200306908 玖、發爾說明 【發明所屬之技術領域】 本發明係有關一種藉伺服馬達將曲柄軸或偏心輪 (eccentric)軸等偏心軸旋轉驅動，並透過肘節連桿機構驅動 滑件之伺服壓機（servo press)之滑件控制裝置及其控制方法 【先前技術】 近年來，均要求壓機加工製品的高精密化（形狀、尺寸 的精度高）以及用來提高生產性的壓機加工的高速化。就回 應此要求的壓機而言，有人提出一種線性伺服壓機，其藉 伺服馬達將滾珠螺桿朝上下一直線驅動，藉此直接以高精 度控制滑件之位置及速度，而精密地將滑件上下驅動。 【發明內容】 發明所欲解決之持術問顆 不過，在如上述藉滾珠螺桿將滑件沿上下直接驅動之 構造中，施加於滑件上的負載亦施加於滾珠螺桿，故滾珠 螺桿易於磨損，有滾珠螺桿的耐久性對壓機性能影響大的 問題。 因此，強烈希望實現一種具有肘節連桿機構之伺服壓 機，其構造既具有習知機械式連桿型壓機的優點，又具有 伺服馬達驅動所產生之滑件精密控制性。此種伺服壓機， 係例如，可藉伺服馬達將曲柄軸或偏心輪軸等偏心軸旋轉 200306908 驅動，並透過連結於此偏心軸偏心位置之肘節連桿機構而 將滑件上下驅動，例如於圖6及圖7分別顯示側面局部剖 面圖、後面局部剖面圖之伺服壓機。該壓機1，係藉伺服馬 達21將曲柄軸、偏心輪軸等偏心軸28旋轉驅動，並透過 連結於該偏心軸28偏心位置之肘節連桿機構（由連桿13、 12a、12b構成）將滑件3上下驅動。又，當以既定旋轉速度 使該伺服馬達21定速旋轉時，即藉由偏心軸28之偏心長 度、肘節連桿機構之各連桿長度、偏心軸28之旋轉中心位 置與肘節連桿之關係所決定之既定連桿動作，將滑件3驅 動。又，動作表示滑件位置與時間之關係。 圖8顯示此情形之連桿動作的例子，橫軸表示偏心軸 之旋轉角度，縱軸表示滑件位置。如圖8所示，由於偏心 軸轉一圈係對應於滑件的最大行程Smax，亦即自上死點至 下死點之行程，故當單向連續旋轉伺服馬達時，滑件即以 最大行程Smax上下運動。雖然隨模具形狀、加工條件之不 同，有時必要的行程亦可爲短行程，例如圖示之短行程S0 ，不過，於此情形下若仍以最大行程Smax驅動滑件，則不 僅動力浪費，而且因無法增加壓機之加工行程數（每分鐘之 加工循環數）而有無法提高生產性之問題。因此，必須將滑 件控制成其滑件行程小於最大行程Smax。 另一方面，爲了發揮連桿動作型壓機的優點而有一種 加工方法，其利用肘節連桿機構所產生之於下死點之加壓 能力之強度來進行，在此情形，能以下死點爲基準來設定 滑件行程，將滑件以使其通過下死點之方式加以控制。就 200306908 此情形之控制方法而言，能將伺服馬達控制成，其往復於 對應下死點之偏心軸角度（圖8之0 d)與對應必要行程S0之 角度（圖8之β 0)之間。但若使用此種控制方法，由於須在 壓機一循環中將滑件停止於下死點及滑件上限位置U0二處 ，故頻繁進行伺服馬達之加速和減速以及正轉和反轉，因 此，因馬達負荷增加而容易發生過負荷，同時因難以提高 滑件行程數而降低生產性。 又，爲了以高精度將滑件下限位置加以定位，並驅動 滑件，而例如能如圖9所示，將下死點前方之既定位置當 作下限位置Da加以控制，但在此情形亦同樣地須於對應設 定行程Sa之上限位置Ua以及下限位置Da之二處使滑件停 止，故發生上述相同的問題。 本發明著眼於上述問題點所開發者，其目的在於提供 一種能設定任意的滑件行程，並可提高壓機行程數之伺服 壓機之滑件控制裝置及其控制方法。 用以解決問顆之手段、作用及功效 爲了達成上述目的，第1發明爲一種伺服壓機之滑件 控制裝置，其特徵在於，係具有：滑件（3)之驅動用伺服馬 達（21);受該伺服馬達（21)所旋轉驅動之偏心軸（28);設於 偏心軸（28)偏心位置與滑件（3)之間的肘節連桿機構；及控 制器（10)，其當以包含對應於滑件下死點或上死點之該偏心 軸（28)旋轉角度將該偏心軸（28)正反旋轉驅動時，控制伺服 馬達（21)之速度，以正反大致相同之加工動作來控制滑件 200306908 又，第3發明是對應於裝置發明之第1發明之方法發 明，爲一種伺服壓機之滑件控制方法，係藉伺服馬達將偏 心軸旋轉驅動，並透過肘節連桿機構驅動滑件，此方法當 以包含對應於滑件下死點或上死點之偏心軸旋轉角度將該 偏心軸正反旋轉驅動時，控制伺服馬達之速度，以正反大 致相同之加工動作來控制滑件。 根據第1或第3發明，在通過下死點之往復控制模式 時、或通過上死點之往復控制模式時，在以包含對應於下 死點或上死點之偏心軸位置（旋轉角度）朝正轉側及反轉側之 對應於既定行程之上限位置或下限位置之位置間，分別將 偏心軸往復旋轉驅動，藉此，滑件自上限位置，通過下死 點，連續移動至上限位置，或自下限位置，通過上死點， 連續移動至下限位置。因此，在壓機之1循環中，滑件僅 停止於上限位置或下限位置，故反覆進行伺服馬達之加速 、減速、正轉及反轉之次數減低，可防止伺服馬達之過負 荷。又由於可縮短1循環所需的時間，故可提高加工行程 數，增加生產性。 再者，此時，由於以在偏心軸之正轉及反轉時使加工 行程之動作大致相等之方式控制伺服馬達之速度，故可消 除反覆進行正轉及反轉所造成之加工動作之改變，而經常 以穩定的連桿動作驅動滑件。結果，能以高精度維持加工 製品之品質。 第2發明係於第1發明中具備設定動作資料之動作設 定機構，該動作資料至少包含滑件之行程；且該控制器當 200306908 滑件之比滑件最大行程爲小之行程設定完成後算出一種動 作，在對應於滑件下死點或上死點之偏心軸旋轉角度算起 朝正轉側及反轉側之分別對應於該行程之角度間，使偏心 軸正反旋轉。 又，第4發明係於第3發明中，當滑件之比最大行程 爲小之行程設定完成後，在對應於滑件下死點或上死點之 偏心軸旋轉角度算起朝正轉側及反轉側之分別對應於該行 程之角度間，偏心軸正反旋轉。 根據第2或第4發明，由於可配合加工條件、運轉條 件等將行程設定成小於最大行程，而將偏心軸往復驅動於 與所設定之行程相對應之偏心軸旋轉角度之間，故可彈性 對應行程之改變，並藉此可提高生產性。 【實施方式】 以下，參考圖面，說明本發明之實施形態。 圖6及圖7分別係應用本發明之伺服壓機之側面局部 剖面圖及後面局部剖面圖。 於圖6及圖7中，壓機1係伺服壓機，藉伺服馬達21 驅動滑件3。滑件3上下移動自如地支承於壓機1之本體機 架2之大致中央部，在面向滑件L之下部配設有安裝於床 部3上之承梁5。在形成於滑件3上部之孔內，模具閉合高 度調整用螺軸7之本體部以防止鬆脫狀態、可轉動自如之 方式插著。螺軸7之螺紋部7a從滑件3向上露出，與設於 螺軸7上方的柱塞11之下部之陰螺紋部螺合。 200306908 於螺軸7之本體部外周裝設有蝸齒輪8之蝸輪8a，與 此蝸輪8a螺合的蝸齒輪8之蝸桿8b透過齒輪9a連結於安 裝在滑件3後面部之感應馬達9之輸出軸。感應馬達9 ’係 以軸向長度短之扁平形配置成小型化。 前述柱塞11之上部藉銷11轉動自如地與第1連桿12a 之一端部連結，在此第1連桿12a之另一端部、與一端部 轉動自如地連結於本體機架2之第2連桿12b之另一端部 之間，設在三軸連桿13 —側之二個連結孔藉銷14a、14b轉 動自如地連結。三軸連桿13另一側之連結孔轉動自如地連 結於後文詳述之滑件驅動部20之偏心軸28。藉第1連桿 12a、第2連桿12b及三軸連桿13構成肘節連桿機構。 滑件驅動用伺服馬達21以軸心朝向壓機左右方向安裝 於本體機架2之側面部，皮帶23(通常由確動皮帶構成）捲 裝於安裝在該伺服馬達21之輸出軸之第1帶輪22a與安裝 於中間軸24之第2帶輪22b之間，此中間軸24以軸心朝 向壓機左右方向轉動自如地設在伺服馬達21上方。又，驅 動軸27轉動自如地支承於中間軸24上方之本體機架2上 ’安裝於驅動軸27 —端側之齒輪26與安裝於中間軸24之 齒輪25嚙合。並且，於驅動軸27之軸向中間部形成偏心 軸28，前述三軸連桿13之另一側轉動自如地連結於此偏心 軸28之外周部。 又，於滑件3內形成與前述螺軸7之下端面部間密閉 之油室6，此油室6透過形成於滑件3內之油路6a連接於 切換閥16。切換閥16切換操作油對油室6內部之供給、排 11 200306908 放。於衝壓加工時，將油供入油室6內，透過油室6內之 油將加壓時之緊壓力傳遞至滑件30。若過負荷施加於滑件 3，油室6內之油超過既定値，油即自圖略之保險閥回流至 油槽，滑件3緩衝既定量，使滑件3及模具不致於損壞。 又，於滑件3之後面部安裝自上下兩處朝本體機架2 之側面部突出之1對托架31、31，位置檢測器32安裝於上 下1對托架31、31之間。線性標尺（linear scale)等位置感測 器33之本體部上下作動自如地嵌插於設置位置檢測用標尺 部之位置檢測桿32。位置感測器33固定於設在本體框架2 側面部之輔助機架34。此輔助機架34沿上下方向形成縱長 ，下部藉螺栓35安裝於本體機架2側面部，上部藉***圖 略之上下方向長孔內之螺栓36而沿上下方向滑動自如地受 支撐，側部藉前後一對支撐構件37、37被抵接、支撐。 由於輔助機架34作成僅將上下任一側（於本例爲下側） 固定於本體機架2，而將另一側上下作動自如地支撐之構造 ，故不會受到本體機架2因溫度變化而伸縮的影響。藉此 ，前述位置感測器33不會受到本體機架2因溫度變化而伸 縮的影響，可正確檢測滑件位置及模具閉合高度。 圖1係本發明控制裝置之硬體構造方塊圖，茲藉圖1 說明控制構造。 本控制裝置具備控制器10、動作設定機構17、記憶體 10a、位置感測器33、伺服放大器45以及滑件驅動用伺服 馬達21。 動作設定機構17可設定滑件動作，具有用來設定滑件 12 200306908 行程及滑件行程數（SPM)之十進位輸入器（ten-key)等開關、 或來自1C卡等外部儲存媒體（記憶有預先設定完成之滑件 動作資料）之資料輸入裝置。又，亦可由透過無線或通訊線 路發送接收資料之通信裝置來構成。 記憶體10a記憶上述設定完成之滑件動作資料（行程及 行程數等），同時記憶著滑件控制用之馬達旋轉角度與滑件 位置之關係資料。此馬達旋轉角度與滑件位置之關係資料 係藉前述肘節連桿機構之各連桿12a、12b、13之長度、偏 心軸28之偏心長度、及偏心軸28之旋轉中心位置與肘節 連桿之關係等機械尺寸所決定之函數式而求出之資料，可 記憶此函數本身，或者亦可將此函數式作成列表資料加以 記憶。 前述位置感測器33將檢測出之滑件位置輸出至控制器 10 〇 控制器10由電腦裝置或PLC(可程式邏輯控制器，即所 謂的可程式定序器）等高速運算裝置所構成。控制器10參 考記憶於前述記憶體l〇a之馬達旋轉角度與滑件位置之關 係資料，根據前述動作設定機構Π所設定之滑件行程及滑 件行程數之資料，以滑件按照前述所設定之動作來移動之 方式，進行後文詳細說明之運算處理，求出伺服馬達21之 速度指令，輸出至伺服放大器45。 來自圖略之伺服馬達旋轉角度感測器之馬達旋轉角度 被反饋至伺服放大器45。伺服放大器45運算來自控制器 10之速度指令與由此馬達旋轉角度所求得速度反饋信號之 13 200306908 偏差値，根據所求得之偏差値以減小該偏差値之方式控制 伺服馬達21。藉此，以高精度控制滑件之位置及速度。 其次，根據圖2所示控制功能方塊圖，參考圖3至圖5 分別顯示之滑件控制方法之說明圖，說明控制裝置之各控 制功能。其中，圖3槪念地顯示前述偏心軸28之旋轉與滑 件位置之關係，圖4係以包含下死點往復驅動時之動作說 明圖，又，圖5係以包含上死點往復驅動時之動作說明圖 〇 首先，說明本發明控制方法之基本槪念。本發明滑件 控制方法之第1實施例說明以包含對應於滑件下死點之位 置將偏心軸28以正反旋轉之方式往復驅動之情形，第2實 施例說明以包含對應於滑件上死點之位置將偏心軸28以正 反旋轉之方式往復驅動之情形。 如圖3所示，將對應於連桿動作下死點之偏心軸28旋 轉角度稱爲0d(通常大於180度），將對應於上死點之偏心 軸28旋轉角度稱爲0 u(通常小於360度）。第1實施例中， 使偏心軸28於該角度0d算起朝負方向（以下稱反轉方向） 隔既定角度之旋轉角度、與該角度算起朝正方向（ 以下稱正轉方向）隔既定角度02之旋轉角度之間往復驅動 ，藉以將滑件以包含下死點之方式於一上限位置U1、與另 一上限位置U2之間連續往復驅動。在此，對應於朝反轉方 向隔既定角度01之角度的上限位置ΙΠ、與對應於朝正轉 方向隔既定角度02之角度的上限位置U2係相同位置，這 些上限位置Ul、U2與下死點間之距離對應於設定行程S1。 200306908 第2實施例中，將偏心軸28在對應於上死點之偏心軸 28旋轉角度0 u算起朝反轉方向隔既定角度β 3之旋轉角度 、與朝正轉方向隔既定角度Θ 3之旋轉角度之間往復驅動， 藉以將滑件以包含上死點之方式於一下限位置D1、與另一 下限位置D2之間連續往復驅動。在此，對應於朝反轉方向 隔既定角度0 3之角度的下限位置D1、與對應於朝正轉方 向隔既定角度Θ 4之角度的下限位置D2係相同位置，這些 下限位置Dl、D2與上死點間之距離對應於所設定行程S2。 如前述由偏心軸28之偏心長度、肘節連桿機構之各連 桿長度、偏心軸28之旋轉中心位置與肘節連桿之關係所決 定之連桿動作，係如圖3所示，在包含下死點或上死點朝 正轉側與反轉側，旋轉角度0與滑件位置之關係爲非對稱 ，相異。亦即，在下死點起之反轉側，滑件位置相對於以 一定速度改變之旋轉角度0是緩慢改變，相反地，於正轉 側，滑件位置是急遽改變。又，在上死點起之正轉側，滑 件位置是緩慢改變，相反地，於反轉側，滑件位置是急遽 改變。然而，由於在加工行程（抵接於工件之位置附近）之滑 件速度是左右製品品質非常重要之成形條件，故即使在正 反旋轉驅動情形下，須使在加工行程之滑件速度均等。 因此，第1實施例中，在行程S1之上限位置U1或上 限位置U2起向下死點移動之滑件下降行程之至少在加工行 程時，經常以大致等於上述緩慢的連桿動作之方式藉伺服 馬達21控制偏心軸28之旋轉速度，而精密地控制滑件之 位置及速度。 15 200306908 第2實施例中，在上死點起向行程S2之下限位置D1 或下限位置D2移動之滑件下降行程之至少在加工行程時， 以大致等於各個既定之連桿動作之方式藉伺服馬達21控制 偏心軸28，而精密地控制滑件之位置及速度。 爲了達成上述動作，而具有圖2所示之各功能部。 動作設定部43，係根據藉前述動作設定機構17所設定 之滑件驅動模式、滑件行程S1及行程數N(SPM)等動作資料 ，來決定表示控制執行時間t與滑件位置P之關係的動作。 更具體地，當滑件驅動模式爲以第1實施例之型態驅 動滑件之通過下死點之往復控制模式時，要決定自包含下 死點之該一上限位置U1或U2經由下死點至該另一上限位 置U2或U1間之動作。亦即，如圖4左側所示，藉伺服馬 達21將偏心軸28朝正轉方向驅動，將滑件於自上限位置 U1經由下死點至上限位置U2之間往復控制時，決定以一 定速度正轉（或者，至少於上昇行程中當作最大馬達速度）情 形之動作。藉此，滑件，係如上述在上限位置U1至下死點 之間以緩慢的連桿動作下降，而在下死點至上限位置U2之 間以急遽的上昇動作上昇。此時之1循環所需的時間係由 前述所設定之行程數N所決定之時間。又，如圖4右側所 示，在將偏心軸28朝反轉方向驅動，將滑件在自上限位置 U2經由下死點至上限位置U1之間往復控制時，爲了在上 限位置U2至下死點之間使滑件，以與上述正轉方向驅動時 之上限位置U1至下死點同樣地緩慢的連桿動作下降，而決 定大致與此相等之連桿動作。而且，於此亦可僅使至少二 16 200306908 者之加工行程AW之動作相等。並且，於下死點至上限位 置之間，決定以一定速度（通常爲最大速度）朝反轉方向旋轉 驅動之動作。藉此，可使反轉時之加工動作大致與正轉時 相等。 又，在滑件驅動模式爲藉由第2實施例之型態驅動滑 件之通過上死點之往復控制模式時，決定自包含上死點之 前述一下限位置D1或D2起經由上死點至前述另一上限位 置D2或D1間之動作。亦即，在如圖5左側所示，首先藉 伺服馬達21將偏心軸28朝正轉方向驅動，將滑件於上死 點至下限位置D2之間控制時，決定以一定速度正轉情形之 動作。藉此，滑件於上死點至下限位置D2之間是以緩慢的 連桿動作下降。 其次，藉伺服馬達21朝反轉方向驅動偏心軸28，在自 下限位置D2經由上死點至下限位置D1之間控制滑件。此 時，決定以一定速度（通常爲最大速度）於下限位置D2至上 死點之間反轉情形之動作。又，爲了在上死點至下限位置 D1之間控制伺服馬達21之速度，決定大致與上述正轉方 向驅動時之上死點至下限位置D2相同之緩慢連桿動作。而 且，在此亦可僅使至少二者之加工行程AW之動作大致相 同。藉此，滑件以大致與前述上死點至下限位置D2對稱的 動作上昇之後，再以大致相同之動作下降。 其次，在如圖5右側所示，朝正轉方向驅動偏心軸28 ，於自上限位置D1經由上死點至下限位置D2之間往復控 制滑件時，決定於下限位置D1至上死點之間以一定速度( 17 200306908 通常爲最大速度）正轉情形之動作，決定上死點至下限位置 D2之間如前述以一定速度正轉情形之動作。 以下，反覆對上述動作進行往復控制。 馬達/滑件關係資料記憶部44將表示前述伺服馬達21 之旋轉角度與滑件位置之關係之資料記憶於前述記憶體10a 內。且若如同例如圖8所示，以偏心軸28之旋轉角度0 (0 度至360度）與滑件之關係表示此伺服馬達21之旋轉角度與 滑件位置之關係，即易於瞭解滑件之連桿動作。並且由於 此連桿動作之函數式由前述肘節連桿機構之各連桿長度、 偏心軸28之偏心長度、偏心軸28之旋轉中心位置與肘節 連桿機構之關係以及偏心軸28之旋轉角度(9之三角函數來 求出，因此，可將這些函數式當作上述關係資料予以記憶 ，亦可當作函數表列資料予以記憶。 滑件位置指令運算部41爲了使滑件按照動作設定部43 所決定馬達正轉時及反轉時之個別滑件動作移動，根據前 述動作，藉由運算求出每一既定伺服運算週期時間之滑件 位置之目標値。並且，將所求得滑件位置目標値輸出至指 令運算部4 2。 指令運算部42,係以減小來自前述滑件位置指令運算 部14之滑件位置目標値、與位置感測器33所檢測出之滑 件位置的偏差値之方式，根據該求出之偏差値運算馬達速 度指令，並將其輸出至伺服放大器。並且，參考前述馬達 /滑件關係資料記憶部44之滑件位置與馬達旋轉角度之關 係資料，對應滑件位置，校正此馬達速度指令運算時所用 之位置偏差增益。 18 200306908 又，亦可檢測偏心軸28之旋轉角度，使用此偏心軸28 之旋轉角度於位置反饋以代替上述滑件位置之反饋。 其次，參考圖3至圖5，說明以上構造之動作。 當小於最大行程Smax之滑件行程S1以及此時之控制 模式（相當於第1實施例之通過下死點之往復控制模式以及 相當於第2實施例之通過上死點之往復控制模式）設定完成 ，即對應於此控制模式決定動作。當通過下死點之往復控 制模式設定完成，即如圖3所示，以包含對應於滑件下死 點之偏心軸28旋轉角度0d朝反轉方向及正轉方向之分別 隔既定角度0 1、0 2，並且對應於上述設定行程si之上限 位置Ul、U2被分別求出。其次，如圖4所示，決定自其一 方之上限位置起通過下死點到達另一上限位置U2的在偏心 軸正轉之滑件動作、以及自另一上限位置U2起通過下死點 到達一方之上限位置U1的在偏心軸反轉之滑件動作。此時 ，至少在上述偏心軸反轉之加工行程AW之動作，係設定 成大致等於在偏心軸正轉之加工行程AW之連桿動作。 並且，參考預先決定之滑件位置與偏心軸旋轉角度之 關係，亦即表示滑件位置與馬達旋轉角度之機械關係的資 料，控制伺服馬達21之位置及速度，俾滑件按照上述決定 之滑件動作通過下死點往復驅動。結果，滑件經由下死點 連續往復移動於行程彼此相等之2個上限位置ui、U2之間 ，因此，在壓機1循環運轉中，伺服馬達21只要停止於上 限位置U1或U2即可。 又’當通過上死點之往復控制模式設定完成時，即如 200306908 圖3所示，以包含對應於滑件上死點之偏心軸28旋轉角度 (9 u之方式，自旋轉角度Θ u算起朝正轉方向及反轉方向之 分別隔既定角度Θ 3、0 4，並且對應於設定行程S2之下限 位置Dl、D2被分別求出。其次，如圖5所示，決定自其一 方之下限位置D1起通過上死點到達另一下限位置D2之在 偏心軸正轉之滑件動作、以及自另一下限位置D2通過上死 點到達其一方之下限位置D1之在偏心軸反轉之滑件動作。 此時，至少上述偏心軸反轉之加工行程AW之動作，係設 定成大致等於在偏心軸正轉之加工行程AW之連桿動作。 並且，如同前述，參考表示預先決定之滑件位置與馬 達旋轉角之機械關係之資料，控制伺服馬達21之位置及速 度，俾滑件按照上述決定之滑件動作’以包含上死點往復 驅動。結果，滑件經由上死點連續往復移動於行程彼此相 等之2個下限位置Dl、D2之間，因此，於壓機1運轉中’ 伺服馬達21只要停止於下限位置D1或D2即可。 又，通過上死點之往復控制模式情形之優點之一係可 針對熱變形等所造成之模具閉合高度之變化’藉滑件驅動 用伺服馬達21調整模具閉合高度。因此’於該模式情形下 ，前述下限位置Dl、D2亦包含藉由模具閉合高度調整而將 下限位置定位後之該下限位置。 而且，上述實施形態中，雖顯示以下列方式控制伺服 馬達的位置及速度，該方式係正轉時及反轉時之下降動作 或其中至少加工行程動作與定速旋轉之正轉時由肘節連桿 機構等之機械關係所決定之連桿動作大致相等’不過’不 200306908 限於此，例如，亦能以適合於加工條件、運轉條件等所設 定之動作來加以控制。 藉本發明可獲得以下功效。 由於在通過下死點之往復控制模式時，控制伺服馬達 ，俾在包含對應於下死點之偏心軸旋轉角度朝正轉側與反 轉側之對應各滑件上限位置之旋轉角度之間，將偏心軸往 復驅動，故可在自上限位置至上限位置之1循環運轉中， 使伺服馬達僅停止於前述2個上限位置。因此，相較於在 對應於下死點與一上限位置之個別旋轉角度之間反轉驅動 之方法，更能減低伺服馬達之起動、停止之頻度以及正轉 、反轉之反覆次數。由於藉此可減低伺服馬達之負荷率而 減少發熱，故可防止伺服馬達之過負荷，同時可縮短1循 環所需的時間，提高生產性。 由於在通過上死點之往復控制模式時，控制伺服馬達 ，俾在包含對應於上死點之偏心軸旋轉角度朝正轉側與反 轉側之對應於各滑件下限位置之2個旋轉角度之間將偏心 軸往復驅動，故於自下限位置至下限位置（等效地，在由上 死點定位下限位置之後，係至上死點）之1循環運轉中，可 使伺服馬達僅停止於前述2個下限位置。因此如同上述般 ，相較於較例如於對應1個下限位置與上限位置（或上死點） 之個別旋轉角度間反轉驅動之方法更可減少伺服馬達之起 動、停止之頻度以及正轉、反轉之反覆次數，故可減低伺 服馬達之負荷率，減少發熱，同時，可縮短1循環所需的 時間，提高生產性。 21 200306908 又，由於此時雖然與肘節連桿機構有關的連桿動作係 於包含下死點或上死點朝伺服馬達正轉側與反轉側並不成 對稱形狀，不過，至少於加工動作，以伺服馬達（偏心軸）反 轉時之動作大致與正轉時之連桿動作相等之方式以高精度 控制滑件之位置及速度，故無伺服馬達之往復驅動所造成 之動作變動，可獲得穩定之高加工精度。 【圖式之簡單說明】 (一） 圖式部分 圖1係本發明之控制構造方塊圖。 圖2係本發明之控制功能方塊圖。 匱I 3係表示偏心軸旋轉與滑件位置之關係的槪念圖。 圖4係以包含下死點往復驅動時之動作說明圖。 圖5係以包含上死點往復驅動時之動作說明圖。 匱I 6係應用本發明之伺服壓機之側面局部剖面圖。 Η 7係應用本發明之伺服壓機之後面局部剖面圖。 匱I 8係連桿動作例及短行程之滑件驅動例。 匱I 9係另一短行程之滑件驅動例。 壓機 滑件 基座 (二） 元件代表符號 1 3 4 200306908 7 螺軸 9 感應馬達 10 控制器 10a 記憶體 11 柱塞 12a 第1連桿 12b 第2連桿 13 三角連桿 16 切換閥 17 動作設定機構 20 滑件驅動部 21 伺服馬達 22a 第1帶輪 22b 第2帶輪 23 皮帶 27 驅動軸 28 偏心軸 33 位置感測器 34 輔助機架 41 滑件位置指令運算部 42 指令運算部 43 動作設定部 44 馬達/滑件關係資料記憶部 45 伺服放大器 23200306908 发, Faer [Technical Field of the Invention] The present invention relates to a servo motor that rotates an eccentric shaft such as a crank shaft or an eccentric shaft by a servo motor, and drives the servo pressure of a slider through a toggle link mechanism. Sliding device control device for servo press and its control method [Prior technology] In recent years, high precision (high precision in shape and size) of press-processed products and press processing for improving productivity are required. Speed up. As for the press that responds to this request, some people have proposed a linear servo press that uses a servo motor to drive the ball screw up and down in a straight line, thereby directly controlling the position and speed of the slider with high precision, and precisely sliding the slider. Drive up and down. [Summary of the Invention] However, in the structure in which the slider is driven directly up and down by the ball screw as described above, the load applied to the slider is also applied to the ball screw, so the ball screw is easy to wear. There is a problem that the durability of the ball screw greatly affects the performance of the press. Therefore, it is strongly desired to realize a servo press having a toggle link mechanism, which has both the advantages of the conventional mechanical link type press and the precise control of the sliding parts generated by the servo motor drive. Such a servo press can, for example, drive an eccentric shaft such as a crankshaft or an eccentric wheel shaft by a servo motor to rotate 200306908, and drive the slider up and down through a toggle link mechanism connected to the eccentric position of the eccentric shaft, such as in Fig. 6 and Fig. 7 respectively show a side sectional view and a rear partial sectional view of the servo press. This press 1 is driven by a servo motor 21 to rotate an eccentric shaft 28 such as a crank shaft and an eccentric shaft, and the elbow link mechanism (composed of links 13, 12a, 12b) connected to the eccentric position of the eccentric shaft 28 The slider 3 is driven up and down. In addition, when the servo motor 21 is rotated at a constant speed at a predetermined rotation speed, the eccentric length of the eccentric shaft 28, the length of each link of the toggle link mechanism, the position of the rotation center of the eccentric shaft 28, and the toggle link The predetermined link action determined by the relationship drives the slider 3. The action indicates the relationship between the position of the slider and time. Fig. 8 shows an example of the operation of the link in this case. The horizontal axis represents the rotation angle of the eccentric axis, and the vertical axis represents the slider position. As shown in Figure 8, one full rotation of the eccentric shaft corresponds to the maximum stroke Smax of the slider, that is, the stroke from the top dead center to the bottom dead center. Therefore, when the servo motor is continuously rotated in one direction, the slider is at the maximum The stroke Smax moves up and down. Although the necessary stroke may also be a short stroke depending on the mold shape and processing conditions, such as the short stroke S0 shown in the figure, in this case, if the slider is still driven with the maximum stroke Smax, not only power is wasted, In addition, there is a problem that the productivity cannot be improved because the number of processing strokes (the number of processing cycles per minute) cannot be increased. Therefore, the slider must be controlled so that the slider stroke is smaller than the maximum stroke Smax. On the other hand, in order to make use of the advantages of the link-action type press, there is a processing method that uses the strength of the pressure capability of the toggle link mechanism to the bottom dead center. In this case, it can be Use the point as a reference to set the slider stroke, and control the slider so that it passes through the bottom dead center. As far as the control method of 200306908 in this case, the servo motor can be controlled to reciprocate between the angle of the eccentric shaft corresponding to the bottom dead point (0 d in FIG. 8) and the angle corresponding to the necessary stroke S0 (β 0 in FIG. 8). between. However, if this control method is used, since the slider must be stopped at the bottom dead center and the upper limit position U0 of the slider during one cycle of the press, the acceleration and deceleration of the servo motor and the forward rotation and reverse rotation are frequently performed. Due to the increase of the motor load, overload is easy to occur, and at the same time, it is difficult to increase the number of slider strokes and reduce productivity. In addition, in order to position the lower limit position of the slider and drive the slider with high accuracy, for example, as shown in FIG. 9, a predetermined position in front of the bottom dead center can be controlled as the lower limit position Da, but the same is true in this case. The ground must stop the slider at two of the upper limit position Ua and the lower limit position Da corresponding to the set stroke Sa, so the same problem described above occurs. The present invention focuses on the developers of the above problems, and its object is to provide a slider control device and a control method of a servo press which can set an arbitrary slider stroke and can increase the number of press strokes. Means, function and effect for solving the problem In order to achieve the above object, the first invention is a slider control device for a servo press, which is characterized by having a servo motor (21) for driving the slider (3) An eccentric shaft (28) rotationally driven by the servo motor (21); a toggle link mechanism provided between the eccentric position of the eccentric shaft (28) and the slider (3); and a controller (10), which When the eccentric shaft (28) is driven to rotate forward and backward at a rotation angle including the eccentric shaft (28) corresponding to the bottom dead point or the top dead point of the slider, the speed of the servo motor (21) is controlled to be approximately the same in the forward and reverse directions. The machining action controls the slide 200306908. The third invention is a method invention corresponding to the first invention of the device invention. It is a slide control method of a servo press. The eccentric shaft is driven by a servo motor to rotate, and it passes through the elbow. The joint link mechanism drives the slider. This method controls the speed of the servo motor when the eccentric shaft is driven to rotate forward and backward at an angle of rotation including an eccentric shaft corresponding to the bottom dead point or top dead point of the slider. Machining action to control the sliderAccording to the first or third invention, when the reciprocating control mode through the bottom dead point or the reciprocating control mode through the top dead point, the position (rotation angle) of the eccentric shaft including the bottom dead center or the top dead center is included. The eccentric shaft is driven to reciprocately rotate between forward and reverse positions corresponding to the upper limit position or lower limit position of the predetermined stroke, whereby the slider continuously moves from the upper limit position to the upper limit position through the bottom dead point. , Or from the lower limit position, through the upper dead point, continuously move to the lower limit position. Therefore, in the 1 cycle of the press, the slider only stops at the upper limit position or the lower limit position, so the number of acceleration, deceleration, forward rotation and reverse rotation of the servo motor is repeatedly reduced to prevent overload of the servo motor. Since the time required for one cycle can be shortened, the number of processing strokes can be increased and productivity can be increased. Furthermore, at this time, since the speed of the servo motor is controlled in such a way that the movement of the machining stroke is approximately equal during the forward and reverse rotation of the eccentric shaft, it is possible to eliminate the change of the machining action caused by repeated forward and reverse rotation. , And often drive the slider with a stable link action. As a result, the quality of the processed product can be maintained with high accuracy. The second invention is an action setting mechanism provided in the first invention, and the action data includes at least the stroke of the slider; and the controller calculates after the completion of the stroke setting of the 200306908 slider whose maximum stroke is smaller than the maximum stroke of the slider. An action that rotates the eccentric shaft forward and backward between the angles corresponding to the stroke toward the forward rotation side and the reverse rotation side, respectively, from the rotation angle of the eccentric shaft corresponding to the bottom dead point or the top dead point of the slider. In addition, the fourth invention is the third invention. After the stroke setting of the slider is smaller than the maximum stroke is completed, the rotation angle of the eccentric shaft corresponding to the bottom dead point or the top dead point of the slider is counted toward the forward rotation side. Between the angles corresponding to the stroke and the reverse side, the eccentric shaft rotates forward and backward. According to the second or fourth invention, since the stroke can be set to be smaller than the maximum stroke in accordance with the processing conditions, operating conditions, and the like, the eccentric shaft can be driven back and forth between the rotation angles of the eccentric shaft corresponding to the set stroke, so it is flexible. In response to changes in stroke, productivity can be improved. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 6 and Fig. 7 are a partial side sectional view and a rear partial sectional view of a servo press to which the present invention is applied, respectively. In FIGS. 6 and 7, the press 1 is a servo press, and the slider 3 is driven by a servo motor 21. The slider 3 is supported on the substantially central part of the main body frame 2 of the press 1 so as to be able to move up and down. A support beam 5 mounted on the bed 3 is arranged below the slider L. In the hole formed in the upper part of the slider 3, the main body of the screw closing height adjustment screw shaft 7 is inserted in a manner to prevent loosening and to be rotatable. The screw portion 7a of the screw shaft 7 is exposed upward from the slider 3, and is screwed with the female screw portion of the lower portion of the plunger 11 provided above the screw shaft 7. 200306908 A worm gear 8a of a worm gear 8 is mounted on the outer periphery of the main body of the screw shaft 7. The worm 8b of the worm gear 8 screwed with the worm gear 8a is connected to the output of the induction motor 9 installed at the rear of the slider 3 through the gear 9a. axis. The induction motor 9 'is arranged in a flat shape with a short axial length and is miniaturized. The upper pin 19 of the plunger 11 is rotatably connected to one end of the first link 12a, and the other end of the first link 12a is rotatably connected to the second end of the main body frame 2 Between the other ends of the connecting rods 12b, two connecting holes 14a, 14b provided on the side of the three-axis connecting rod 13 are freely connected. The connecting hole on the other side of the triaxial link 13 is rotatably connected to the eccentric shaft 28 of the slider driving portion 20 described in detail later. The first link 12a, the second link 12b, and the triaxial link 13 constitute a toggle link mechanism. The servo motor 21 for slider driving is mounted on the side of the main body frame 2 with the shaft centering in the left-right direction of the press, and the belt 23 (usually composed of a moving belt) is wound on the first of the output shafts of the servo motor 21 Between the pulley 22a and the second pulley 22b attached to the intermediate shaft 24, the intermediate shaft 24 is rotatably provided above the servo motor 21 with the shaft center facing the press in the left-right direction. The drive shaft 27 is rotatably supported on the main body frame 2 above the intermediate shaft 24. A gear 26 mounted on the end of the drive shaft 27 is engaged with a gear 25 mounted on the intermediate shaft 24. An eccentric shaft 28 is formed at an axially intermediate portion of the drive shaft 27. The other side of the three-axis link 13 is rotatably connected to the outer peripheral portion of the eccentric shaft 28. An oil chamber 6 is formed in the slider 3 so as to be sealed from the lower end surface of the screw shaft 7. The oil chamber 6 is connected to the switching valve 16 through an oil passage 6a formed in the slider 3. The switching valve 16 switches the supply and discharge of the operating oil to the inside of the oil chamber 6 11 200306908. During the press working, oil is supplied into the oil chamber 6, and the tight pressure at the time of pressurization is transmitted to the slider 30 through the oil in the oil chamber 6. If an overload is applied to the sliding member 3, and the oil in the oil chamber 6 exceeds the predetermined pressure, the oil will return to the oil tank from the safety valve in the figure, and the sliding member 3 buffers the predetermined amount, so that the sliding member 3 and the mold will not be damaged. A pair of brackets 31 and 31 protruding from the upper and lower portions toward the side surface of the main body frame 2 are mounted on the face after the slider 3, and a position detector 32 is mounted between the pair of brackets 31 and 31. The body portion of the position sensor 33 such as a linear scale is inserted into the position detection lever 32 of the position detection scale portion so that it can move up and down freely. The position sensor 33 is fixed to an auxiliary frame 34 provided on a side portion of the main body frame 2. This auxiliary frame 34 is formed vertically in the up-down direction. The lower portion is mounted on the side of the main body frame 2 by bolts 35. The upper portion is supported by the bolts 36 inserted into the long holes in the upper and lower directions. The pair of front and rear support members 37 and 37 are abutted and supported. The auxiliary frame 34 is constructed to fix only the upper and lower sides (in this example, the lower side) to the main body frame 2 and support the other side to move up and down freely, so it is not affected by the temperature of the main body frame 2 due to the temperature. The effect of change while scaling. Thereby, the aforementioned position sensor 33 is not affected by the expansion and contraction of the main body frame 2 due to temperature changes, and the position of the slider and the mold closing height can be correctly detected. FIG. 1 is a block diagram of the hardware structure of the control device of the present invention. This control device includes a controller 10, an operation setting mechanism 17, a memory 10a, a position sensor 33, a servo amplifier 45, and a servo motor 21 for slider driving. The action setting mechanism 17 can set the slider action, and it has a switch for setting the slider 12 and the ten-key (ten-key) of the slider stroke number (SPM), or from an external storage medium such as a 1C card (memory There is a data input device for preset slider movement data). It may also be constituted by a communication device that transmits and receives data via wireless or communication lines. The memory 10a stores the slider operation data (stroke, number of strokes, etc.) completed as described above, and also stores the relationship data of the motor rotation angle and slider position for slider control. The relationship between the rotation angle of the motor and the position of the slider is connected to the elbow by the length of each link 12a, 12b, 13 of the aforementioned toggle link mechanism, the eccentric length of the eccentric shaft 28, and the rotation center position of the eccentric shaft 28. The data obtained by the functional formula determined by the mechanical dimensions such as the relationship between the rods can be memorized by the function itself, or the functional formula can be made into list data for storage. The aforementioned position sensor 33 outputs the detected position of the slider to the controller 10. The controller 10 is composed of a computer device or a high-speed computing device such as a PLC (programmable logic controller, so-called programmable sequencer). The controller 10 refers to the data on the relationship between the motor rotation angle and the position of the slider stored in the aforementioned memory 10a, and according to the data of the slider stroke and the number of slider strokes set by the aforementioned motion setting mechanism Π, In the manner in which the set action is used to move, the calculation processing described in detail later is performed, the speed command of the servo motor 21 is obtained, and it is output to the servo amplifier 45. The motor rotation angle from the servo motor rotation angle sensor of the figure is fed back to the servo amplifier 45. The servo amplifier 45 calculates the deviation 値 of the speed command from the controller 10 and the speed feedback signal obtained from the rotation angle of the motor, and controls the servo motor 21 based on the obtained deviation 减小 to reduce the deviation 値. Thereby, the position and speed of the slider can be controlled with high accuracy. Next, according to the control function block diagram shown in FIG. 2 and the explanatory diagrams of the slider control method shown in FIGS. 3 to 5 respectively, each control function of the control device will be described. Among them, FIG. 3 shows the relationship between the rotation of the eccentric shaft 28 and the position of the slider. FIG. 4 is an operation explanatory diagram when the bottom dead center is reciprocated, and FIG. 5 is when the top dead center is reciprocated. Operation Description Figure 0 First, the basic idea of the control method of the present invention will be described. The first embodiment of the slider control method of the present invention describes a case where the eccentric shaft 28 is driven to reciprocate in a forward and reverse rotation manner by including a position corresponding to the bottom dead point of the slider. The second embodiment describes a method including The position of the dead point is the case where the eccentric shaft 28 is driven back and forth in a forward and reverse rotation manner. As shown in FIG. 3, the rotation angle of the eccentric shaft 28 corresponding to the bottom dead point of the link is referred to as 0d (usually greater than 180 degrees), and the rotation angle of the eccentric shaft 28 corresponding to the top dead point is referred to as 0 u (usually less than 360 degrees). In the first embodiment, the eccentric shaft 28 is rotated at a predetermined angle from the angle 0d (hereinafter referred to as the reversing direction) at a predetermined rotation angle, and from the angle toward the positive direction (hereinafter referred to as the forward rotation direction) at a predetermined interval. The rotation of the angle 02 is reciprocated between the rotation angles, so that the slider is continuously reciprocated between one upper limit position U1 and the other upper limit position U2 so as to include a bottom dead point. Here, the upper limit position IΠ corresponding to an angle separated by a predetermined angle 01 in the reverse direction and the upper limit position U2 corresponding to an angle separated by a predetermined angle 02 in the forward direction are the same positions, and these upper limit positions Ul, U2 and the bottom die The distance between the points corresponds to the set stroke S1. 200306908 In the second embodiment, the rotation angle of the eccentric shaft 28 at the eccentric shaft 28 corresponding to the top dead center is 0 u, and the rotation angle is separated by a predetermined angle β 3 in the reverse direction and the predetermined angle Θ 3 is set in the forward direction. The reciprocating driving is performed between the rotation angles, so that the slider is continuously reciprocatingly driven between the lower limit position D1 and another lower limit position D2 in a manner including the upper dead point. Here, the lower limit position D1 corresponding to an angle separated by a predetermined angle 0 3 in the reverse direction and the lower limit position D2 corresponding to an angle separated by a predetermined angle θ 4 in the forward direction are the same positions. These lower limit positions D1, D2 and The distance between the top dead centers corresponds to the set stroke S2. As mentioned above, the link action determined by the relationship between the eccentric length of the eccentric shaft 28, the length of each link of the toggle link mechanism, the position of the center of rotation of the eccentric shaft 28 and the toggle link is shown in FIG. Including the bottom dead point or the top dead point toward the forward rotation side and the reverse rotation side, the relationship between the rotation angle 0 and the position of the slider is asymmetric and different. That is, on the reverse side from the bottom dead center, the position of the slider changes slowly with respect to the rotation angle 0 which changes at a certain speed, and on the contrary, the position of the slider changes abruptly on the forward rotation side. Also, on the forward rotation side from the top dead center, the slider position is slowly changed, and conversely, on the reverse rotation side, the slider position is suddenly changed. However, since the speed of the slider during the processing stroke (near the position where it abuts the workpiece) is a very important forming condition for the quality of the product, the speed of the slider during the processing stroke must be equalized even in the case of forward and reverse rotation driving. Therefore, in the first embodiment, the sliding stroke of the slider moving downward from the upper limit position U1 or the upper limit position U2 of the stroke S1 to the bottom dead center is at least during the processing stroke. The servo motor 21 controls the rotation speed of the eccentric shaft 28, and precisely controls the position and speed of the slider. 15 200306908 In the second embodiment, the sliding stroke of the slider moving from the top dead center to the lower limit position D1 or the lower limit position D2 of the stroke S2 is at least during the processing stroke. The motor 21 controls the eccentric shaft 28 and precisely controls the position and speed of the slider. In order to achieve the above operation, each functional unit shown in FIG. 2 is provided. The action setting unit 43 determines the relationship between the control execution time t and the slider position P based on the action data such as the slider drive mode, slider stroke S1, and stroke number N (SPM) set by the aforementioned motion setting mechanism 17. Actions. More specifically, when the slider driving mode is the reciprocating control mode of driving the slider through the bottom dead point in the form of the first embodiment, it is necessary to determine the upper limit position U1 or U2 including the bottom dead point via the bottom dead point. Point to the other upper limit position U2 or U1. That is, as shown on the left side of FIG. 4, when the eccentric shaft 28 is driven in the forward direction by the servo motor 21, and the slider is reciprocated from the upper limit position U1 through the bottom dead point to the upper limit position U2, it is determined to be at a certain speed. Forward rotation (or at least the maximum motor speed during the ascent stroke). As a result, the slider is lowered by the slow link operation between the upper limit position U1 and the bottom dead point as described above, and is raised by the sharp rise operation between the bottom dead point and the upper limit position U2. The time required for one cycle at this time is determined by the previously set number of strokes N. As shown on the right side of FIG. 4, when the eccentric shaft 28 is driven in the reverse direction, and the slider is reciprocated from the upper limit position U2 to the upper limit position U1 through the bottom dead center, in order to move the upper limit position U2 to the lower limit Between the points, the slider is lowered at a link operation that is as slow as the upper limit position U1 to the bottom dead point when driving in the forward rotation direction, and a link operation that is substantially equal to this is determined. Moreover, the actions of the machining stroke AW of only at least two 16 200306908 can be made equal here. In addition, from the bottom dead center to the upper limit position, it is determined to rotate and drive in the reverse direction at a certain speed (usually the maximum speed). Thereby, the machining operation during the reverse rotation can be made substantially equal to that during the forward rotation. In addition, when the slider driving mode is a reciprocating control mode of driving the slider through the top dead point by the type of the second embodiment, it is determined to pass the top dead point from the lower limit position D1 or D2 including the top dead point. To the other upper limit position D2 or D1. That is, as shown on the left side of FIG. 5, when the eccentric shaft 28 is driven by the servo motor 21 in the forward direction first, and the slider is controlled between the top dead center and the lower limit position D2, it is decided to forward at a certain speed. action. Thereby, the slider moves down from the top dead center to the lower limit position D2 by a slow link motion. Next, the servo motor 21 drives the eccentric shaft 28 in the reverse direction, and controls the slider from the lower limit position D2 through the upper dead point to the lower limit position D1. At this time, it is decided to reverse the action at a certain speed (usually the maximum speed) between the lower limit position D2 and the upper dead point. In addition, in order to control the speed of the servo motor 21 between the upper dead point and the lower limit position D1, a slow link operation is determined to be approximately the same as the upper dead point to the lower limit position D2 when the forward rotation direction is driven. Moreover, only the operations of at least two machining strokes AW can be made substantially the same here. Thereby, the slider is raised in an operation substantially symmetrical to the above-mentioned top dead center to the lower limit position D2, and then lowered in approximately the same operation. Next, as shown on the right side of FIG. 5, the eccentric shaft 28 is driven in the forward direction, and when the slider is reciprocated from the upper limit position D1 through the upper dead point to the lower limit position D2, it is determined between the lower limit position D1 and the upper dead point. Action at forward speed at a certain speed (17 200306908 is usually the maximum speed) determines the action from forward dead point to lower limit position D2 as described above at forward speed at a certain speed. Hereinafter, the above operations are repeatedly controlled. The motor / slider relationship data storage unit 44 stores data indicating the relationship between the rotation angle of the servo motor 21 and the position of the slider in the memory 10a. And if, as shown in FIG. 8 for example, the relationship between the rotation angle of the servo motor 21 and the position of the slider is represented by the relationship between the rotation angle 0 (0 degrees to 360 degrees) of the eccentric shaft 28 and the slider, it is easy to understand the The link moves. And because the function formula of this link action is the length of each link of the aforementioned toggle link mechanism, the eccentric length of the eccentric shaft 28, the relationship between the position of the rotation center of the eccentric shaft 28 and the toggle link mechanism, and the rotation of the eccentric shaft 28 The angle (triangular function of 9) is obtained. Therefore, these functional formulas can be memorized as the above-mentioned relational data, and can also be memorized as function table data. The slider position command calculation unit 41 is set to make the slider according to the action. The individual slider movements during forward and reverse rotations determined by the unit 43 are determined, and the target position 动作 of the slider position for each predetermined servo operation cycle time is calculated by calculation based on the aforementioned movements. The workpiece position target 値 is output to the command computing unit 42. The command computing unit 42 is to reduce the slider position target 値 from the slider position command computing unit 14 and the slider position detected by the position sensor 33. According to the calculated deviation, the motor speed command is calculated and output to the servo amplifier, and the slip of the motor / slider relationship data storage unit 44 is referred to. The relationship between the position of the motor and the rotation angle of the motor, corresponding to the position of the slider, corrects the position deviation gain used in the calculation of this motor speed command. 18 200306908 In addition, the rotation angle of the eccentric shaft 28 can also be detected, and the rotation angle of the eccentric shaft 28 can be used. The position feedback is used to replace the feedback of the slider position. Next, the operation of the above structure will be described with reference to FIGS. 3 to 5. When the slider stroke S1 is smaller than the maximum stroke Smax and the control mode at this time (equivalent to the first embodiment) The reciprocating control mode through the bottom dead point and the equivalent of the reciprocating control mode through the top dead point in the second embodiment) are set, that is, the action is determined corresponding to this control mode. When the reciprocating control mode through the bottom dead point is set, That is, as shown in FIG. 3, the rotation angle 0d including the eccentric shaft 28 corresponding to the bottom dead point of the slider is separated from the reverse direction and the forward direction by a predetermined angle of 0, 0, and corresponds to the above-mentioned set stroke si. The upper limit positions Ul and U2 are obtained separately. Next, as shown in FIG. 4, it is determined that the upper limit position U1 reaches the other upper limit position U2 through the bottom dead point from one of the upper limit positions. Movement of the eccentric shaft in forward rotation, and movement of the eccentric shaft in reverse at the upper dead position U1 from the other upper limit position U2 to one of the upper limit positions U1. At this time, at least in the above-mentioned eccentric shaft reverse processing The movement of the stroke AW is set to be approximately equal to the movement of the connecting rod of the machining stroke AW that rotates forward on the eccentric shaft. Also, referring to the relationship between the predetermined position of the slider and the rotation angle of the eccentric shaft, that is, the position of the slider and the rotation of the motor The data of the mechanical relationship of the angle controls the position and speed of the servo motor 21, and the slider moves back and forth through the bottom dead point according to the slider action determined above. As a result, the slider continuously reciprocates through the bottom dead point until the strokes are equal to each other. Between the upper limit positions ui and U2, the servo motor 21 only needs to stop at the upper limit positions U1 or U2 during the cycle operation of the press 1. When the setting of the reciprocating control mode through the top dead point is completed, that is, as shown in 200306908 and FIG. 3, the rotation angle of the eccentric shaft 28 corresponding to the top dead point of the slider (9 u, the rotation angle θ u is calculated). The forward and reverse directions are separated by a predetermined angle Θ 3, 0 4 and corresponding to the lower limit positions D1 and D2 of the set stroke S2. Secondly, as shown in FIG. From the lower limit position D1, the slider moves forward through the eccentric axis through the upper dead point to reach another lower limit position D2, and when the lower limit position D2 reaches the lower limit position D1 through the upper dead point, it reverses on the eccentric axis. At this time, at least the operation of the machining stroke AW in which the eccentric shaft is reversed is set to be approximately equal to the movement of the connecting rod in the machining stroke AW in which the eccentric shaft is normally rotated. Also, as mentioned above, the reference indicates a predetermined sliding Data on the mechanical relationship between the position of the parts and the rotation angle of the motor, control the position and speed of the servo motor 21, the slider moves in accordance with the above-determined slider action to reciprocally drive including the top dead point. As a result, the slider passes the top dead point Continue to move back and forth between the two lower limit positions D1 and D2 with equal strokes. Therefore, during the operation of the press 1, the 'servo motor 21' only needs to stop at the lower limit positions D1 or D2. Moreover, the reciprocating control through the upper dead point One of the advantages of the mode situation is that the mold closing height can be adjusted for the change in mold closing height caused by thermal deformation, etc. Therefore, in the case of this mode, the aforementioned lower limit positions D1 and D2 also include The lower limit position is determined by positioning the lower limit position by adjusting the mold closing height. In addition, in the above embodiment, although the position and speed of the servo motor are controlled in the following manner, this method is a downward movement during forward rotation and reverse rotation. Or at least the movement of the machining stroke and the forward rotation of the fixed-speed rotation determined by the mechanical relationship of the toggle link mechanism are approximately equal to each other, but '2003908' is not limited to this. For example, it can also be adapted to processing conditions, The operation is set to control the operation conditions, etc. The following effects can be obtained by the present invention. Because of the reciprocating control mode of passing through the bottom dead center Control the servo motor to drive the eccentric shaft back and forth between the rotation angle including the rotation angle of the eccentric shaft corresponding to the bottom dead point toward the upper limit position of the forward rotation side and the reverse rotation side, so it can be driven from the upper limit. During the 1-cycle operation from the position to the upper limit position, the servo motor is stopped only at the two upper limit positions. Therefore, compared with the method of reversing the drive between the individual rotation angles corresponding to the bottom dead point and an upper limit position, It can reduce the frequency of starting and stopping the servo motor and the number of times of forward and reverse rotation. Because it can reduce the load rate of the servo motor and reduce heat generation, it can prevent the overload of the servo motor and shorten the cycle time. As the reciprocating control mode of the top dead center is passed, the servo motor is controlled, and the sliders corresponding to the rotation angle of the eccentric shaft corresponding to the top dead center toward the forward rotation side and the reverse rotation side correspond to each slider. The eccentric shaft is driven back and forth between the two rotation angles of the lower limit position, so from the lower limit position to the lower limit position (equivalently, after positioning the lower limit position from the upper dead point, the To the top dead center), the servo motor can be stopped only at the above two lower limit positions during one cycle of operation. Therefore, as described above, the frequency of starting and stopping the servo motor and the frequency of forward rotation can be reduced compared with the method of reverse driving between the individual rotation angles corresponding to a lower limit position and an upper limit position (or top dead point), for example. The number of times of reverse rotation can reduce the load rate of the servo motor and reduce heat generation. At the same time, it can shorten the time required for one cycle and improve productivity. 21 200306908 At this time, although the link operation related to the toggle link mechanism is based on the bottom dead center or top dead center, the forward and reverse sides of the servo motor are not symmetrical, but at least the machining operation The position and speed of the slider can be controlled with high precision in a manner that the action of the servo motor (eccentric shaft) in the reverse direction is approximately equal to the movement of the connecting rod in the forward direction, so there is no movement change caused by the reciprocating drive of the servo motor. Obtain stable and high machining accuracy. [Brief description of the drawings] (1) Schematic part Figure 1 is a block diagram of the control structure of the present invention. FIG. 2 is a block diagram of a control function of the present invention. I 3 is a conceptual diagram showing the relationship between the rotation of the eccentric shaft and the position of the slider. FIG. 4 is an operation explanatory diagram when reciprocating driving is performed including the bottom dead center. FIG. 5 is an operation explanatory diagram when reciprocating driving including the top dead center. The I 6 is a partial cross-sectional side view of the servo press to which the present invention is applied. Η 7 is a partial cross-sectional view of the rear surface of the servo press to which the present invention is applied. Example of I 8 series linkage operation and short stroke drive example. The I 9 is another example of a short-stroke slider drive. Press slide base (2) Symbols for components 1 3 4 200306908 7 Screw shaft 9 Induction motor 10 Controller 10a Memory 11 Plunger 12a 1st link 12b 2nd link 13 Delta link 16 Switching valve 17 action Setting mechanism 20 Slider drive unit 21 Servo motor 22a First pulley 22b Second pulley 23 Belt 27 Drive shaft 28 Eccentric shaft 33 Position sensor 34 Auxiliary frame 41 Slider position command calculation unit 42 Command calculation unit 43 operates Setting section 44 Motor / slider relationship data memory section 45 Servo amplifier 23