊在硬體上能夠由以電腦的CPU為代表之元件或機械裝置來實現，在軟體上能夠由電腦程式等來實現，在此，描述藉由整合該等來實現之功能方塊。因此，本領域技術人員應理解，這些功能方塊能夠藉由硬體、軟體的組合而以各種形式實現。
控制裝置7包括：保持部80、獲取部81、決定部82及調節動作控制部83。獲取部81獲取依據厚度測量感測器6之測量值。保持部80將膜厚與應由調節單元16對外周構件14施加的荷重建立對應關聯來儲存，該荷重是在藉由厚度測量感測器6測量膜厚時，用於使之後成形之薄膜成為目標膜厚。
決定部82決定為了縮小膜厚不均而應由各調節單元16對外周構件14賦予之荷重。尤其，決定部82參照厚度測量感測器6所產生之測量值和保持部80，而決定應對外周構件14賦予之荷重。又，決定部算出要將調節單元16的波紋管70～73的壓力控制為多少，以對外周構件14賦予所決定之荷重。調節動作控制部83向壓力調整裝置發送控制指令，以使波紋管70～73的壓力成為藉由決定部82算出之壓力。
對如上構成之薄膜成形裝置1的動作進行說明。從模具10的吐出口18a擠出熔融樹脂，冷卻裝置3向熔融樹脂吹送冷卻風。藉此，使薄膜成形。此時，厚度測量感測器6以既定週期測量周向上各位置的膜厚。控制裝置7依據厚度測量感測器6所產生之測量值，以膜厚不均變小之方式控制膜厚調節部2的各調節單元16。
以上為薄膜成形裝置1的基本結構及其動作。接著，對用以使撓性唇部22的溫度均勻之均勻化機構進行說明。圖11為圖3的A-A剖視圖。在圖11中，省略表示閉塞構件66。參照圖3和圖11。
在調節單元16中，各構成零件由金屬材料構成，亦即由導熱率比較高的材料構成，且各構成零件不像模具10那樣被加熱器56加熱。因此，調節單元16作為對於模具10，尤其對於其撓性唇部22的散熱構件發揮功能。
由於調節單元16大小的關係，無法以連結構件38在周向上無間隙地配置之方式配置調節單元16。因此，在撓性唇部22的突出環繞部29上，作為散熱構件發揮功能之複數個調節單元16是以在周向上隔著間隔的方式連接。
在此，考慮假設沒有散熱構件68的情況。此時，在突出環繞部29上，散熱構件(調節單元16)是以在周向上隔著間隔的方式連接，因此突出環繞部29的溫度在周向變得不均勻。具體而言，在突出環繞部29中，在連接有作為散熱構件發揮功能之調節單元16的部分(以下，稱為“連接部分”)與未連接有作為散熱構件發揮功能之調節單元16的部分(以下，稱為“非連接部分”)產生溫度差。這樣一來，在撓性唇部22的本體部28，亦在與突出環繞部29的連接部分對應之(亦即連接部分的徑向內側的)部分和與突出環繞部29的非連接部分對應之部分產生溫度差，其結果，關於由本體部28從熔融樹脂帶走之熱，亦在與突出環繞部29的連接部分對應之部分和與突出環繞部29的非連接部分對應之部分產生溫度差。亦即，從模具10擠出的熔融樹脂的溫度在周向變得不均勻。若熔融樹脂的溫度在周向上不均勻，則熔融樹脂固化之時點在周向上變得不均勻，膜厚在周向上變得不均勻。
相對於此，在本實施形態中，是在突出環繞部29的非連接部分連接散熱構件68。亦即，在突出環繞部29上，調節單元16的連結構件38和散熱構件68是在周向上幾乎無間隙地交替連接。藉此，在突出環繞部29上，無論是連接部還是非連接部均與散熱構件連接，因此與沒有散熱構件68的情況相比，突出環繞部29乃至撓性唇部22的溫度在周向上變得更均勻。
本實施形態的散熱構件68包括第1構件78和第2構件79。第1構件78為實質上與調節單元16的連結構件38相同(亦即，形狀、尺寸及材料在設計上相同)的構件。第2構件79為與動作桿36的前端側、亦即與安裝有連結構件38的一側的部分相當之構件。具體而言，第2構件79只要包括供調節單元16的動作桿36的凹狀卡合部46中之連結構件38的卡合部48卡合(接觸)的部分即可。
調節單元16除突出環繞部29以外，亦與中徑部26及大徑部27連接(接觸)，藉由該等支撐。相對於此，散熱構件68僅與突出環繞部29連接(接觸)，僅藉由突出環繞部29支撐。
依據以上說明的本實施形態之薄膜成形裝置1，在撓性唇部22的突出環繞部29上，調節單元16的連結構件38和散熱構件68是在周向上幾乎無間隙地交替連接。亦即，在突出環繞部29上，某個散熱構件是在周向幾乎無間隙地連接。藉此，與沒有散熱構件68的情況相比，突出環繞部29的溫度在周向上變得更均勻，其結果，從模具10擠出的熔融樹脂的溫度亦在周向上變得更均勻，膜厚在周向上變得更均勻。
又，依據本實施形態之薄膜成形裝置1，散熱構件68僅與突出環繞部29連接，因此與亦和中徑部26或大徑部27連接的情況相比，更能使突出環繞部29散熱。因此，與散熱構件68亦和中徑部26或大徑部27連接的情況相比，能夠使散熱構件68從突出環繞部29帶走的熱的量接近調節單元16從突出環繞部29帶走的熱的量。其結果，從模具10擠出的熔融樹脂的溫度在周向上變得更均勻，膜厚在周向上變得更均勻。
又，依據本實施形態之薄膜成形裝置1，散熱構件68的構成零件之一的第1構件78與調節單元16的構成零件之一的連結構件38相同，因此能夠降低散熱構件68乃至薄膜成形裝置1的製造成本。
以上，對實施形態之薄膜成形裝置的結構與動作進行了說明。這些實施形態為例示，本領域技術人員應理解，該等各構成要件的組合能夠有各種變形例，並且這些變形例亦屬於本發明的範圍。
(變形例1)
圖12係表示變形例之散熱構件68及其周邊之剖視圖。圖12與圖11對應。在本變形例中，散熱構件68延伸至相鄰的2個調節單元16的軸承構件40的上方，並載置於該等。具體而言，第2構件79延伸至軸承構件40的上方，例如如圖12所示，第2構件79彎曲並且延伸至軸承構件40的上方，並載置於軸承構件40。另外，散熱構件僅載置於軸承構件40而不固定在軸承構件40，可避免阻礙撓性唇部22的彈性變形。
依據本變形例，散熱構件68在突出環繞部29和相鄰的2個調節單元16的軸承構件40這2處被支撐，因此與散熱構件68僅藉由突出環繞部29支撐的情況相比，散熱構件68被穩定地保持。
(變形例2)
圖13(A)、圖13(B)分別係表示另一變形例之散熱構件68及其周邊之剖視圖。圖13(A)、圖13(B)分別對應圖11。散熱構件68具有：向下側突出而與卡合槽52卡合之卡合部96、在比突出環繞部29更靠徑向外側沿上下方向延伸而與中徑部26的上表面抵接的延伸部97、及連接卡合部96與延伸部97之連接部98。例如散熱構件68，是以在卡合部96與延伸部97之間夾入突出環繞部29之方式壓入突出環繞部29，藉此固定在突出環繞部29。
在圖13(A)的例中，延伸部97具有：上側部分97a、位於比上側部分97a更靠下側之下側部分97b、及連接上側部分97a與下側部分97b之彈性鉸鏈部97c。下側部分97b與模具10的外周構件14的中徑部26的上表面抵接。
彈性鉸鏈部97c構成為能夠伴隨撓性唇部22的彈性變形而進行彈性變形。具體而言，例如彈性鉸鏈部97c形成為至少徑向的厚度比上側部分97a或下側部分97b的厚度薄。藉此，即使散熱構件68的延伸部97的下端與中徑部26的上表面抵接，撓性唇部22的彈性變形仍不會受到阻礙。
在圖13(B)的例中，延伸部97的下端部形成為在縱剖視觀察時為圓形形狀。延伸部97的下端部亦可以形成為半球狀。若撓性唇部22彈性變形，則散熱構件68傾斜移動。此時，散熱構件68的延伸部97的下端部在中徑部26的上表面滾動。反言之，延伸部97的下端部為了能夠與中徑部26的上表面滾動接觸而使該下端部形成為在剖視觀察時為圓形形狀，藉此能夠使散熱構件68傾斜移動。因此，即使散熱構件68的延伸部97的下端與中徑部26的上表面抵接，撓性唇部22的彈性變形仍不會受到阻礙。
依據該等變形例，散熱構件68在突出環繞部29和中徑部26這2處被支撐，因此與散熱構件68僅藉由突出環繞部29支撐的情況相比，散熱構件68被穩定地保持。
(變形例3)
在實施形態及上述變形例中雖未特別提及，但為了使突出環繞部29乃至撓性唇部22的溫度更加均勻，散熱構件68與作為散熱構件發揮功能之調節單元16的散熱性能(亦即熱阻)越接近越佳。
因此，只要以散熱構件68的熱阻接近調節單元16的熱阻之方式，較佳為相同之方式決定散熱構件68的材質、大小、形狀(更增加表面積之形狀)即可。
例如藉由將散熱構件68由熱阻比調節單元16小的材質構成，能夠利用比調節單元16小的散熱構件68實現實質上與調節單元16相同的熱阻，或與由與調節單元16相同材料構成散熱構件68的情況相比，能夠使熱阻更接近調節單元16的熱阻。
另外，散熱構件68上未施加荷重，因此不考慮散熱構件68的強度就能夠決定其材質、大小、形狀。
(變形例4)
薄膜成形裝置1，可以代替散熱構件68或除散熱構件68以外，還具備作為均勻化機構的隔熱材。隔熱材，為了避免調節單元16與撓性唇部22接觸，只要設置於調節單元16的動作桿36及連結構件38與撓性唇部22之間即可。依據本變形例，撓性唇部22的熱不會傳遞到調節單元16，因此抑制起因於調節單元16在周向上隔著間隔與突出環繞部29連接而產生之突出環繞部29在周向上的溫度差，其結果，膜厚在周向上變得更均勻。
(變形例5)
在實施形態所說明的情況，是藉由調節單元16使狹縫18的吐出口18a在徑向的間隙變寬或變窄，藉此使膜厚在周向上局部發生變化，但並不限於此。也可以藉由使從冷卻裝置3吹出的冷卻風的風量及風溫中至少一方在周向上局部發生變化而使膜厚在周向上局部發生變化。此時，冷卻裝置3可以在空氣冷卻環8內具備：用以調節風量之複數個閥、複數個加熱器。
上述實施形態及變形例的任意的組合亦作為本發明的實施形態而有用。藉由組合而產生之新的實施形態，兼具所組合之各實施形態及變形例的效果。又，本領域技術人員亦能夠理解，在申請專利範圍中記載之各構成要件應實現之功能藉由實施形態及變形例中示出之各構成要件的單體或者它們的關聯來實現。In the following, the same or equivalent constituent elements and members shown in the respective drawings are denoted by the same symbols, and duplicate descriptions are omitted as appropriate. In addition, for easy understanding, the size of the members in each drawing is appropriately enlarged or reduced. In addition, in each drawing, a part of components that are not important in explaining the embodiment is omitted.
FIG. 1 shows a schematic structure of a film forming apparatus 1 of an embodiment. The film forming apparatus 1 forms a tube-shaped film. The film forming apparatus 1 includes a mold 10, a film thickness adjustment section 2, a pair of stabilizer plates 4, a pair of pinch rollers 5, a thickness measurement sensor 6, and a control device 7.
The die 10 shapes the molten resin supplied from an extruder (not shown) into a tube shape. In particular, the mold 10 shapes the molten resin into a tube shape by extruding the molten resin from the annular slit 18 (described later in FIG. 2 ).
The film thickness adjustment section 2 adjusts and cools the film thickness of the molten resin extruded from the die 10. The molten resin is cooled and formed into a film.
The pair of stabilizing plates 4 is arranged above the film thickness adjusting portion 2 and guides the formed film between the pair of pinch rollers 5. The pinch roller 5 is arranged above the stabilizing plate 4, and pulls the guided film upward and folds it flatly. The folded film is wound by a winding machine (not shown).
The thickness measurement sensor 6 is arranged between the film thickness adjusting section 2 and the stabilizing plate 4. The thickness measurement sensor 6 measures the film thickness at various positions in the circumferential direction while rotating around the tubular film at a predetermined period. The measurement value generated by the thickness measurement sensor 6 is sent to the control device 7.
The control device 7 sends a control command corresponding to the measurement result received from the thickness measurement sensor 6 to the film thickness adjustment unit 2. The film thickness adjustment unit 2 receives the control command, and adjusts the width of the slit 18 (especially the discharge port) so that the film thickness unevenness becomes smaller.
FIG. 2 is a cross-sectional view showing the mold 10 and the film thickness adjusting portion 2. FIG. 3 is a plan view showing the mold 10 and the film thickness adjusting section 2. In FIG. 3, the cooling device 3, the support member 58 and the blocking member 66 are omitted.
The mold 10 includes a mold body 11, an inner peripheral member 12 and an outer peripheral member 14. The inner peripheral member 12 is a substantially cylindrical member placed on the upper surface of the mold body 11. The outer peripheral member 14 is a ring-shaped member and surrounds the inner peripheral member 12. Between the inner peripheral member 12 and the outer peripheral member 14, a slit 18 formed in a ring shape and extending in the vertical direction is formed. The molten resin flows through the slit 18 toward the upper side, and the molten resin is extruded from the discharge port (that is, the upper end opening) 18a of the slit 18 to form a film having a thickness corresponding to the width of the discharge port 18a.
A plurality of heaters 56 are attached to the outer periphery of the mold body 11. In addition, a heater 56 is also attached to the outer periphery of the lower portion of the outer peripheral member 14 (specifically, the large-diameter portion 27 described later) and the outer periphery of the upper portion of the outer peripheral member 14 (specifically, the small-diameter portion 25 described later). The mold body 11 and the peripheral member 14 are heated to a desired temperature by a heater 56. With this, the molten resin flowing through the inside of the mold 10 can be maintained at an appropriate temperature and molten state.
The film thickness adjustment unit 2 includes: a cooling device 3, a plurality of (in this case, 32) adjustment units 16, a support member 58, a blocking member 66, and a plurality of (the same number as the adjustment unit 16, in this case 32) Radiating member 68.
The cooling device 3 is arranged above the mold 10. The cooling device 3 includes an air cooling ring 8 and an annular rectifying member 9. The air cooling ring 8 is a ring-shaped housing whose inner peripheral portion is recessed downward. In the inner peripheral portion of the air cooling ring 8, a ring-shaped air outlet 8 a that opens on the upper side is formed. In particular, the air outlet 8a is formed concentrically with the annular slit 18.
At the outer peripheral portion of the air cooling ring 8, a plurality of hose ports 8b are formed at equal intervals in the circumferential direction. A plurality of hose ports 8b are respectively connected with hoses (not shown), and cooling air is sent from the blower (not shown) into the air cooling ring 8 via the hoses. The cooling air sent into the air cooling ring 8 is blown out from the air outlet 8a and blown to the molten resin.
The rectifying member 9 is arranged in the air cooling ring 8 so as to surround the air outlet 8a. The rectifying member 9 rectifies the cooling air sent into the air cooling ring 8. With this, the cooling air is blown out from the outlet 8a at a uniform flow rate and wind speed in the circumferential direction.
The plurality of adjusting units 16 are arranged at equal intervals in the circumferential direction so as to surround the upper end side of the outer peripheral member 14, for example. In particular, the adjustment unit 16 is attached to the outer peripheral member 14 in a cantilever shape. The plurality of adjustment units 16 are each configured to be able to apply a pressing load toward the radially inner side or a tensile load toward the radially outer side to the outer peripheral member 14. Therefore, by adjusting the plurality of adjustment units 16, the width of the discharge port 18a can be adjusted locally in the circumferential direction, and the film thickness can be controlled locally in the circumferential direction. When the film thickness is uneven in the circumferential direction, for example, the adjustment unit 16 corresponding to the thin-walled portion (for example, located below the thin-walled portion) applies a tensile load to the outer peripheral member 14 to increase the thickness of the thin-walled portion below Gap of the discharge port 18a. As a result, the film thickness unevenness becomes smaller.
The support member 58 is a ring-shaped member, and is placed and fixed to the plurality of adjustment units 16 so as to surround the upper portion of the outer peripheral member 14. The cooling device 3 is fixed above the support member 58. That is, the support member 58 supports the cooling device 3.
The blocking member 66 is a thin disc-shaped member with a hole formed in the center, and is provided between the inner peripheral portion of the air cooling ring 8 and the plurality of adjustment units 16. The detailed functional structure of the blocking member 66 will be described later with reference to FIG. 9.
The plurality of heat dissipation members 68 are arranged to surround the outer peripheral member 14 (specifically, the flexible lip 22 described later), and function as a mechanism for making the temperature of the flexible lip 22 more uniform in the circumferential direction. The detailed functional structure of the heat dissipation member 68 will be described later with reference to FIG. 11.
4 and 5 are a perspective view and a side view showing the upper part of the outer peripheral member 14 and the adjustment unit 16 attached thereto. In FIGS. 4 and 5, only one adjustment unit 16 is shown, and the remaining adjustment units 16 are omitted. 6 and 7 are perspective views of the adjustment unit 16. FIG. 7 shows a state in which one of the pair of support members 30 is removed.
The upper portion of the outer peripheral member 14 has: a small diameter portion 25 formed at the upper end; a middle diameter portion 26 formed below the small diameter portion 25 to have a larger diameter than the small diameter portion 25; and a large diameter portion 27 at the middle diameter portion 26 The diameter below the is larger than the diameter portion 26. The small-diameter portion 25 has a flexible lip 22. The flexible lip portion 22 refers to a portion of the small-diameter portion 25 above the concave notch portion 20 provided along the circumferential direction. The flexible lip 22 is elastically deformed with the notch 20 as a boundary. The flexible lip 22 includes a cylindrical body portion 28 and an annular protruding surrounding portion 29 that protrudes radially outward from the body portion 28.
The adjusting unit 16 includes: a pair of support members 30 mounted on the outer peripheral member 14; a rotation shaft 32 fixed to the pair of support members 30; a lever 34 supported rotatably with the rotation shaft 32 as a fulcrum; an action lever 36, Accepts the rotational force caused by the lever 34 and moves in the axial direction; the connecting member 38 connects the operating rod 36 and the flexible lip 22 in the axial direction; the bearing member 40 slidably supports the operating rod in the axial direction; and actuates The device 24 imparts rotational force to the lever 34.
The pair of support members 30 are formed in a flat plate shape, and are fixed to the outer peripheral member 14 with screws in parallel to each other. A space is provided between the pair of support members 30 to allow the lever 34 to intervene. The bearing member 40 is formed in a rectangular parallelepiped shape, and is fixed to the outer peripheral member 14 with screws on the radially inner side of the support member 30. The bearing member 40 has an insertion hole 42 penetrating in the radial direction. The inner peripheral surface of the insertion hole 42 constitutes a so-called sliding bearing (oilless bearing), and slidably supports the operating rod 36.
The rotating shaft 32 is fixed to a pair of support members 30 so that its axis faces the horizontal direction and is substantially orthogonal to the radial direction.
The operating rod 36 is formed in a cylindrical shape with a step difference, and the middle portion thereof is inserted through the insertion hole 42 of the bearing member 40. A radially reduced portion 44 is provided on the axially outer side of the operating lever 36. As will be described later, the reduced diameter portion 44 can function as a connection portion with the lever 34. A concave engaging portion 46 is provided on the axially inner side of the operating lever 36. As described later, the engagement portion 46 functions as a connection portion with the connection member 38. The outer peripheral surface (hereinafter referred to as “pressure receiving surface 23 ”) of the protruding surrounding portion 29 of the flexible lip 22 faces the front end surface of the operating lever 36.
The coupling member 38 is formed into a bifurcated shape when viewed from a longitudinal section. Specifically, the coupling member 38 is provided with engaging portions 48 and 50 protruding downward on the surface facing the outer peripheral member 14 in the axial direction. The engaging portion 48 and the engaging portion 46 of the operating lever 36 have a substantially complementary shape. In addition, an annular engagement groove 52 recessed downward in the axial direction is formed in the protruding surrounding portion 29 of the flexible lip 22. The engaging portion 50 and the engaging groove 52 have a substantially complementary shape.
The operating rod 36 and the coupling member 38 are fixed with screws so that the engaging portion 48 is engaged with the engaging portion 46 and the engaging portion 50 is engaged with the engaging groove 52. The facing surfaces of the engaging portion 48 and the engaging portion 46 are tapered surfaces. Thereby, as the screw 54 is tightened, the front end surface of the operating rod 36 is pressed against the pressure receiving surface 23 of the flexible lip 22, so that the operating rod 36 and the flexible lip 22 are firmly fixed together. A part of the flexible lip 22 is sandwiched between the engaging portion 50 of the connecting member 38 and the front end portion of the operating lever 36. As a result, the operating lever 36 is connected to the flexible lip 22 in the axial direction.
The lever 34 has a long plate-shaped body 60 extending in the radial direction, and one end portion thereof is rotatably supported by a rotating shaft 32. The lever 34 is provided so that the main body 60 and the operating rod 36 are substantially parallel in the non-operating state. In addition, a bifurcated coupling portion 62 is provided so as to extend from one end of the body 60 in a direction perpendicular to the axis of the body 60. That is, the connecting portion 62 is composed of a pair of connecting pieces 64, and the interval between the connecting pieces 64 is slightly larger than the outer diameter of the reduced diameter portion 44 of the operating rod 36, and the width of the connecting piece 64 is smaller than that of the reduced diameter portion 44. The length is slightly smaller. With such a configuration, the lever 34 is connected to the operating lever 36 with the connecting portion 62 being fitted in the reduced-diameter portion 44.
In addition, as long as the rotation force of the lever 34 is directly applied to the operating lever 36, it is not limited to this embodiment. For example, the coupling portion 62 may not be configured to extend vertically from the axis of the body 60. The axis of the body 60 and the extending direction of the connecting portion 62 may form an acute angle or an obtuse angle. In addition, the lever 34 may be set so that the main body 60 is not parallel to the operating lever 36 in the non-operating state.
The actuator 24 is pneumatically driven in this embodiment, and includes two sets of bellows 70, 72 and bellows 71, 73, and a first base 75, which are operated by the supply and discharge of compressed air. The second base 76 on the lower side in the axial direction of the first base 75 and the four connecting rods 77. The first base 75 and the second base 76 are arranged separately in the axial direction, and are connected by four connecting rods 77. Bellows 70 and 72 are arranged between the lever 34 and the first base 75, and bellows 71 and 73 are arranged between the lever 34 and the second base. That is, the end of the lever 34 that becomes the point of application is supported so as to be sandwiched between the bellows 70 and 72 and the bellows 71 and 73. By supplying compressed air to one of the bellows 70 and 72 or the bellows 71 and 73, the lever 34 is driven to rotate clockwise or counterclockwise in the figure.
In FIG. 5, if the bellows 70, 72 are extended by applying pressure to the bellows 70, 72 by the supply of compressed air, the lever 34 rotates counterclockwise in the figure, and its rotational force is converted to The force on the left side of the axis (that is, radially outside). As a result, a tensile load is applied to the flexible lip 22, and the gap of the portion corresponding to the discharge port 18a of the slit 18 (that is, radially inward of the adjustment unit 16) changes in the direction of increase. On the other hand, if the bellows 71, 73 are extended by applying pressure to the bellows 71, 73 by the supply of compressed air, the lever 34 rotates clockwise in the figure, and its rotational force is converted to the axis of the operating lever 36 The force on the right side (that is, radially inward). As a result, a pressing load is applied to the flexible lip portion 22, and the gap of the portion corresponding to the slit 18 changes in the direction of reduction.
In order to realize such pneumatic driving, compressed air is supplied from a pressure adjusting device (not shown) via a supply path 75a formed in the first base 75 and a supply path 76a formed in the second base 76. The pressure adjustment device controls the pressure in the bellows 70 to 73 in accordance with a control command from the adjustment operation control unit 83 (described later).
FIG. 8 is an explanatory diagram for explaining the operation of the adjustment unit 16. 8(A) shows the neutral state of the adjustment unit 16 (the bellows 70 to 73 are all in a non-operating state), and FIG. 8(B) shows the expanded operation state of the adjustment unit 16 (only the bellows 70 and 72 operate ).
By the adjustment unit 16, the rotational force of the lever 34 can be directly given to the action lever 36 at the point of action P. That is, the rotational force of the lever 34 is given to the flexible lip 22 as a force in the axial direction of the operating lever 36. At this time, the operating lever 36 is stably supported by the outer peripheral member 14, so the force in the axial direction can be efficiently transmitted to the flexible lip 22. As a result, the driving force for adjusting the gap between the inner peripheral member 12 and the outer peripheral member 14 can be effectively used.
In this embodiment, as shown in FIG. 8(A), it is configured such that the straight line L1 connecting the connecting point of the lever 34 and the operating lever 36 (the operating point P of the lever 34) and the rotating shaft 32 (the fulcrum of the lever 34) and the operation The axis L2 of the rod 36 is orthogonal. As a result, the tangent direction of the virtual circle C passing through the action point P with the rotation shaft 32 as the center coincides with the axial direction of the operating lever 36.
Therefore, as shown in FIG. 8(B), the direction of the action point P of the rotational force of the lever 34 coincides with the axial direction of the operating lever 36. As a result, the rotational force of the lever 34 becomes the driving force in the axial direction of the operating lever 36 as it is, and the transmission efficiency of the force can be improved as much as possible. That is, the driving force of the actuator 24 when the flexible lip 22 is expanded can be made to function extremely efficiently (refer to the thick-line arrows in the figure).
Although omitted from the illustration, in the narrowing operation state of the adjustment unit 16 (the state where only the bellows 71 and 73 are operated), only the direction of the force in FIG. 8(B) is opposite, and the point of action P of the rotational force of the lever 34 is The direction of and the axis direction of the action lever 36 will still be consistent. As a result, as in the expansion operation, the rotational force of the lever 34 directly becomes the driving force in the axial direction of the operation lever 36, and the transmission efficiency of the force can be improved as much as possible. That is, the adjustment unit 16 can efficiently use the driving force for adjusting the interval between the discharge ports 18a of the slit 18.
In addition, as long as the rotation force of the lever 34 is directly applied to the operating lever 36, it is not limited to this embodiment. For example, it may be configured such that the extending direction of the connecting portion 62 (the direction connecting the rotating shaft 32 and the action point P) and the axis direction of the operating lever 36 form an acute angle or an obtuse angle, so that the rotational force of the lever 34 acts on the action point P The direction (for convenience, also referred to as "rotational force acting direction") and the axis direction of the actuating lever 36 (for convenience, also referred to as "axial force acting direction") are inconsistent. In this case, the body 60 may be parallel to the operating lever 36, and the axis of the body 60 may form an acute angle or an obtuse angle with the extending direction of the connecting portion 62. Alternatively, the axis of the body 60 and the extending direction of the connecting portion 62 may form a right angle, and the body 60 and the operating lever 36 are not parallel. Or, the axis of the body 60 and the extending direction of the connecting portion 62 may form an acute angle or an obtuse angle, and the body 60 and the operating rod 36 are not parallel. In addition, as the body 60, it is also possible to adopt a structure having a bent portion or a bent portion in at least a part (a structure that does not necessarily define an axis).
9 is a cross-sectional view showing the adjustment unit 16 and its surroundings. First, consider the case where there is no blocking member 66. At this time, the cooling air is blown upward from the air outlet 8a of the air cooling ring 8, thereby making the space 90 below the air outlet 8a, that is, the space 90 surrounded by the air cooling ring 8, the molten resin, and the plurality of adjustment units 16 Become negative pressure. By this, the annular gap 84 between the body portion 28 of the flexible lip 22 of the outer peripheral member 14 and the inner peripheral portion of the air cooling ring 8 allows air to flow into the space 90 from below the air cooling ring 8 and be blown To molten resin. Specifically, air flows into the space 88 between the air cooling ring 8 and the plurality of adjustment units 16 through the plurality of (here, 32) gaps between the adjustment units 16 from below or/and the outer peripheral side of the adjustment units 16 , And air flows into the space 90 from the space 88. The gap between the adjusting units 16 is discontinuous in the circumferential direction, so the air volume of the air flowing into the space 88 is uneven in the circumferential direction, so the air volume of the air flowing from the space 88 into the space 90 is also uneven in the circumferential direction. When the wind with uneven air volume in the circumferential direction is blown onto the molten resin, the molten resin becomes uneven in the circumferential direction at the time of solidification, and the film thickness becomes uneven in the circumferential direction.
On the other hand, in this embodiment, a blocking member 66 is provided between the inner peripheral portion of the air cooling ring 8 and the adjustment unit 16. The blocking member 66 is configured to close the gap 84. In other words, the blocking member 66 is configured to block the flow path from the outer peripheral member 14 and the plurality of adjustment units 16 and the air cooling ring 8 through the inner peripheral side of the air cooling ring 8 toward the upper side of the air cooling ring 8.
Specifically, an annular recess 94 recessed downward is formed on the outer edge of the upper end of the main body 28 of the flexible lip 22. The blocking member 66 is formed so that its inner diameter is larger than the inner diameter of the bottom surface 94a of the recess 94 (the outer diameter of the upper surface 28a of the body portion 28) and smaller than the outer diameter of the bottom surface 94a. The blocking member 66 is provided such that the inner peripheral end of the lower surface 66a abuts (places) the bottom surface 94a of the recess 94, and the outer peripheral end of the lower surface 66a abuts (places) the support member 58.
The blocking member 66 restricts the inflow of air into the space 90. In addition, although the blocking member 66 is in contact with the flexible lip 22, it is not fixed to the flexible lip 22, and therefore the flexible lip 22 can be elastically deformed by the load from the adjustment unit 16. That is, the blocking member 66 does not hinder the elastic deformation of the flexible lip 22.
FIG. 10 is a block diagram schematically showing the function and structure of the control device 7. The various blocks shown here can be implemented in hardware by components or mechanical devices represented by the computer's CPU, and in software by computer programs, etc. Here, the description is implemented by integrating these Function block. Therefore, those skilled in the art should understand that these functional blocks can be implemented in various forms by a combination of hardware and software.
The control device 7 includes a holding unit 80, an acquisition unit 81, a determination unit 82, and an adjustment operation control unit 83. The acquisition section 81 acquires the measurement value based on the thickness measurement sensor 6. The holding portion 80 stores the film thickness in association with the load that should be applied to the outer peripheral member 14 by the adjustment unit 16, and the load is used to make the film to be formed later when the film thickness is measured by the thickness measurement sensor 6. Target film thickness.
The determination unit 82 determines the load to be applied to the outer peripheral member 14 by each adjustment unit 16 in order to reduce the unevenness of the film thickness. In particular, the determination section 82 refers to the measurement value generated by the thickness measurement sensor 6 and the holding section 80 to determine the load to be applied to the outer peripheral member 14. In addition, the determination unit calculates how much the pressure of the bellows 70 to 73 of the adjustment unit 16 is to be controlled to apply the determined load to the outer peripheral member 14. The adjustment operation control unit 83 sends a control command to the pressure adjustment device so that the pressure of the bellows 70 to 73 becomes the pressure calculated by the determination unit 82.
The operation of the film forming apparatus 1 configured as above will be described. The molten resin is extruded from the discharge port 18a of the die 10, and the cooling device 3 blows cooling air to the molten resin. By this, the film is formed. At this time, the thickness measurement sensor 6 measures the film thickness at each position in the circumferential direction at a predetermined cycle. The control device 7 controls each adjustment unit 16 of the film thickness adjustment unit 2 in such a manner that the film thickness unevenness becomes smaller based on the measurement value generated by the thickness measurement sensor 6.
The above is the basic structure and operation of the film forming apparatus 1. Next, a homogenizing mechanism for making the temperature of the flexible lip 22 uniform will be described. Fig. 11 is a cross-sectional view taken along line A-A of Fig. 3. In FIG. 11, the blocking member 66 is omitted. Refer to Figures 3 and 11.
In the adjustment unit 16, each component is composed of a metal material, that is, a material having a relatively high thermal conductivity, and each component is not heated by the heater 56 like the mold 10. Therefore, the adjustment unit 16 functions as a heat dissipation member for the mold 10, particularly for the flexible lip 22 thereof.
Due to the size of the adjustment unit 16, the adjustment unit 16 cannot be arranged so that the coupling member 38 is arranged without a gap in the circumferential direction. Therefore, on the protruding surrounding portion 29 of the flexible lip 22, a plurality of adjusting units 16 functioning as a heat dissipating member are connected at intervals in the circumferential direction.
Here, it is assumed that there is no heat radiation member 68. At this time, on the protruding surrounding portion 29, the heat dissipating members (adjusting unit 16) are connected at intervals in the circumferential direction, so the temperature of the protruding surrounding portion 29 becomes uneven in the circumferential direction. Specifically, in the protruding surrounding portion 29, a portion where the adjustment unit 16 functioning as a heat dissipation member is connected (hereinafter, referred to as a "connection portion") and a portion where the adjustment unit 16 functioning as a heat dissipation member is not connected (Hereinafter, referred to as "non-connected portion") A temperature difference occurs. In this way, the body portion 28 of the flexible lip 22 also corresponds to the connecting portion of the protruding surrounding portion 29 (that is, radially inward of the connecting portion) and corresponds to the non-connecting portion of the protruding surrounding portion 29 As a result, there is a temperature difference at the part, and as a result, the heat taken away from the molten resin by the body part 28 also generates a temperature at the part corresponding to the connecting part of the protruding surrounding part 29 and the part corresponding to the non-connecting part of the protruding surrounding part 29 difference. That is, the temperature of the molten resin extruded from the die 10 becomes uneven in the circumferential direction. If the temperature of the molten resin is uneven in the circumferential direction, the molten resin becomes uneven in the circumferential direction at the time of solidification, and the film thickness becomes uneven in the circumferential direction.
In contrast, in the present embodiment, the heat dissipation member 68 is connected to the non-connecting portion of the protruding surrounding portion 29. That is, on the protruding surrounding portion 29, the coupling member 38 and the heat radiating member 68 of the adjustment unit 16 are alternately connected with almost no gap in the circumferential direction. Thereby, both the connecting portion and the non-connecting portion are connected to the heat dissipating member on the protruding surrounding portion 29, so the temperature of the protruding surrounding portion 29 and even the flexible lip 22 is circumferentially higher than that without the heat dissipating member 68 Becomes more uniform.
The heat dissipation member 68 of this embodiment includes a first member 78 and a second member 79. The first member 78 is substantially the same as the connecting member 38 of the adjustment unit 16 (that is, the shape, size, and material are the same in design). The second member 79 is a member corresponding to the front end side of the operating lever 36, that is, the portion on the side where the coupling member 38 is attached. Specifically, the second member 79 only needs to include a portion where the engaging portion 48 of the coupling member 38 in the concave engaging portion 46 of the operating lever 36 of the adjustment unit 16 is engaged (contacted).
In addition to the protruding surrounding portion 29, the adjusting unit 16 is also connected (contacted) with the middle diameter portion 26 and the large diameter portion 27 by these supports. In contrast to this, the heat dissipation member 68 is only connected (in contact) with the protruding surrounding portion 29 and is supported only by the protruding surrounding portion 29.
According to the film forming apparatus 1 of the present embodiment described above, the connecting member 38 and the heat dissipating member 68 of the adjustment unit 16 are alternately connected with almost no gap in the circumferential direction on the protruding surrounding portion 29 of the flexible lip 22. That is, on the protruding surrounding portion 29, a certain heat radiating member is connected with almost no gap in the circumferential direction. By this, the temperature of the protruding surrounding portion 29 becomes more uniform in the circumferential direction compared to the case without the heat dissipation member 68, and as a result, the temperature of the molten resin extruded from the mold 10 also becomes more uniform in the circumferential direction, and the film The thickness becomes more uniform in the circumferential direction.
In addition, according to the film forming apparatus 1 of the present embodiment, the heat dissipation member 68 is only connected to the protruding surrounding portion 29, so that the protruding surrounding portion 29 can be dissipated more than when the middle diameter portion 26 or the large diameter portion 27 is also connected. . Therefore, compared with the case where the heat dissipating member 68 is also connected to the middle diameter portion 26 or the large diameter portion 27, the amount of heat taken away from the protruding surrounding portion 29 by the heat dissipating member 68 can be taken away from the protruding surrounding portion 29 by the adjustment unit 16 The amount of heat. As a result, the temperature of the molten resin extruded from the die 10 becomes more uniform in the circumferential direction, and the film thickness becomes more uniform in the circumferential direction.
In addition, according to the film forming apparatus 1 of the present embodiment, the first member 78 which is one of the constituent parts of the heat dissipation member 68 is the same as the connecting member 38 which is one of the constituent parts of the adjustment unit 16, so that the heat dissipation member 68 and even the film forming apparatus can be reduced 1 Manufacturing cost.
The structure and operation of the film forming apparatus of the embodiment have been described above. These embodiments are examples, and those skilled in the art should understand that various combinations of these constituent elements can have various modifications, and these modifications also fall within the scope of the present invention.
(Modification 1)
12 is a cross-sectional view showing a heat dissipation member 68 and its surroundings in a modified example. Fig. 12 corresponds to Fig. 11. In this modification, the heat dissipation member 68 extends above the bearing members 40 of the two adjacent adjustment units 16 and is placed on the same. Specifically, the second member 79 extends above the bearing member 40. For example, as shown in FIG. 12, the second member 79 bends and extends above the bearing member 40, and is placed on the bearing member 40. In addition, the heat dissipation member is placed only on the bearing member 40 and is not fixed to the bearing member 40, so that the elastic deformation of the flexible lip portion 22 can be prevented.
According to this modification, the heat dissipation member 68 is supported at two places of the protruding surrounding portion 29 and the bearing members 40 of the two adjacent adjustment units 16, so compared with the case where the heat dissipating member 68 is supported only by the protruding surrounding portion 29, The heat dissipation member 68 is stably held.
(Modification 2)
13(A) and 13(B) are cross-sectional views showing a heat dissipation member 68 and its surroundings according to another modification. 13(A) and 13(B) correspond to FIG. 11 respectively. The heat dissipation member 68 has an engaging portion 96 that protrudes downward and engages with the engaging groove 52, and extends radially outward of the protruding surrounding portion 29 in the vertical direction and abuts the upper surface of the middle diameter portion 26 The extending portion 97 and the connecting portion 98 connecting the engaging portion 96 and the extending portion 97. For example, the heat dissipating member 68 is pressed into the protruding surrounding portion 29 so as to sandwich the protruding surrounding portion 29 between the engaging portion 96 and the extending portion 97, thereby being fixed to the protruding surrounding portion 29.
In the example of FIG. 13(A), the extending portion 97 includes an upper portion 97a, a lower portion 97b located lower than the upper portion 97a, and an elastic hinge portion 97c connecting the upper portion 97a and the lower portion 97b. The lower portion 97b is in contact with the upper surface of the middle diameter portion 26 of the outer peripheral member 14 of the mold 10.
The elastic hinge portion 97c is configured to be elastically deformable along with the elastic deformation of the flexible lip 22. Specifically, for example, the elastic hinge portion 97c is formed so that the thickness in at least the radial direction is thinner than the thickness of the upper portion 97a or the lower portion 97b. Thereby, even if the lower end of the extending portion 97 of the heat dissipating member 68 abuts the upper surface of the middle diameter portion 26, the elastic deformation of the flexible lip portion 22 will not be hindered.
In the example of FIG. 13(B), the lower end portion of the extension portion 97 is formed into a circular shape when viewed in a longitudinal section. The lower end of the extension 97 may be formed in a hemispherical shape. When the flexible lip 22 is elastically deformed, the heat dissipation member 68 moves obliquely. At this time, the lower end portion of the extension portion 97 of the heat dissipation member 68 rolls on the upper surface of the middle diameter portion 26. Conversely, the lower end portion of the extension portion 97 is formed into a circular shape when viewed in cross-section in order to enable rolling contact with the upper surface of the middle diameter portion 26, whereby the heat dissipating member 68 can be tilted. Therefore, even if the lower end of the extending portion 97 of the heat dissipating member 68 abuts the upper surface of the middle diameter portion 26, the elastic deformation of the flexible lip portion 22 will not be hindered.
According to these modified examples, the heat dissipating member 68 is supported at two places of the protruding surrounding portion 29 and the middle diameter portion 26, so the heat dissipating member 68 is stably held compared to the case where the heat dissipating member 68 is supported only by the protruding surrounding portion 29 .
(Modification 3)
Although not specifically mentioned in the embodiment and the above modification, in order to make the temperature of the protruding surrounding portion 29 and even the flexible lip 22 more uniform, the heat dissipation performance of the heat dissipation member 68 and the adjustment unit 16 functioning as a heat dissipation member (also That is, the closer the thermal resistance), the better.
Therefore, as long as the thermal resistance of the heat dissipation member 68 is close to the thermal resistance of the adjustment unit 16, it is preferable to determine the material, size, and shape of the heat dissipation member 68 in the same manner (a shape that increases the surface area).
For example, by making the heat dissipation member 68 made of a material having a smaller thermal resistance than the adjustment unit 16, the heat dissipation member 68 smaller than the adjustment unit 16 can achieve substantially the same thermal resistance as the adjustment unit 16, or the same as the adjustment unit 16 Compared with the case where the heat dissipation member 68 is made of material, the thermal resistance can be made closer to the thermal resistance of the adjustment unit 16.
In addition, since no load is applied to the heat dissipation member 68, its material, size, and shape can be determined regardless of the strength of the heat dissipation member 68.
(Modification 4)
The film forming apparatus 1 may include a heat insulating material as a homogenizing mechanism instead of or in addition to the heat radiating member 68. In order to avoid the contact between the adjustment unit 16 and the flexible lip 22, the heat insulating material may be provided between the actuating lever 36 and the connecting member 38 of the adjustment unit 16 and the flexible lip 22. According to this modification, the heat of the flexible lip 22 is not transferred to the adjustment unit 16, so that the circumferential portion of the protruding surrounding portion 29 caused by the adjustment unit 16 being connected to the protruding surrounding portion 29 at intervals in the circumferential direction is suppressed As a result of the temperature difference, the film thickness becomes more uniform in the circumferential direction.
(Modification 5)
In the case described in the embodiment, the gap of the discharge port 18a of the slit 18 in the radial direction is widened or narrowed by the adjusting unit 16, thereby locally changing the film thickness in the circumferential direction, but it is not limited to this . The film thickness may be locally changed in the circumferential direction by changing at least one of the air volume and the wind temperature of the cooling air blown from the cooling device 3 in the circumferential direction. At this time, the cooling device 3 may be provided in the air cooling ring 8 with a plurality of valves and a plurality of heaters for adjusting the air volume.
Any combination of the above-mentioned embodiments and modified examples is also useful as an embodiment of the present invention. The new embodiment resulting from the combination has the effects of the combined embodiments and modifications. In addition, those skilled in the art can understand that the functions to be realized by each of the constituent elements described in the scope of the patent application are realized by the individual elements of the constituent elements shown in the embodiments and modification examples or their association.
