A7 550320 五、發明說明（f ) 【技術領域】 本發明係關於主要在使用拷克車作端緣包縫縫製時， 用來封上下璺合之2片被縫製布料中至少一方之布料之端 緣部是否從既定之縫製位置脫離，作光學方式檢測而通知 縫製作業者等，以防止縫製不良品之發生的縫紉機之漏針 檢測裝置。 【習知技術】 使用拷克車進行上下疊合之縫製布料之端緣包縫等之 縫製時，特別因下布料難於注視且縫製中途之位置修正非 常困難，故其端緣部向正交於縫製進行方向之布料寬度方 向移位，而從既定之縫製位置（縫跡）脫離，所謂漏針，就 容易發生。如上所述之漏針對縫製品而言係致命性缺點。 以光學方式檢測如上所述之漏針而防止縫製不良品之 發生的裝置，習知，例如在實公昭59 — 25349號公報等所 揭示，已知悉使用光透過式之光電感測器來檢測漏針。在 上述公報等所揭示之習知之漏針檢測裝置，係使用光透過 式之光電感測器（由對縫製布料投光光線的投光器與對應該 投光器受光透過縫製布料之光線的受光器所組成），藉由檢 測縫製布料之重疊片數，即，檢測上布料與下布料是否重 疊而變化之透過光量之增減，來檢測漏針。 然而，使用光透過式光電感測器之習知之漏針檢測裝 置之情形，因藉由透過光量之增減來檢測漏針之有無，每 於厚度或光透過特性相異之縫製布料之種類變更時，需要 3 ------II--------I----訂--------I (請先閱讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國家標準（CNS)A4規ί各（210 X 297公釐) — ' A7 550320 五、發明說明（V) 將光電感測器之感度調整(校正)等麻煩且費時的作業預先 作好，故當作少量多種之布料之縫製所使用的縫紉機之漏 針檢測裝置，就有缺乏實用性之問題。 【發明之槪要】 本發明，係鑒於上述實情所得者，其目的在於提供： 即使要縫製厚度或光透過性相異之任何種類之布料之情形 ，不需要麻煩之感度調整作業，能確實且正確地檢測漏針 之發生的縫紉機之漏針檢測裝置。 爲達成上述目的，申請專利範圍第1項所述之發明相 關的漏針檢測裝置，係設置於針板之落針部之附近位置， 將上下疊合之縫製布料之端緣部以光學方式檢測其是否從 既定之縫製位置脫離，其特徵在於設置有： 反射式光電感測器，設於針板之上方及下方位置，個 別檢測上布料之端緣部及下布料之端緣部之有無； 反射部，分別形成於縫製布料導引構件之上下面；用 來將來自上下之光電感測器之投光光線分別向上方及下方 反射；該縫製布料導引構件，係介在上下之布料間，並且 於縫製布料導引作用位置、與從針板離開之非導引作用位 置之間可自由變更位置；用來導引上下布料往縫製進行方 向移動；及 檢測機構，處理上下之反射式光電感測器所得之兩檢 測訊號來判定縫製布料之漏針之有無，接受其判定結果而 動作。 4 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公楚） " ---— — — — —----- · I I (請先閲讀背面之注意事項再填寫本頁) 訂： --線· 550320 B7 五、發明說明（$ ) 根據上述構成之申請專利範圍第1項所述之發明，因 個別檢測上布料及下布料之端緣部之有無，藉由該兩檢測 訊號之訊號處理來判定縫製布料之漏針之有無，根據其判 定結果使檢測機構動作，故發揮如下效果：將縫製布料之 厚度（厚薄）或布料固有之光透過性相異之任何種類之布料 爲縫製對象時，亦不需要在事前進行麻煩之光電感測器之 感度g周整’將如上布料及下布料之任何一方之端緣部從既 定之縫製位置脫離的漏針之發生，能確實且正確地檢測。 又’在上述構成之縫紉機之漏針檢測裝置，藉由將來 自上下之光電感測器之投光光線分別向上方及下方反射的 反射部’如申請專利範圍第1項所述，藉由採用分別形成 於縫製布料導引構件之上下面(介在上下之布料間且導引上 下布料使其沿縫製進行方向移動)的構成，即使是薄布料， 能將上下布料順沿導引構件以不發生鬆弛之方式移動導引 著’使向上方及下方之投光光線之反射作用爲確實而提高 上下兩光電感測器的布料端緣部之有無之檢測性能。 又’在如上述具備附上下反射面導引構件之縫紉機之 漏針檢測裝置，如申請專利範圍第1項所述，藉由使導引 構件可於縫製布料導引作用位置與從針板離開之非導引作 用位置之間自如地變更位置之構成，即使縫製對象物爲筒 狀縫製物之情形，不使導引構件變成既定之縫製之障礙， 或變成縫製後之縫製物之取出之妨礙。即，筒狀縫製物之 縫製已進行而其縫製開始端部來至落針部前面時，藉由將 導引構件變更{^置（退避）至非導引作用位置，不使縫製開 5 本紙張尺度適用中國國豕標準（CNS)A4規格（210 X 297公爱) ---- ---------------------訂---------線 (請先閱讀背面之注意事項再填寫本頁) 550320 A7 ______ 五、發明說明（ι|) 始端部掛住導引構件，而能確實縫製至縫製結束端部，並 且將縫製後之筒狀縫製物不受導引構件之阻礙而能從縫製 處取出，使該漏針檢測裝置亦能有效適用於筒狀縫製物。 在上述構成的縫紉機之漏針檢測裝置，如申請專利範 圍第2項所述，較佳者，上述上下之反射式光電感測器， 係設置於比切齊縫製布料之端緣的切刀機構更靠縫製進行 方向前方之位置，伴隨切刀機構向縫製進行方向的正交方 向移動，配合切齊位置之調整，而可調整上下之反射式光 電感測器之位置。 根據採用如上構成之申請專利範圍第2項所述之發明 ，除上述效果外再加上：以切刀機構之移動調整包縫寬度 時，伴隨於此而能使上下兩光電感測器位置調整於對應切 刀機構之切齊位置的既定之檢測位置，即使進行包縫寬度 之調整，亦能確實地保持既定之漏針檢測機能。 特別，如申請專利範圍第3項所述，作爲光電感測器 之位置調整之構成，藉由使下側之光電感測器被支撐於切 刀機構之下切刀座，伴隨爲調整切齊位置而移動下切刀座 ，使下側之光電感測器能與下切刀座一體調整位置，能使 爲調整包縫寬度當然要進行之下切刀座的移動量與下側之 光電感測器的位置調整量完全一致，在包縫寬度之調整後 ，另外要調整下側之光電感測器之位置的費事則變成不需 要，能在確保著既定之漏針檢測機能之狀態下容易且迅速 進行包縫寬度調整。又，上側之光電感測器，藉由將來自 伴隨下切刀座之移動一體調整位置之下側之光電感測器的 6 本紙張尺度適用中國國家標準（CNS)A4規格（21〇 X 297公釐） -------— II-----------訂---------線 (請先閱讀背面之注意事項再填寫本頁) A7 550320 五、發明說明（^ ) 投光光線爲照準來調整位置，能容易且正確地調整包縫寬 度調整後之既定之檢測位置。 又，在上述構成之縫紉機之漏針檢測裝置’上下之反 射式光電感測器中至少下側之光電感測器’如申請專利範 圍第4項所述，使用光纖感測器’藉由採用使該光纖感測 器被固定支撐於切刀機構之下切刀座的構成’將該下側之 光電感測器以確保既定之感測機能之狀態，安裝在因下切 刀座等之切刀機構用構件之存在而使安裝空間不太足夠之 場所。 進一步，上述構成之縫紉機之漏針檢測裝置的反射部 ，如申請專利範圍第5項所述，以回歸反射帶形成爲最簡 單，且，能得確實之檢測機能，然而除此之外，亦可例如 將導引構件之上下面作鏡面加工來形成反射面。 又，如申請專利範圍第6項所述，藉由上下之光電感 測器係使用回歸反射型之光電感測器，分別具有偏光濾波 器於其投光、受光元件之前面，在投光側通過偏光濾波器 而僅投光橫方向或縱方向之波之光線，並且，在受光側通 過偏光濾波器而僅受光縱方向或橫方向之波之反射光線， 並且，上述反射部之反射面(使來自上下之光電感測器之投 光光線向上方及下方反射)係使用回歸反射帶，具有僅將所 投光之橫方向或縱方向之波之光線，偏光成所有方向之波 之光線而反射之機能，即使在投光位置存在有光澤之物體 或部位，或布料本身爲光反射性強者，能明確區分來自這 些之反射光（外亂光)與來自反射帶之反射光，藉此，上下 7 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐) 一 ---------------------訂-------- (請先閱讀背面之注意事項再填寫本頁) 550320 A7 B7 五、發明說明（ 光電感測器僅正確檢測上下布料的端緣部之有無，沒有誤 檢測，誤檢測動作，能顯著提高既定之漏針檢測精度。 本發明之其他目的及效果，在以下所要說明之實施例 將可更明確。 【圖式之簡單說明】 圖1 ’係具備本發明之漏針檢測裝置之拷克車之要部 的槪略立體圖。 圖2，係上述縫紉機之要部的俯視圖。 圖3，係上述縫紉機之要部的前視圖。 圖4，係上述縫紉機之要部的右側視圖。 圖5，係表示上述縫紉機之切刀機構之詳細構成之要 部的分解立體圖。 圖6 ’係表不含有上下之反射式光電感測描1之漏針才双 測裝置之電路構成的方塊圖。 圖7，係說明包縫時之漏針檢測動作的流程圖。 圖8(A)、（B)，係說明包縫時之上下布料之端緣部之檢 測狀況的槪略側視圖。 【符號說明】 1 2 3 6 交叉板 針板 機框 落針部 衣紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） --------------裳--- (請先閱讀背面之注意事項再填寫本頁) · -線- 550320 A7 B7 五、發明說明（1) 9 9A 9B 17 19 25 26 33 34、35 40、41 42 43 44 45 Μ Ml M2 SI 、 S2 、 S3 54 55 W Wu Wd We 切刀機構 上切刀 下切刀 下切刀座裝配具 下切刀座 上側之反射式光電感測器 下側之反射式光電感測器 導引構件 回歸反射帶 放大器 控制部 容許漏針設定器 旋轉檢測器 漏針通知機構 縫紉機 容許運針數 檢測運針數 檢測訊號 設定訊號 輸出訊號 縫製布料 上布料 下布料 端緣 ---------I----· I I (請先閱讀背面之注意事項再填寫本頁) •線' 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） A7 550320 五、發明說明（t ) Y 縫製進行方向 【發明之較佳實施形態】 以下，根據圖式說明申請專利範圍第1項至第9項所 述之本發明之實施形態。 圖1，係具備本發明相關之漏針檢測裝置之拷克車(縫 紉機)Μ之要部的槪略立體圖，圖2，係上述縫紉機Μ之要 部的俯視圖。在該拷克車Μ之交叉板1，以其上面與交叉 板1爲同一面之狀態，固定針板2。在該針板2之下部， 且’挾住縫針(透過針固定件裝配於上下往復運動自如地支 撐在機框3的針棒4之下端部(省略圖示))之落針部6之前 後位置，配設前•後之進給齒（用來將上下疊合之縫製布料 W供給箭頭Υ所示之縫製進行方向（因眾所周知，省略圖 不)），並且在上述針板2之上部，設置壓腳7(用來將被縫 製布料W按壓於該針板2上面），透過壓腳臂8能上下動 ，構成：邊以進給齒將縫製布料W供給於縫製進行方向γ ’邊以縫針與省略圖示之線鉤之協調動作來進行端緣包縫 〇 比上述針板2之落針部6更靠縫製進行方向γ之位置 ’設置切刀機構9(用來將順沿交叉板1及針板2之上面向 洛針部6供給於縫製進行方向γ的縫製布料w之端緣We 切斷整齊）。該切刀機構9，係構成：具備平板狀之上切刀 9A與帶板狀之下切刀9B，藉由將該切刀機構9向與縫製 進行方向Y正父之XI — X2方向移動，能調整切齊位置， 10 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公爱) — - --------------裝—— (請先閱讀背面之注意事項再填寫本頁) 訂- 線- A7 550320 五、發明說明) 即，包縫寬度。該切刀機構9之具體構成及包縫寬度之調 整構造係如下所述。 即，如圖5所明示，在上切刀軸臂11(固定於連動在 拷克車主軸(因眾所周知，省略圖示)之上切刀軸10且會搖 動)透過固定螺絲13及長孔14向箭頭XI — X2方向移動 固定自如地安裝L字形狀之上切刀夾持具12，以按壓該上 切刀夾持具12之側面而透過螺絲15及長孔16能向上下調 整位置之狀態，安裝平板狀之上切刀9A。 另一方面，在配置且固定於交叉板1之下部之下切刀 座裝配具17，以透過內藏於該裝配具17之彈簧18在對縫 製進行方向Y正交之XI — X2方向向上切刀9A側加上彈 壓力量的狀態，支撐下切刀座19，在該下切刀座19透過 下切刀壓件20及固定螺絲21固定保持帶板狀之下切刀9B ，並且設置固定螺絲22(用來將下切刀座19抵抗彈簧18 之彈壓力量而能鎖緊固定於下切刀座裝配具17)。又，圖5 中之23係下切刀座19之防旋轉構件，透過固定螺絲24固 定於下切刀座裝配具17。 如上述構成之切刀機構9，係構成：藉由鬆弛固定螺 絲13，將上切刀夾持具12及上切刀9A順沿長孔14，向 與縫製進行方向Y正交之XI — X2方向移動必要量且固定 ’並且鬆弛固定螺絲22，將下切刀座19及下切刀9B以彈 簧18之彈壓力量，或，抵抗彈簧18之彈壓力量，移動於 與上述同樣XI — X2方向，彈性緊接上下兩切刀9a、9B ’使包縫寬度能調整。 11 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐)' -------------裝--------訂---------線 <請先閱讀背面之注意事項再填寫本頁) A7 550320 五、發明說明（P ) 比如上述切刀機構9更靠縫製進行方向Y之位置之針 板2之上方及下方位置，亦如圖3及圖4所示，分別設置 反射式光電感測器25及26(用來藉由向上布料Wii及下布 料Wd分別投光之光線的反射光是否受光，來個別檢測上 布料Wii及下布料Wd之端緣部之有無）。上下之反射式光 電感測器25、26中，下側之光電感測器26，因上述切刀 機構9之下切刀座19等之切刀機構用構件存在而沒有足夠 之安裝空間，故使用光纖感測器。 上側之反射式光電感測器25，如圖1所示，係構成： 以透過形成於感測器裝設臂板27之長孔28及嵌合於該長 孔之螺絲29向與縫製進行方向γ正交之XI — X2方向移 動固定自如之狀態，安裝於機框3，配合上述切刀機構9 之切齊位置(包縫寬度)之調整使感測位置能調整。 另一方面’以光纖感測器所組成之下側之光電感測器 26，如圖2〜圖4所示，係構成：透過光纖支撐件30及光 纖壓件31固定支撐於切刀機構9之下切刀座19，伴隨爲 上述包縫寬度之調整而移動下切刀座19於XI — X2方向 ，使與下切刀9B及下切刀座19 一體能調整感測位置。又 ，在下側之光電感測器26之檢測端26a所面臨之針板2部 分’形成長孔狀之導引槽32(用來即使是爲調整包縫寬度 使光電感測器26與下切刀座19 一體移動於XI 一 χ2方向 之任一位置之情形’對下布料Wd之既定之測感機能能保 持）。 又’在上布料Wu及下布料W(J之間，介在板狀之縫 12 本紙張尺度適用中國國家標準（CNS)A4規格（21〇 X 297 -- -----I--1 —---- I I I----訂--------•線 (請先閱讀背面之注意事項再填寫本頁) A7 550320 五、發明說明（11) 製布料導引構件33(用來導引上，下布料Wu、Wd移動於 縫製進行方向Y)，形成：在該布料導引構件33之上下面 分別黏著回歸反射帶34、35而將來自上下之光電感測器 25、26之投光光線向上方及下方反射的反射面(反射部）。 該具有上下反射帶34、35之導引構件33，係固定於 透過裝設板36及底座37而固定支撐在機框3之伸縮(進退 )壓缸38之動桿38a前端部，藉由壓缸38之伸縮動作，構 成：其頂端，在延出於針板2上之縫製布料導引作用位置 與從針板2離開之非導引作用位置之間，能變更位置自如 〇 圖6，係表示含有上述上下之反射式光電感測器25、 26的漏針檢測裝置之電路構成的方塊圖，上下之各光電感 測器25、26所產生之檢測訊號SI、S2經放大器40、41 放大後，輸入於控制部· 42。在該控制部42，除檢測訊號 SI、S2外，分別輸入來自旋轉檢測器44(係安裝於拷克車 Μ之例如主軸(省略圖示），用來檢測旋轉之有無)之檢測訊 號S3，及來自容許漏針設定器43(用來將順沿縫製進行方 向Υ取一疋長度軸圍之谷g午漏針量的運針數，預先由作業 者輸入數値)之容許漏針量(運針數)設定訊號S4，該控制部 42，將相當於上下兩光電感測器25、26所產生之檢測訊號 SI、S2中之任何一方之訊號的輸入繼續時間之運針數，與 設定訊號S4之容許運針數作比較，當檢測運針數超過容許 運針數時，判定有漏針而輸出訊號S5。 在上述控制部42，連接漏針通知機構45(以燈，蜂鳴 13 度適用中國國家標準（CNS)A4規格（210 X 29Ϋ公釐）> 一 — — 111! — — —--· I I I I---訂------I I (請先閱讀背面之注意事項再填寫本頁) A7 55032ο ____B7___ 五、發明說明（/ L) 器或顯示畫面中至少一項所構成），構成：接受來自上述控 制部42之輸出訊號S5，燈就發亮，或蜂鳴器就響，或， 顯示文字等於畫面，來向作業者通知漏針已發生。又，上 述容許漏針量係以運針數之設定任意可變，然替代該運針 數，亦可使用計時器(從上下兩光電感測器25、26所產生 之檢測訊號SI、S2中之任何一方輸入於控制部42的時刻 _始動作），藉由該計時器之動作限時時間之設定，使容許 漏針量爲可變。 其次，就使用具備如上述構成之漏針檢測裝置的拷克 車Μ，例如進行T恤之裝袖縫製等時的漏針檢測動作，參 煦圖7之流程圖及圖8(A)、（Β)之作用圖簡單說明。 如Τ恤之袖用布料與身片用布料等，上布料Wu及下 布料Wd上下疊合的縫製布料W，係以前•後進給齒順沿 交叉板1及針板2之上面向縫製進行方向Y供給，在靠近 落針部6之位置以切刀機構9將其端緣We切齊後，移送 至落針部6而進行縫針與省略圖示之線鉤之協調動作使端 緣包縫。 如上述端緣包縫縫製時，貼上下反射帶34、35之導引 構件33透過壓缸38定位於將其頂端延出在針板2上之縫 製布料導引作用位置，即使縫製布料W係薄件，將上，下 布料Wu、Wd順沿導引構件33以不發生鬆弛之方式移動 導引。而且，在比切刀機構9更靠近作業者這邊位置，從 上下兩光電感測器25、26向縫製布料W之上布料Wu及 下布料Wd的端緣部投光脈動狀之光線，藉由是否受光其 14 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） ---— — — — — — —------ (請先Μ讀背面之注意事項再填寫本頁) 訂-· -線- A7 550320 ~-------- 五、發明說明（/)) 反射光，來檢測上下布料Wu、Wd的端緣部之有無(步驟 Sll、S12)。 在此，上布料Wu及下布料wd的端緣部，如圖8(A) ，一起在比投光光線突出右側之狀態，上下之光電感測器 25、26就不接受反射光，因從光電感測器25、26向控制 部42輸入有布料端緣部之檢測訊號S1、S2，故在輸入有 布料端緣部之檢測訊號SI、S2的控制部42，藉由檢測訊 號SI、S2之訊號處理判定爲無漏針(步驟S13)，不移動至 下一步驟’仍然繼續進行既定之端緣包縫縫製。 另一方面，如圖8(B)，上布料Wu及下布料Wd中， 任何一方之端緣部，例如上布料Wu之端緣部在比投光光 線突出左側之狀態，來自上側之光電感測器25之投光光線 就從黏著於導引構件33之上面的反射帶4向上方反射，上 側之光電感測器25受光其反射光，從該上側之光電感測器 25向控制部42輸入無布料端緣部之檢測訊號S1，又，從 下側之光電感測器26向控制部42輸入有布料端緣部之檢 測訊號S2，藉由檢測訊號SI、S2之訊號處理判定爲有漏 針(步驟S13)。 在上述控制部42，已由作業者輸入運針數設定訊號 S4(當作順沿縫製進行方向Y長度之容許漏針量，預先輸 入數値於容許漏針設定器43)，該設定訊號S4之容許運針 數Ml與檢測運針數M2作比較(步驟S14)，當檢測運針數 M2比容許運針數Ml小時，不輸出訊號S5，當檢測運針 數M2超過容許運針數Ml時，判定爲漏針發生而從控制 15 ΐ紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） -------------裝--------訂---------線 (請先閱讀背面之注意事項再填寫本頁) A7 550320 五、發明說明（I十） 部42輸出訊號S5(步驟S15)。藉由將來自該控制部42之 輸出訊號S5，輸入於漏針通知機構45，燈就發亮，或蜂鳴 器就響，或，顯示文字等於畫面，來向作業者通知漏針之 發生。 如上述，藉由分別設置於針板2之上方及下方位置的 反射式光電感測器25、26，個別檢測上下疊合之上布料 Wu及下布料Wd的端緣部之有無，以兩檢測訊號之訊號處 理來判定縫製布料W有無漏針，藉由根據其判定結果使通 知機構45動作，在要縫製縫製布料w之厚度(厚薄)或布 料固有之光透過特性相異之任何種類的布料之情形，亦不 需要事前進行光電感測器25、26之感度調整，只要上布料 Wu及下布料Wd之任何一方，其端緣部發生從既定之縫製 位置脫離之漏針，就能確實且正確地檢測。 又，如本實施形態，藉由將下側之光電感測器26被支 撐於切刀機構9之下切刀座19，伴隨爲切齊位置之調整而 移動下切刀座19，能將下側之光電感測器26與下切刀座 19 一體向XI — X2方向調整位置，能使爲包縫寬度調整 當然要進行之下切刀座19的移動量與對應包縫寬度調整所 必要之下側之光電感測器26的位置調整量完全一致’在包 縫寬度之調整後，不需要另外調整下側之光電感測器26的 位置，確保著既定之漏針檢測機能而能容易且迅速進行包 縫寬度調整。在此，上側之光電感測器25，藉由將來自伴 隨下切刀座19之移動一體位置調整的下側之光電感測器 26的投光光線爲照準’透過形成於感測器裝設臂板27之 16 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） -----II-----^裝— — —訂---------線 (請先閱讀背面之注意事項再填寫本頁) A7 550320 _B7___ 五、發明說明（I Y) 長孔28及嵌合於該長孔之螺絲29向與縫製進行方向Υ正 交之XI — Χ2方向移動且固定，來調整感測位置，能容易 且正確地調整於包縫寬度調整後之既定之檢測位置。 又，藉由將導引構件33構成：如上述在縫製布料導引 作用位置與從針板2離開之非導引作用位置之間，能變更 位置自如，即使縫製對象物爲筒狀縫製物之情形，其筒狀 縫製物之縫製已進行而其縫製開始端部來至落針部6前面 時，藉由透過壓缸38將導引構件33變更位置至非導引作 用位置(退避），不使縫製開始端部掛住導引構件33，能確 實縫製至縫製結束端部，並且，不使縫製後之筒狀縫製物 受導引構件33之阻礙而能從縫製處容易取出。 又，藉由在上下之光電感測器25、26，使用：分別具 有偏光濾波器(省略圖示）於其投光•受光元件之前面，在 投光側通過偏光濾波器僅投光橫方向（或縱方向）之波之光 線，且，在受光側通過偏光濾波器僅受光縱方向(或橫方向 )之波之反射光線的回歸反射型之光電感測器，並且在回歸 反射帶34、35(用來將來自上下之光電感測器25、26之投 光光線向上方及下方反射），使用：具有僅將所投光之橫方 向（或縱方向）之波之光線，偏光於所有方向之波之光線而 反射之機能的回歸反射帶，即使在投光位置存在有光澤之 物體或部位，或縫製布料W本身爲光反射性強者，能明確 區分來自這些之反射光(外亂光)與來自反射帶34、35之反 射光，藉此，上下光電感測器25、26僅正確檢測上下布料 Wu、Wd的端緣部之有無，沒有誤檢測，誤檢測動作，能 17 本紙張尺度適用中國國家標準（CNS)A4規格（210x 297公f )~~一 "~ -----I-------------II 訂-----I---線 (請先閱讀背面之注意事項再填寫本頁) A7 550320 B7___ 五、發明說明（/i) 顯著提高既定之漏針檢測精度。 又，本發明之反射部，較佳者爲由具有上述之偏光機 能之回歸反射帶34、35所形成，然亦可使用未具那樣偏光 機能之反射帶，或，亦可將導引構件33之上下面作鏡面加 工來形成反射面。 又’本發明，基本上係只要藉由作業者認識有漏針來 防止縫製不良品之發生即可，雖就設置燈或蜂鳴器，顯示 畫面等之通知機構來說明，但除此之外，亦可附加伴隨漏 針檢測便縫紉機Μ自動停止之構成。 (請先閱讀背面之注意事項再填寫本頁) 裝 訂· * --線* 18 本紙張尺度適用中國^家標準（CNS)A4規格（21〇 χ 297公楚）A7 550320 V. Description of the Invention (f) [Technical Field] The present invention relates to the end of at least one of the two pieces of sewn fabric that are used to seal the top and bottom of the fabric when it is mainly sewn with a copy truck. The sewing machine's missing needle detection device is used to detect whether the edge part is detached from a predetermined sewing position and detect it optically to prevent the occurrence of defective products. [Know-how] When using an overlock car to sew over the edge of overlaid sewing fabric, especially because the bottom fabric is difficult to watch and the position correction during sewing is very difficult, the end edge is orthogonal to The fabric is shifted in the width direction of the sewing progress direction and detached from the predetermined sewing position (sewing trace), so-called missing stitches are likely to occur. The leak described above is a fatal disadvantage for sewing products. An apparatus for optically detecting the missing needles as described above to prevent the occurrence of defective sewing products is known, for example, disclosed in Shi Sho 59-25349 and the like. It is known to use a light-transmissive type photoinductor to detect a leak. needle. The conventional missing pin detection device disclosed in the aforementioned publications and the like uses a light-transmitting type photoinductor (comprised of a light projector that emits light to the sewing fabric and a light receiver that responds to light emitted by the projector and transmits light through the sewing fabric) The missing stitches are detected by detecting the number of overlapping pieces of the sewing fabric, that is, detecting the increase or decrease in the amount of transmitted light that changes whether the upper fabric and the lower fabric overlap. However, in the case of a conventional missing-pin detection device using a light-transmitting type photoinductor, the presence or absence of missing pins is detected by increasing or decreasing the amount of transmitted light, and the type of sewing fabric that differs in thickness or light transmission characteristics changes. When you need 3 ------ II -------- I ---- Order -------- I (Please read the precautions on the back before filling this page) This paper size Applicable to China National Standard (CNS) A4 Regulations (210 X 297 mm) — 'A7 550320 V. Description of the Invention (V) Perform the troublesome and time-consuming tasks such as adjusting (correcting) the sensitivity of the optical sensor. Therefore, the missing needle detection device of a sewing machine used for sewing a small amount of a variety of fabrics has a problem of lack of practicality. [Summary of the invention] The present invention is made in light of the above-mentioned facts, and its purpose is to provide: Even if any kind of fabrics with different thickness or light transmittance are to be sewn, no troublesome sensitivity adjustment work is required, and Missing stitch detection device for sewing machines that accurately detects missing stitches. In order to achieve the above purpose, the missing needle detection device related to the invention described in the first item of the patent application is installed near the needle drop portion of the needle plate, and the end edge portion of the sewing fabric superimposed on top is optically detected. Whether it is detached from a predetermined sewing position is characterized by being provided with: a reflective photodetector provided above and below the needle plate, and individually detecting the presence or absence of an end edge portion of the upper fabric and an end edge portion of the lower fabric; The reflecting part is formed above and below the sewing fabric guide member; used to reflect the light projected from the upper and lower photosensors upward and downward respectively; the sewing fabric guide member is interposed between the upper and lower fabrics, And the position can be changed freely between the guided action position of the sewing fabric and the non-guided action position separated from the needle plate; it is used to guide the upper and lower fabrics to move in the sewing direction; and the detection mechanism handles the upper and lower reflective photo inductors The two detection signals obtained by the tester are used to determine the presence or absence of missing stitches in the sewing fabric, and act upon receiving the determination result. 4 This paper size applies to Chinese National Standard (CNS) A4 (210 X 297). &Quot; ----- — — — —----- · II (Please read the precautions on the back before filling this page) Order:-line · 550320 B7 V. Description of the invention ($) According to the invention described in item 1 of the above-mentioned application patent scope, the presence of the upper edge of the upper fabric and the lower fabric are individually detected. The signal processing is used to determine the presence of missing stitches in the sewing fabric, and the detection mechanism is actuated based on the result of the determination. Therefore, it exhibits the following effects: Any kind of fabric with a different thickness (thickness) or inherent light transmittance of the fabric When it is a sewing object, it is not necessary to perform the sensitivity g of the photo sensor before the whole process, and the occurrence of the missing needle that detaches the edge portion of either the upper fabric or the lower fabric from the predetermined sewing position can be sure. And detect it correctly. Furthermore, in the "missing needle detection device of the sewing machine having the above-mentioned configuration, the reflecting portion that reflects the light projected from the upper and lower photoinductors upward and downward respectively" as described in the first item of the scope of patent application, The structure is formed above and below the sewing fabric guide member (between the upper and lower fabrics and guides the upper and lower fabrics to move in the sewing direction). Even for thin fabrics, the upper and lower fabrics can be guided along the guide member so as not to occur. The relaxation mode moves and guides to make the reflection effect of the upward and downward projection light rays definite and improve the detection performance of the presence or absence of the cloth edge edges of the upper and lower photosensors. Also, as described above, the missing needle detection device of a sewing machine provided with a guide member with an upper and lower reflecting surface, as described in item 1 of the scope of patent application, by making the guide member at the position where the sewing fabric is guided and separated from the needle plate The structure of changing the position between the non-guided action positions freely, even if the sewing object is a cylindrical sewing object, does not make the guide member a predetermined obstacle to sewing, or an obstacle to take out the sewing object after sewing. . That is, when the sewing of the tubular sewing product is already in progress and the end of the sewing start comes to the front of the needle drop portion, the guide member is changed {^ set (retracted) to a non-guided action position, and the sewing is not opened 5 times. Paper size applies to China National Standard (CNS) A4 (210 X 297 public love) ---- --------------------- Order ----- ---- Thread (please read the precautions on the back before filling this page) 550320 A7 ______ V. Description of the invention (ι |) The leading end can be hung by the guide member, and it can be surely sewn to the end of sewing, and the sewing The subsequent cylindrical sewing object can be taken out from the sewing place without being hindered by the guide member, so that the missing needle detection device can also be effectively applied to the cylindrical sewing object. The missing needle detection device of the sewing machine configured as described above, as described in item 2 of the scope of patent application, preferably, the above-mentioned reflection type photoelectric sensor is a cutter mechanism provided at the edge of the sewing fabric. It depends on the position in front of the sewing progress direction, along with the cutter mechanism moving in the orthogonal direction of the sewing progress direction, and with the adjustment of the cutting position, the position of the upper and lower reflective photosensors can be adjusted. According to the invention described in item 2 of the scope of the patent application structured as above, in addition to the above effects, when the width of the overlock is adjusted by the movement of the cutter mechanism, the position of the upper and lower photosensors can be adjusted along with this. At the predetermined detection position corresponding to the cutting position of the cutter mechanism, the predetermined missing needle detection function can be reliably maintained even if the overlock width is adjusted. In particular, as described in item 3 of the scope of the patent application, as the position adjustment structure of the photo sensor, the lower photo sensor is supported by the cutter base under the cutter mechanism, and the alignment position is adjusted along with it. And moving the lower cutter holder, so that the lower photoelectric sensor can be integrated with the lower cutter holder to adjust the position, of course, in order to adjust the overlock width, of course, the amount of movement of the lower cutter holder and the position of the lower optical sensor can be adjusted. The amount of adjustment is completely the same. After the adjustment of the overlock width, the trouble of adjusting the position of the photodetector on the lower side becomes unnecessary, which can be easily and quickly performed while ensuring the predetermined missing pin detection function. Overlock seam width adjustment. In addition, the upper photo sensor is adjusted by adjusting the 6 paper sizes from the lower photo sensor with the movement of the lower knife holder as a whole. The Chinese paper standard (CNS) A4 (21〇X 297) (Li) -------- II ----------- Order --------- line (Please read the precautions on the back before filling this page) A7 550320 V. Description of the invention (^) The projected light is adjusted to the position according to the aim, and the predetermined detection position after the overlock width adjustment can be adjusted easily and correctly. In addition, the missing pin detection device of the sewing machine having the above-mentioned configuration, "at least the lower one of the upper and lower reflection-type photo-sensors" uses a fiber-optic sensor as described in item 4 of the scope of patent application. A structure in which the optical fiber sensor is fixedly supported by the cutter base under the cutter mechanism. 'The lower optical sensor is installed in a cutter mechanism such as a lower cutter base to ensure a predetermined sensing function. Places where the installation space is not sufficient due to the presence of components. Furthermore, the reflection part of the missing stitch detection device of the sewing machine configured as described above is the simplest to form a retro-reflective tape as described in item 5 of the scope of patent application, and can obtain a reliable detection function. However, in addition to this, For example, the upper and lower surfaces of the guide member can be mirror-finished to form a reflective surface. In addition, as described in item 6 of the scope of the patent application, the upper and lower photoinductors are retro-reflective photoinductors, each having a polarizing filter in front of its light-emitting and light-receiving elements and on the light-emitting side. A polarizing filter is used to emit only rays of horizontal or vertical waves, and a polarizing filter is used on the light-receiving side to receive only reflected rays of longitudinal or horizontal waves, and the reflecting surface of the reflecting portion ( Reflecting the projected light rays from the upper and lower photosensors upwards and downwards) uses a retro-reflective tape, which has only the rays of the horizontal or vertical waves of the projected light polarized into the rays of waves of all directions. The function of reflection, even if there are shiny objects or parts at the light-emitting position, or the cloth itself is highly reflective, can clearly distinguish the reflected light (external disturbance light) from these and the reflected light from the reflection band, thereby, Up and down 7 paper sizes are applicable to China National Standard (CNS) A4 specifications (210 X 297 mm) I --------------------- Order ------ -(Please read the notes on the back before filling this page) 55032 0 A7 B7 V. Description of the invention (The photo sensor only correctly detects the presence or absence of the end edges of the upper and lower fabrics. There is no false detection and false detection action, which can significantly improve the accuracy of the established missing needle detection. Other objects and effects of the present invention, The embodiment to be described below will be more clear. [Simplified description of the drawing] Fig. 1 is a schematic perspective view of a main part of a copy truck equipped with the missing needle detection device of the present invention. Fig. 2 is a view of the above-mentioned sewing machine. Top view of the main part. Fig. 3 is a front view of the main part of the sewing machine. Fig. 4 is a right side view of the main part of the sewing machine. Fig. 5 is an exploded view of the main part showing the detailed structure of the cutter mechanism of the sewing machine. A perspective view. Figure 6 'is a block diagram of the circuit configuration of the double measuring device without the missing pin of the upper and lower reflective photodetector 1. Fig. 7 is a flowchart illustrating the missing pin detection operation when overlocking. Figure 8 (A), (B) are schematic side views explaining the detection status of the upper and lower fabric edges at the time of overlocking. [Symbols] 1 2 3 6 Cross-needle needle board machine frame needle drop clothing paper size Applicable China Home Standard (CNS) A4 Specification (210 X 297 mm) -------------- Shang --- (Please read the precautions on the back before filling this page) · -Line-550320 A7 B7 V. Description of the invention (1) 9 9A 9B 17 19 25 26 33 34, 35 40, 41 42 43 44 45 Μ Ml M2 SI, S2, S3 54 55 W Wu Wd We Cutter mechanism Upper cutter Lower cutter Lower cutter Knife holder assembly tool Lower reflective photo sensor on the upper side of the knife holder Reflective photo sensor guide member on the lower side Retro-reflection tape Amplifier control unit Allowed missing needle setting device Rotary detector Missing needle notification mechanism Sewing machine allowable stitch detection Needle number detection signal setting signal output signal Sewing fabric Upper fabric Lower fabric end edge --------- I ---- · II (Please read the precautions on the back before filling this page) • Thread 'This paper The dimensions are applicable to Chinese National Standard (CNS) A4 specifications (210 X 297 mm) A7 550320 V. Description of invention (t) Y sewing direction [preferred embodiment of invention] The following describes the scope of patent application according to the first item Embodiments of the present invention as described in the ninth aspect. Fig. 1 is a schematic perspective view of a main part of a copying machine (sewing machine) M provided with a missing needle detection device according to the present invention, and Fig. 2 is a plan view of a main part of the sewing machine M described above. The needle plate 2 is fixed to the cross plate 1 of the copy truck M with its upper surface on the same surface as the cross plate 1. On the lower part of the throat plate 2, the needle drop part 6 is held in front of and behind the needle (the needle fixing member is fitted to the lower end portion (not shown) of the needle bar 4 supported by the needle bar 4 of the machine frame 3 for reciprocating up and down movement). Position, equipped with front and rear feed teeth (used to feed the superimposed sewing fabric W to the sewing progress direction shown by arrow Υ (because it is well known, the figure is not shown)), and above the needle plate 2, A presser foot 7 (for pressing the material W to be sewn on the needle plate 2) is provided. The presser foot arm 8 can move up and down, and is configured to feed the sewing material W to the sewing progress direction γ 'while feeding teeth. Coordinated action of the needle and a thread hook (not shown) to perform overlocking at the edge. The cutter mechanism 9 is provided at the position γ more than the needle drop portion 6 of the needle plate 2 described above. The edge We of the sewing fabric w supplied on the upper surface of the needle plate 1 and the needle plate 2 in the sewing progress direction γ is cut neatly). The cutter mechanism 9 is configured to include a flat upper cutter 9A and a belt-shaped lower cutter 9B. The cutter mechanism 9 can be moved in the direction XI-X2 of the positive Y of the sewing direction by sewing. Adjust the cut position, 10 paper sizes are applicable to China National Standard (CNS) A4 specifications (210 X 297 public love) —--------------- install—— (Please read the Please fill in this page again for instructions) Order-thread-A7 550320 V. Description of the invention) That is, overlock width. The specific structure of the cutter mechanism 9 and the adjustment structure of the overlock width are as follows. That is, as clearly shown in FIG. 5, the upper cutter shaft arm 11 (fixed to the cutter shaft 10 which is linked to the main shaft of the lock truck (because it is well known and omitted from illustration) and swings) passes through the fixing screw 13 and the long hole 14 Move in the direction of arrows XI-X2 to install the L-shaped upper cutter holder 12 in a fixed manner, press the side of the upper cutter holder 12 and adjust the position up and down through the screws 15 and the long holes 16 , Install the flat upper cutter 9A. On the other hand, the cutter holder assembly tool 17 is arranged and fixed below the lower part of the cross plate 1 so as to cut upward through the spring 18 built in the assembly tool 17 in the XI-X2 direction orthogonal to the sewing direction Y. In the state where the elastic pressure is added on the 9A side, the lower cutter holder 19 is supported, and the lower cutter holder 19 is fixed to hold the plate-shaped lower cutter 9B through the lower cutter holder 20 and the fixing screw 21, and a fixing screw 22 (for The lower cutter holder 19 can be locked and fixed to the lower cutter holder assembly 17 against the amount of spring pressure of the spring 18. Further, 23 in FIG. 5 is an anti-rotation member of the lower cutter holder 19, and is fixed to the lower cutter holder assembly 17 by a fixing screw 24. The cutter mechanism 9 constituted as described above is constituted by slackening the fixing screw 13 and passing the upper cutter holder 12 and the upper cutter 9A along the long hole 14 to XI-X2 orthogonal to the sewing direction Y. Move the necessary amount in the direction and fix it, and loosen the set screw 22, and move the lower cutter base 19 and the lower cutter 9B with the spring pressure of the spring 18, or resist the spring pressure of the spring 18, and move in the same direction XI-X2 as above, elastically tight. Connect the upper and lower cutters 9a, 9B 'to make the overlock width adjustable. 11 This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) '------------- Installation -------- Order ------ --- Thread <Please read the precautions on the back before filling this page) A7 550320 V. Description of the invention (P) For example, the above cutter mechanism 9 is more above and below the needle plate 2 at the position Y in the sewing direction As shown in Fig. 3 and Fig. 4, reflective photo-sensors 25 and 26 are provided respectively (for detecting whether the reflected light of the light projected by the upper cloth Wii and the lower cloth Wd is received, respectively, to individually detect the upper cloth The presence or absence of the edges of Wii and the lower cloth Wd). Among the upper and lower reflection-type photodetectors 25 and 26, the photodetector 26 on the lower side has a sufficient space for installation of the cutter mechanism members such as the cutter holder 19 below the cutter mechanism 9 and the like, and therefore is used. Fiber optic sensor. As shown in FIG. 1, the upper reflection-type photodetector 25 is configured to pass through the long hole 28 formed in the sensor mounting arm plate 27 and the screw 29 fitted in the long hole toward the sewing direction. Orthogonal XI-X2 direction can be moved and fixed freely, and it is installed on the machine frame 3, and the sensing position can be adjusted with the adjustment of the cutting position (overlock width) of the cutter mechanism 9 mentioned above. On the other hand, as shown in FIG. 2 to FIG. 4, the optical sensor 26 under the optical fiber sensor is composed of: fixedly supported by the cutter mechanism 9 through the optical fiber support member 30 and the optical fiber pressing member 31. The lower cutter holder 19 moves the lower cutter holder 19 in the XI-X2 direction along with the adjustment of the overlock width, so that the sensing position can be adjusted integrally with the lower cutter 9B and the lower cutter holder 19. In addition, a long hole-shaped guide groove 32 is formed in the needle plate 2 portion 'facing the detection end 26a of the lower photoelectric sensor 26 (for the purpose of adjusting the width of the overseal to make the optical sensor 26 and the lower cutter In the case where the seat 19 is integrally moved to any position in the XI-χ2 direction, 'the predetermined sensing function of the lower cloth Wd can be maintained). Also 'between the upper cloth Wu and the lower cloth W (J, interposed between the plate-like seams 12 paper standards applicable to Chinese National Standard (CNS) A4 specifications (21〇X 297------ I--1 — ---- II I ---- Order -------- • Thread (please read the precautions on the back before filling this page) A7 550320 V. Description of the invention (11) Fabric guide 33 ( It is used to guide the upper and lower cloths Wu, Wd to move in the sewing direction Y), forming: the retro-reflective tapes 34, 35 are adhered to the upper and lower cloth guide members 33, respectively, and the upper and lower photosensors 25, 25 The reflection surface (reflection part) of the 26th projection light reflected upward and downward. The guide member 33 having the upper and lower reflection bands 34 and 35 is fixed to the chassis 3 through the mounting plate 36 and the base 37. The front end of the movable rod 38a of the telescopic (advancing and retracting) pressure cylinder 38 is configured by the telescopic action of the pressure cylinder 38: the top end of the movable rod 38a extends from the needle plate 2 at the leading position of the sewing fabric and moves away from the needle plate 2. The position can be changed freely between non-guided positions. Figure 6 shows the missing pin detection device including the above-mentioned upper and lower reflective photodetectors 25 and 26. A block diagram of the circuit configuration. The detection signals SI and S2 generated by the upper and lower photoinductor sensors 25 and 26 are amplified by amplifiers 40 and 41 and input to the control unit 42. In this control unit 42, the detection signals SI, In addition to S2, the detection signals S3 from the rotation detector 44 (such as the main shaft (not shown) installed on the copy truck M, for detecting the presence or absence of rotation), and the allowable missing needle setter 43 (for The direction of sewing along the direction of the sewing process is to take the number of stitches in the valley g of the length of the shaft around the shaft, and the operator enters the number in advance.) The allowable amount of stitches (number of stitches) is set to signal S4. The number of stitches corresponding to the input continuation time of any one of the detection signals SI and S2 generated by the upper and lower photosensors 25 and 26 is compared with the allowable number of stitches of the set signal S4. When the number of stitches is moved, it is determined that there is a missing stitch and the signal S5 is output. The above-mentioned control section 42 is connected to the missing stitch notification mechanism 45 (with a light and a 13-degree beep, the Chinese National Standard (CNS) A4 specification (210 X 29 mm) is applied) ; One — — 111! — — —- -· III I --- Order ------ II (Please read the precautions on the back before filling this page) A7 55032ο ____B7___ V. Description of Invention (/ L) At least one of the device or display screen) Composition: Upon receiving the output signal S5 from the control unit 42 above, the lamp will light up, or the buzzer will sound, or the text will be displayed on the screen to notify the operator that a missing needle has occurred. In addition, the above-mentioned allowable missing needle volume is The setting of the number of stitches can be arbitrarily changed, but instead of the number of stitches, a timer (the time when any one of the detection signals SI and S2 generated by the upper and lower photosensors 25 and 26 is input to the control section 42) _Start action), by setting the action time limit of the timer, the allowable missing stitch amount can be changed. Next, using a copy truck M equipped with the missing needle detection device configured as described above, for example, when performing a missed needle detection operation when sewing a sleeve of a T-shirt, etc., refer to the flowchart in FIG. 7 and FIG. 8 (A), ( The function diagram of B) is briefly explained. For example, the cloth for sleeves and body for T-shirts, the upper cloth Wu and the lower cloth Wd are superimposed on top of each other, which are the front and rear feed teeth along the cross plate 1 and the needle plate 2 facing the sewing direction. Y supply, after cutting the end edge We of the cutter mechanism 9 near the needle drop portion 6, it is transferred to the needle drop portion 6 to perform a coordinated operation of the needle and a thread hook (not shown) to overlock the edge. As described above, when the edge edge package is sewn, the guide member 33 attached to the upper and lower reflection tapes 34 and 35 is positioned through the pressure cylinder 38 to the position of the sewing fabric guide where the top end extends out of the needle plate 2. For thin pieces, move the upper and lower cloths Wu, Wd along the guide member 33 in a manner that does not cause slackening. Further, at a position closer to the operator than the cutter mechanism 9, the upper and lower photosensors 25 and 26 project pulsating rays of light toward the edges of the upper cloth Wu and the lower cloth Wd of the sewing cloth W. 14 paper sizes are subject to Chinese National Standard (CNS) A4 specifications (210 X 297 mm) whether or not received by light. ---------------- (Please read the precautions on the back first (Fill in this page) Order-· -Line-A7 550320 ~ -------- V. Description of the invention (/)) Reflect the light to detect the presence or absence of the edges of the upper and lower cloths Wu, Wd (steps S11, S12) ). Here, the edges of the upper cloth Wu and the lower cloth wd, as shown in FIG. 8 (A), are in a state protruding more to the right than the projected light, and the upper and lower optical sensors 25 and 26 do not receive the reflected light. The photodetectors 25 and 26 input the detection signals S1 and S2 of the cloth edge portion to the control portion 42. Therefore, the control portion 42 having the detection signals SI and S2 of the cloth edge portion input the detection signals SI and S2 The signal processing judges that there is no missing stitch (step S13), and it does not move to the next step, and the predetermined end edge package sewing is continued. On the other hand, as shown in FIG. 8 (B), the upper edge of the upper cloth Wu and the lower edge of the cloth Wd, for example, the upper edge of the upper edge of the upper edge of the upper edge of the upper edge of the upper edge of the upper edge of the upper edge of the upper edge of the upper edge. The light projected from the detector 25 is reflected upward from the reflection band 4 adhered to the upper surface of the guide member 33. The upper photodetector 25 receives the reflected light, and the light from the upper photodetector 25 to the control section 42. The detection signal S1 without the edge of the cloth is input, and the detection signal S2 with the edge of the cloth is input to the control unit 42 from the lower optical sensor 26, and it is determined as having the signal processing of the detection signals SI and S2. Missing stitches (step S13). In the above-mentioned control section 42, the operator has input the number of stitches setting signal S4 (as the allowable amount of missing stitches in the length Y along the sewing direction, and input the number in advance in the allowable missing stitch setter 43). The allowable number of stitches M1 is compared with the detected number of stitches M2 (step S14). When the detected number of stitches M2 is smaller than the allowable number of stitches M1, no signal S5 is output. When the detected number of stitches M2 exceeds the allowable number of stitches M1, it is determined that a missing stitch has occurred. From the control of 15 ΐ paper size, the Chinese National Standard (CNS) A4 specification (210 X 297 mm) is applied ------------- installation -------- order ---- ----- line (please read the precautions on the back before filling this page) A7 550320 V. Description of Invention (I) The section 42 outputs signal S5 (step S15). By inputting the output signal S5 from the control unit 42 to the missing needle notification mechanism 45, the lamp lights up, or the buzzer sounds, or the displayed text is equal to the screen to notify the operator of the occurrence of the missing needle. As described above, the presence or absence of the edge edges of the upper cloth Wu and the lower cloth Wd are individually detected by the reflection-type photodetectors 25 and 26 respectively provided above and below the needle plate 2, and two detections are performed. The signal processing is performed to determine whether there is a missing stitch in the sewing fabric W, and the notification mechanism 45 is actuated based on the determination result, and any kind of fabric having a different thickness (thickness) of the sewing fabric w or a light transmission characteristic inherent to the fabric is sewn. In this case, it is not necessary to adjust the sensitivity of the photo sensor 25 and 26 in advance. As long as the upper edge of the upper cloth Wu and the lower cloth Wd, a missing needle detached from the predetermined sewing position can be confirmed and Detect correctly. Further, as in this embodiment, the lower photoreceptor 26 is supported by the cutter holder 19 below the cutter mechanism 9 and the lower cutter holder 19 is moved with the adjustment of the alignment position, so that the lower cutter holder 19 can be moved. The photo sensor 26 and the lower cutter holder 19 are integrated to adjust the position in the direction of XI-X2, so that the movement of the lower cutter holder 19 must be performed for the overlock width adjustment, of course, and the lower photoelectricity necessary for the corresponding overlock width adjustment. The position adjustment amount of the sensor 26 is completely the same. 'After the over-slot width is adjusted, there is no need to adjust the position of the lower photo-sensor 26, which ensures the over-stitching function easily and quickly. Width adjustment. Here, the upper photoinductor 25 is formed by collimating the light projected from the lower photoinductor 26 with the movement of the lower cutter holder 19 to the position of the sensor mounting arm. Plate 27-16 This paper size is applicable to China National Standard (CNS) A4 specification (210 X 297 mm) ----- II ----- ^ installation---order --------- line (Please read the precautions on the back before filling in this page) A7 550320 _B7___ V. Description of the invention (IY) The long hole 28 and the screw 29 fitted in the long hole move in the direction XI orthogonal to the sewing direction — X 2 It is fixed to adjust the sensing position, and it can be easily and accurately adjusted to the predetermined detection position after the overlock width adjustment. In addition, the guide member 33 is configured such that the position can be changed freely between the guide action position of the sewing fabric and the non-guide action position separated from the needle plate 2 as described above, even if the object to be sewn is a cylindrical sewing object. In some cases, when the sewing of the tubular sewing material has been performed and the end of the sewing start has come to the front of the needle drop portion 6, the guide member 33 is changed to the non-guided action position (retracted) by the pressure cylinder 38. Hanging the guide member 33 at the end of the sewing can surely sew to the end of the sewing, and it is easy to take out the sewn tubular material without being hindered by the guide member 33. In addition, the upper and lower photoinductors 25 and 26 are used: each has a polarizing filter (not shown) in front of the light-emitting and light-receiving elements, and the polarizing filter is used to emit light only in the horizontal direction on the light-emitting side. (Or vertical direction) light rays, and a polarizing filter on the light-receiving side receives only the light reflected by the vertical (or horizontal) direction of light. 35 (used to reflect the light from the upper and lower photosensors 25, 26 upwards and downwards), use: light with only the horizontal (or vertical) waves of the light projected, polarized to all The retro-reflective reflection function of the light from the direction of the wave, even if there is a shiny object or part at the light projection position, or the sewing fabric W itself is highly reflective, it can clearly distinguish the reflected light from these (external disturbance light) ) And the reflected light from the reflection bands 34 and 35, so that the upper and lower photosensors 25 and 26 can accurately detect the presence or absence of the edge portions of the upper and lower cloths Wu and Wd, and there is no misdetection, and the misdetection action can achieve 17 papers. Scale applicable National Standard (CNS) A4 specification (210x 297 male f) ~~ 一 " ~ ----- I ------------- II Order ----- I --- (Please read the precautions on the back before filling this page) A7 550320 B7___ 5. Description of the invention (/ i) Significantly improves the accuracy of the missing needle detection. In addition, the reflecting portion of the present invention is preferably formed of the retro-reflective reflection belts 34 and 35 having the above-mentioned polarizing function, but it is also possible to use a reflecting belt having no such polarizing function, or the guide member 33 may also be used. The upper and lower surfaces are mirror-finished to form a reflective surface. In addition, the present invention basically requires that the operator recognize that there are missing stitches to prevent the occurrence of defective sewing products. Although a notification mechanism such as a lamp, a buzzer, and a display screen is provided for explanation, other than that, It is also possible to add a structure in which the sewing machine M automatically stops with the missing needle detection. (Please read the notes on the back before filling in this page.) Binding · *-Thread * 18 This paper size is applicable to China Standard (CNS) A4 (21〇 χ 297)