輸送機帶輪沖壓成形工藝與模具設(shè)計（落料拉深復(fù)合模+反拉深模具）

輸送機帶輪沖壓成形工藝與模具設(shè)計（落料拉深復(fù)合模+反拉深模具）,輸送,機帶輪,沖壓,成形,工藝,模具設(shè)計,落料拉深,復(fù)合,反拉深,模具 輸送機帶輪沖壓成形工藝與模具設(shè)計導(dǎo)師：工藝分析一 沖壓件工藝分析1.沖壓件精度分析及確定 零件形狀尺寸如圖1.0-1所示，查公差與配合技術(shù)手冊/方昆凡北京：北京出版社續(xù)表1-2得該零件的精度等級為IT10級；查表1-2確定各尺寸的公差值，47對應(yīng)公差為+0.10mm，36對應(yīng)公差為+0.10mm，100對應(yīng)公差為-0.14mm。材料：08鋼 料厚：t=1mm 大批量生產(chǎn) 圖1.0-1工件圖2.2.2.2.沖沖沖沖壓壓件件件件結(jié)結(jié)構(gòu)分析構(gòu)分析構(gòu)分析構(gòu)分析此零件材料此零件材料為為0808鋼鋼，料厚，料厚為為1mm1mm，且零件，且零件為軸對為軸對稱旋稱旋轉(zhuǎn)轉(zhuǎn)體，沖裁性能體，沖裁性能較較好；好；h/dh/d較較小，拉深工小，拉深工藝藝性性較較好，因此初步分析好，因此初步分析該該零件的沖零件的沖壓壓基本工序有：落料、基本工序有：落料、正拉深、反拉深、沖孔、修正拉深、反拉深、沖孔、修邊邊三三三三 工工工工藝藝方案方案方案方案1.1.1.1.計計算毛坯尺寸算毛坯尺寸算毛坯尺寸算毛坯尺寸外外緣緣拉伸后得到?jīng)_拉伸后得到?jīng)_壓壓件如件如圖圖1.0-21.0-2所示所示 圖1.0-21.0-2外外緣拉深后的沖拉深后的沖壓件件 外緣拉深屬于帶凸緣圓筒不變薄拉深，雖然材料厚度有變化，但是平均值與毛坯原始厚度十分接近。因此，毛坯展開尺寸可根據(jù)毛坯面積等于拉深件面積的原則來確定。由于材料的各向異性以及拉深時金屬流動條件的差異，為了保證零件的尺寸，必須保留出修邊余量，在計算毛坯尺寸時必須計入修邊余量。df/d=100/89=1.12,根據(jù)df/d數(shù)值查沖壓成形工藝與模具設(shè)計（第二版）P137中表5-2得修邊余量為3.5mm，所以df修正為df=100+3.52=107（mm）（注：d為中徑）。（1）毛坯直徑由表5-3當rR時，毛坯直徑為：已知代入D159mm（2 2）是否使用）是否使用壓邊圈圈毛坯的相對厚度tD100=1159100=0.63，零件拉深系數(shù)m1=dD=90159=0.57，查沖壓成形工藝與模具設(shè)計（第二版）P144中表5-7可知，0.63小于1.5,0.57小于0.6故需采用壓邊圈。表表5-75-7采用采用/不采用不采用壓料裝置的判料裝置的判別條件條件（3 3）計算拉深次數(shù)算拉深次數(shù)按下列數(shù)據(jù)dfd=1.12，tD=11590.63，查實用沖壓模具設(shè)計手冊p91表3-36得首次拉深允許的最大相對高度為：h1d1=0.500.60。工件的相對高度hd2=33880.375，得出拉深次數(shù)n=1。（4 4）驗證拉深系數(shù)是否超出極限拉深系數(shù)是否超出極限查沖壓成形工藝與模具設(shè)計（第二版）表5-10得mt=0.53，所以m1mt，拉深系數(shù)符合要求。表表5-105-10有凸有凸圓筒件的首次拉伸系數(shù)筒件的首次拉伸系數(shù)2.2.落料工序落料工序落料工序需沖裁出直徑D=159mm的板料。3.正拉伸正拉伸由以上計算可知，正拉深為首次拉深，且可一次拉深成所需的形狀，拉深過程中需使用壓邊裝置，拉深后工件的形狀如圖1.0-3所示。圖1.0-31.0-3首次拉深件首次拉深件四四 確定排確定排樣裁板方案以及材料利用率裁板方案以及材料利用率計算算根據(jù)上述計算，毛坯直徑已經(jīng)確定，可以進行排樣設(shè)計。1.1.排排樣方式的確定方式的確定根據(jù)工件的結(jié)構(gòu)和材料利用率情況有三種排樣方式，即有廢料排樣、無廢料排樣和少廢料排樣。由于毛坯直徑比較大，采用少廢料排樣；考慮操作方便，排樣采用直排單排。2.2.搭搭邊值確定確定查沖壓成形工藝與模設(shè)計（第二版）p49表3-8可得：橫搭邊a1=1.0，步距S=159；條料寬度B=D+2a1=159+21.0=161。3.材料利用率一個步距的材料利用率：=ASB100=77.5,排樣圖如圖1.0-7所示。圖1.0-71.0-7排排樣圖五沖壓力計算1.落料查冷沖模具設(shè)計典型實例詳解p138得落料力公式F落料=Ltb=（1591295）N=147356.4N，b為板料抗拉強度，08鋼的b295MPa，取295MPa。2.正拉深查沖壓工藝模具學（第三版）經(jīng)驗公式為：F1=d1tbk1=9012950.9377570.6（N）查冷沖模具設(shè)計典型實例詳解p139表5-1得k1=0.93由于正拉深時采用了壓邊圈，需計算壓邊力，由實用沖壓模具設(shè)計手冊p121表3-65查得壓邊力FQ(N)的計算公式為：FQ=4D-(d1-2t+2rd)q=3.144159-（90-2+22）2.5=3235.0N式中單位壓力q由實用沖壓模具設(shè)計手冊p122表3-66查得，q=2.5MPa。3.反拉深因為反拉深一定是再拉深，所以在計算反拉深力時可根據(jù)再拉深的拉深力計算公式求得：F2=d2tbk2=（47+2）12951.359005.3（N）式中k2由實用沖壓模具設(shè)計手冊P123中表3-70經(jīng)差值法求得。4.沖孔沖孔直徑為36mm，F(xiàn)沖孔=Ltb=361295=33346.8（N）六工作零件刃口尺寸的計算1.落料落料凹模、落料凸模采用分別加工法加工。落料件尺寸為1590-0.16mm。根據(jù)t=1mm，查沖壓成形工藝與模設(shè)計（第二版）p41表3-5得：Zmin=0.100，Zmax=0.140。因為落料件的尺寸精度為IT10級，由沖壓成形工藝與模設(shè)計（第二版）p37表3-2得，所以落料凹模尺寸精度為IT8級，落料凸模尺寸精度為IT7級。查公差與配合合技術(shù)手冊表1-2得凹模尺寸上偏差d=+0.063，凸模尺寸下偏差p=-0.040，因為尺寸精度為IT10以上所以x=1。|p|+|d|=0.103ZmaxZmin=0.140-0.100=0.040mm說明所取凸凹模公差不能滿足|p|+|d|ZmaxZmin的條件，可調(diào)整如下：p=0.4ZmaxZmin=0.40.040=0.016mmd=0.6ZmaxZmin=0.60.040=0.024mm落料凹模刃口尺寸Dd=（Zmax-x）+d0=（159-10.16）+0.0240=158.84+0.0240（mm）落料凸模刃口尺寸Dp=（Dd-Zmin）0p=（158.84-0.100）0-0.016=158.740-0.016（mm）表表3-53-5沖裁模初始間隙值沖裁模初始間隙值2.正拉深正拉深的尺寸為900-0.14mm（1）圓角半徑拉深凹模的圓角半徑可按沖壓成形工藝與模設(shè)計（第二版）p164中經(jīng)驗公式確定：r=0.8（D-d）t=0.8159-901.06.65mm，取7mm。一次拉深成型中，凸模的圓角半徑rp應(yīng)與工件的圓角半徑相等。但對于厚度小于6mm的材料，其數(shù)值不得小于2t。驗證r=2mm=2t，符合要求，不需要再加入整形工序，所以凸模的圓角半徑rp=2mm。（2）間隙拉深模的凸模及凹模的單邊間隙,由于正拉深采用了壓邊圈,這時間隙數(shù)值可以按沖壓成形工藝與模設(shè)計（第二版）p166中表5-19取值，取值為單邊間隙Z=(11.1)t取Z=1.05mm（3）拉深凸凹模工作部分尺寸的確定由沖壓成形工藝與模設(shè)計（第二版）p166得拉深凹模尺寸所以Dd=（90-0.750.14）+0.0350=89.895+0.0350拉深凸模尺寸按凹模實際尺寸配作，保證單面間隙為1.05mm。七沖壓設(shè)備的選擇由于零件屬于中小型沖壓件，且需要拉深工序，所以沖壓設(shè)備類型初步選為開式壓力機。下面進行規(guī)格選擇。1.壓力機噸位計算F復(fù)合模=F落料+F正拉深+F壓邊=147356.4N+77570.6N+3235.0N=228162.0N=228.1620KNF反拉深模=F反拉深=59005.3N=59.0053KNF沖孔模=F沖孔=33346.8N=33.3468KN但是，沖壓過程中最大作用力Pmax發(fā)生的時間很難與標定壓力機的名義壓力位置相重合。這時便不能單純地按最大作用力與壓力機名義壓力之間的關(guān)系來選擇設(shè)備的噸位，而應(yīng)該以保證壓力機全部行程范圍內(nèi)，為完成加工所需的滑塊作用力都不能超出壓力機允許壓力與行程關(guān)系的范圍為條件來選擇。由于沒有壓力機容許負荷曲線，所以參照參考書中壓力機噸位選擇中相關(guān)計算公式得：F總壓力=（0.50.6）F壓力機因此壓力機計算壓力為：F復(fù)合模壓力機=F復(fù)合模（0.50.6）=228.1620(0.50.6)=(456.3380.2)KNF反拉深壓力機=F反拉深（0.50.6）=59.0053(0.50.6)=(118.098.3)KNF沖孔壓力機=F沖孔（0.50.6）=33.3468(0.50.6)=(66.755.6)KN根據(jù)上述計算壓力，落料拉深復(fù)合模選定公稱壓力為630KN的壓力機，反拉深模選定公稱壓力為100KN的壓力機，沖孔模選定公稱壓力為63KN的壓力機。2.滑塊行程由沖壓成型工藝與模具設(shè)計（第二版）p8可知滑塊行程應(yīng)能保證毛坯的順利放進與零件取出。在沖裁時，壓力機并不需要太大的滑塊行程，滑塊行程只要比凹模與卸料板上板料的距離大（23）mm即可。在進行拉深時，行程一般取拉深件高度的（22.5）倍。3.裝模高度由沖壓成型工藝與模具設(shè)計（第二版）p9可知模具閉合高度的值應(yīng)小于壓力機連桿調(diào)節(jié)到最短距離時，由壓力機墊板上表面到滑塊底平面的距離，其關(guān)系為Hmax=Hm+5，式中Hm模具的閉合高度（mm）。綜合以上要求，落料拉深復(fù)合模選擇的壓力機型號為JB23-63開式雙柱可傾式壓力機；反拉深模選擇的壓力機型號為J23-10開式雙柱可傾式壓力機；沖孔模選擇的壓力機型號為J23-6.3開式雙柱可傾式壓力機。4.壓力機功率的核算（1）計算壓力機的有效功在根據(jù)沖壓力選擇壓力機后，還必須核算該項壓力機的功率（功）是否適合。壓力機的一個行程所產(chǎn)生的有效功Wp應(yīng)大于沖壓所需要的總變形功Wb及壓縮彈頂裝置所需的功W之和，即WpWb+W壓力機的功由飛輪的有效能量和電動機輸出的能量所組成。后者主要消耗在克服摩擦和床身彈性的能量等有害阻力以及恢復(fù)飛輪在沖壓后降低的速度上。在實際生產(chǎn)過程中，由于缺少具體數(shù)據(jù)，很難定量計算。根據(jù)壓力機型式標準行程壓力機行程數(shù)，試算得：壓力機行程數(shù)n=340P=340800=63.9(次min)64(次min)單行程有效功Wp=0.14(P)=0.14(800)=3167.8(N.m)（2）每道沖壓工序有效沖壓功落料沖壓功W落料=F落料t=147356.40.001=147.4（N.m）90mm拉深功W拉深=F正拉深h外=77570.60.034=2637.4（N.m）47mm拉深功W反拉深=F反拉深h內(nèi)=59005.30.020=1180.1（N.m）36mm孔沖壓功W沖孔=F沖孔t=33346.80.001=33.3（N.m）有效沖壓功Wb=W落料+W拉深+W反拉深+W沖孔=3998.2（N.m）八模具結(jié)構(gòu)選擇（1）沖模結(jié)構(gòu)形式。由沖壓工藝分析可知，采用一套復(fù)合模，兩套單工序模。（2）定位方式。因為該模具采用的是條料，控制條料送進方向采用導(dǎo)料銷，控制條料的送進步距采用固定擋料銷定距。（3）卸料、出件方式的選擇。根據(jù)零件的形狀和工藝方案，沖裁后的工藝廢料留在條料上，不需采用卸料裝置。工件由于采用了兩道拉深工序，所以采用頂件器頂出。（4）導(dǎo)向裝置的選擇。選擇后側(cè)導(dǎo)柱模架，該模架可用于沖壓較寬條料，送料及操作方便，可縱向或橫向送料。凹模周界范圍為250mm250mm。九落料拉深復(fù)合模主要零部件的設(shè)計1.工作零件a落料凹模尺寸凹模設(shè)計時應(yīng)該考慮凹模強度，制造方法和加工精度等。落料凹模采用凹模板，凹模刃口孔型采用階梯式，刃口的強度好，刃口尺寸不隨修磨刃口而增大。查課本表3-24，表3-25，得系數(shù)k=0.2，送料方向的凹模刃壁到凹模邊緣的最小距離161，送料方向的凹模刃壁間的最大距離161mm，垂直于送料方向的凹模刃壁間的最大距離161mm。根據(jù)課本公式（3-13）（3-32）（3-33），得凹模厚度H=sk=161x0.2=32.2mm凹模寬度s+2s=137+2x40=217凹模長度s+2s+137+2x40=217根據(jù)計算得出的長寬厚尺寸與凹模板的標準進行對照，為使模具結(jié)構(gòu)合理，選用凹模板LBH=25025040。根據(jù)模具的總體輪廓和結(jié)構(gòu)，初選緊固螺釘和銷釘，凹模需要淬火，凹模上螺釘孔和銷釘孔的主要參數(shù)如下：螺孔中心到凹模外緣等距，孔中心到外緣的距離為L=2d=212=24；查課本表2-19，得銷孔中心到凹模外緣最小距離，??；螺孔中心刃口邊緣及銷孔邊緣的距離，標準尺寸：s2d=24；查課本表2-20，得凹模板、凸模固定板上螺孔之間中心距Smin=60，Smax=115b拉深凸模和凸凹模拉深凸模的結(jié)構(gòu)采用典型圓凸模結(jié)構(gòu)，下端為工作部分，中間的圓柱部分用來與凸模固定板配合，最上端的臺肩用于固定并承受卸料力等，各部分的直徑尺寸根據(jù)模具的結(jié)構(gòu)確定。凸凹模的結(jié)構(gòu)也采用典型圓凸模的結(jié)構(gòu)，與拉深凸模相同。其中凸凹模的拉深部分根據(jù)模具的整體結(jié)構(gòu)設(shè)計延伸。由以上工作零件的刃口尺寸計算，可知拉深凸模與拉深凹模的圓角半徑均為5mm，根據(jù)模具結(jié)構(gòu)及課本式（3-26），得拉深凸模長度l=40+24-1=63mm凸凹模長度l=24+36=60mm凹模設(shè)計圖如圖1.0-8所示：由工作零件的刃口尺寸計算結(jié)果，可知凸模的直徑都較大，凸模的剛度和強度都足夠，可不用進行強度和剛度的校核。圖1.0-8凹模2.其他板類零件根據(jù)經(jīng)驗，固定板的厚度取凹模厚度的0.60.8，所以H=400.8=32，查標準手冊，取固定板厚度H=24mm。由以上計算，可知拉深凸模承受的總壓力Fz=F首次=33175.2N，凸模頭部端面直徑，根據(jù)課本公式（3-42），得凸模頭部端面直徑對模座的單位面積壓力查課本表3-34，可知，即拉深凸模與模座之間不需要加墊板。對于凸凹模，凸凹模與模座之間也不需要加墊板，但考慮到模柄的安裝，為了避免模柄對凸凹模的沖擊，應(yīng)該加上墊板。根據(jù)凹模板的外形尺寸及以上計算，查標準手冊，選定上固定板，下固定板，墊板。上固定板設(shè)計圖如圖1.0-9所示：3.壓料裝置根據(jù)模具的總體結(jié)構(gòu)，該模具的壓料裝置援用彈性壓料裝置，彈性元件為橡膠，這種壓料裝置結(jié)構(gòu)簡單，在中小型壓力機上使用較為方便，滿足模具使用的要求。壓料圈采用平面形，根據(jù)零件及模具結(jié)構(gòu)設(shè)計為圓形。頂桿參照部標，選用B10130QJ717-82。4.定位裝置條料在送進過程中，采用導(dǎo)料銷控制送進方向，采用固定擋料銷定位控制送進距離。選用1個擋料銷和兩個導(dǎo)料銷固定在凹模上，查標準QJ702-82選取圖1.0-91.0-9的擋料銷，這種定位零件結(jié)構(gòu)簡單、制造、使用方便。5.卸料裝置根據(jù)排樣圖，為了使模具結(jié)構(gòu)簡單，廢料從凸凹模上卸下不需要卸料裝置。工件的推件動作由剛性推件裝置完成，根據(jù)工件形狀與模具結(jié)構(gòu)設(shè)計，由打桿、螺母、推板組成。參照標準手冊，打桿選用M16186GB2867.1-81，螺母選用M16GB/T41-2000。圖1.0-101.0-10壓邊圈圈6.模架及其零件該模具主要完成落料-首次拉深工序，該工序件的結(jié)構(gòu)簡單，精度沒有嚴格要求，所以采用對此要求不高、送料及操作方便的后側(cè)式導(dǎo)柱模架。根據(jù)凹模板的外形尺寸，查手冊選取凹模周界，的后側(cè)導(dǎo)柱模架。中間導(dǎo)柱上模座25025045GB/T2855.6中間導(dǎo)柱下模座25025055GB/T2855.6根據(jù)模具的結(jié)構(gòu)特點選用壓入式模柄，與上模座采用H7/m6的過渡配合，并加銷釘防轉(zhuǎn)，模柄工作段的直徑與所選壓力機滑塊模柄孔直徑相一致。模柄A5045GB/T2646.1根據(jù)模架及模具的結(jié)構(gòu)特點選取導(dǎo)柱導(dǎo)套。導(dǎo)柱A35180GB/T2861.1導(dǎo)套A35H611543GB/T2861.1根據(jù)模具的總體結(jié)構(gòu)輪廓，查手冊選用螺釘、銷釘如下：螺釘M1265GB70-76M1670GB70-76銷釘1280GB119-861680GB119-867.繪制落料拉深復(fù)合模裝配圖模具裝配圖如圖1.0-11所示圖1.0-111.0-11落料拉深復(fù)合模落料拉深復(fù)合模8.壓力機閉合高度的校核由模具總裝圖可知，模具的閉合剛度。查課本附錄5，可知壓力機的最大閉合高度，連桿調(diào)節(jié)長度，所以壓力機的最小閉合高度,墊板厚度,根據(jù)課本公式（2-1），得所以，可知所選壓力機合適。結(jié)論（總結(jié)）這次畢業(yè)設(shè)計所面臨的任務(wù)是帶輪，通過各種計算還有分析，最終決定的工藝方案是落料、正拉深、反拉深、沖孔。于是選擇了三套模具來完成：落料拉深復(fù)合模，反拉深模，沖孔模。通過這次帶輪的設(shè)計，我又一次體會到了在模具設(shè)計時必須具有嚴謹?shù)膽B(tài)度和足夠的耐心。因為模具設(shè)計是一個特別繁瑣的過程，我們設(shè)計的每一個零部件都要滿足零件的加工要求，所以每一個數(shù)據(jù)都要準確，都要經(jīng)過反復(fù)的琢磨。雖然這是一次畢業(yè)設(shè)計，是學校對我們的一種檢驗，但是我們卻不能只是抱著完成任務(wù)的這種心態(tài)，覺得差不多就行了，而應(yīng)該盡全力把它做到最好。因為一旦我們畢業(yè)步入社會中就會面臨更大的壓力，我們設(shè)計的任何產(chǎn)品都要經(jīng)過社會的檢驗，不能出半點差錯，因此我們從現(xiàn)在開始就要培養(yǎng)這種心態(tài)。另外，這次課程設(shè)計又讓我將三年以來所學的知識復(fù)習鞏固了一下，同時又有了一定程度的提高。因此我相信以后只要我們認真對待每一件事，一定會有或大或小的收獲。謝謝大家THANK YOU趙岐導(dǎo)師：李奇涵李興興THANKS再次感謝再次感謝 畢業(yè)設(shè)計（論文）答辯考核記錄表 機電工程學院 專業(yè) ：機械工程 班級：機械工程144 姓名：朱同 題 目： 輸送機帶輪沖壓成形工藝設(shè)計及模具設(shè)計 考 核 項 目 滿分值 得分 設(shè)計過程中的態(tài)度和能力表現(xiàn)（指導(dǎo)教師在答辯前填好） 1．學習態(tài)度 5 2．基本理論與專業(yè)知識掌握情況及獨立分析和解決問題的能力 15 評閱人評定 3．畢業(yè)設(shè)計（論文）、譯文 5 設(shè)計（論文）的質(zhì)量 （評委當場評定） 4．畢業(yè)設(shè)計（論文）質(zhì)量（設(shè)計結(jié)構(gòu)方案、圖紙、計算、外文） 30 5．設(shè)計（論文）的新見解及成果 5 答 辯 情 況 （評委當場評定） 6．自述情況 10 7．回答問題 30 評委簽字： 合計 幾 點 說 明： A、1．2由指導(dǎo)教師填寫3.由評閱人答辯前填好，否則該生不得進行答辯。 B、4．5．6．7由評委獨立評定。設(shè)計（論文）質(zhì)量的外文部分為5分，中文部分為20分。每個學生的外文翻譯不得少于3000漢字，另外必須用中、外文書寫畢業(yè)設(shè)計（論文）摘要。譯文需指導(dǎo)教師審改簽字，確認非抄襲，并附上原文，系、學院、教務(wù)處有權(quán)抽查考核。發(fā)現(xiàn)抄襲取消答辯資格，并追究指導(dǎo)教師責任。沒有外文翻譯不得參加答辯。 C、每一答辯小組答辯委員會不得少于5人。核分時將各評委所給分數(shù)去掉一個最高分和一個最低分后，再算其平均分數(shù)，并依此由各學院答辯委員會根據(jù)“優(yōu)秀”者嚴控（15%—20%）、“良”者適控（30%-40%）、“不及格”者慎重的原則加以平衡，按優(yōu)、良、中、及格、不及格五級記載。 2018年 06月 15日 Maciej SZAFARCZYK Jarosaw CHRZANOWSKI Radosaw GOCINIAK Warsaw University of Technology, Warsaw, Poland STRAIN GAUGE TOOL PROBE FOR NC LATHES Keywords: tool probe, strain gauge sensor, tool wear measurement, direct tool wear measurement. ABSTRACT The main role of tool probes in NC machine tools. The probes used now in industry and their drawbacks. The original concept of a tool probe using full strain gauge bridges for orientation of tool edges in four directions: +X, -X, +Z, -Z and for direct tool wear measurement. 1. INTRODUCTION The rapid development of all areas of manufacturing technology and the aim to reduce costs, increase precision and to shorten production time are enforcing the use of modern production technology. Dimensional parameters are the most commonly encountered quality characteristics of workpieces. Conventional machine tools are gradually being replaced in production plants by modern manufacturing systems, components of which, in the case of machining, are CNC machines. Main new CNC machines operate several different tools. To increase dimensions accuracy of components manufactured in CNC lathes we must use tool setting systems to know how the tools are located on the machine. Using traditional techniques, tool setting is time consuming and can be prone to human error. A touch probe system is an inspection equipment that allows a machine tool to perform geometrical measurements inside its working area, but besides tool tip coordinate identification, we must have information about tool wear. * The project has been financed from Multi-Year Programme PW-004, Institute for Sustainable Technologies - National Research Institute (ITeE - PIB) From all elements of manufacturing systems cutting edges wear is the fastest. In case of total wear we must replace a worn out tool with a sharp one. Cutting edge wear starts from first moment when touching the working material. Tool wear may be gradually, in case mechanical, chemical or temperature activity in turning process and we call them natural wear. In some cases tool wear is sudden when we have forces above the yield point and we call them catastrophic tool breakage (KSO). 2. INDUSTRIAL TOOL SETTING SYSTEMS When clamping a new tool on the machine or after the replacement of a worn out tool with a sharp one we must have information about orientation of tool edge. During writing the part program, the path of the tool tip is described by an assumed system co-ordinates, without knowing how the tools will be located in the machine. The corrective coordinates are defined during the orientation of the tool tip by the tool probe, and are then entered for every tool in the tool table stored in the machine control unit. While interpreting, the machine controller adjusts the points of the edge path by the values read from tool table. Figure 1 presents use of a standard touch trigger probe system for determination of X co-ordinate of the tool edge. Fig. 1. The use of a standard touch trigger probe system for determination of X co-ordinate of the tool edge 1. When tool tip touches probe stylus, the contact sensors in its result are opened, the value of the coordinate of the location of the saddle, which is read from the machine measuring system, is automatically entered into the register of the control unit reflecting the number of the measured tool and then the saddle motion is switched off. These probes only need to signalize that contact between tool tip and probe stylus was occurred. Standard tool setting system used touch-trigger probes. The most known is RP3 probing system (Figure 2) designed by Renishaw 2, 3. Fig. 2. Renishaw RP3 probe 3. The sensing of contact between workpiece and the probe is done by electric switches, witch strongly determine the repeatability and accuracy of probing. The original touch-trigger probe also called kinematic resistive Probe” (Figure 3), works with a set of three cylindrical pegs attached to the stylus. Each of them rests on two separated electric contacts that gives altogether six points of constraint for the six degrees of freedom of the stylus. An electric circuit is built out of these contacts, which is closed, when the stylus is in its neutral position. When the stylus touches the tool tip a further constraint point is added and so the pressure on one of the original constraint points is reduced, which changes the resistance of the electric circuit. The contact between stylus and tool tip is signaled when a certain threshold value of resistance is exceeded. Fig. 3. Touch-trigger probe 4. 3. INDUSTRIAL TOOL MONITORING SYSTEMS KSO must be detected very fast and after that we must provide necessary changes in turning process. That means that automation of turning process needs automatic detect and properly react in case of KSO. Method and range of this monitoring depend on process type. We have many industrial systems which can detect KSO. Natural wear is difficult to measure, but we dont need fast reaction from monitoring systems the reason are continuous changes of tool wear value. We have many industrial types of tool monitoring systems (Figure 4.), we measure: - cutting forces - effective power - torque - acoustic emission - differential pressure - distance measuring with cooling lubricant - jet barrier using laser, air or cooling lubricant Fig. 4. Tool monitoring systems (Nordmann). 5 We can mark out two types of monitoring in-process: monitoring and post-process tool monitoring. POST-PROCESS TOOL MONITORING Post-process tool monitoring is tantamount to geometry control of the tool cutting edge before or after the chip producing process with feelers, light barriers, or similar devices. Pro: - Sometimes high certainty of detection of breakage - Typically easier usage Contra: - Measurement can lengthen the production time - Machine is only stopped after tool breakage, i.e. possible damage to the work piece or the machine or the tool holder as a result of the forces incurred - Not all testing methods are free of wear IN-PROCESS TOOL MONITORING Indirect control during the metal cutting process of effective power, cutting force, or acoustic emission. Pro: - The measurement does not extend the production time - Machine is stopped at the moment of tool breakage - No additional installations (e.g. control switch) are necessary near the tool - Loss-free sensors. Contra: - Does not offer 100% guarantee of detection for all tool breakage - Sometimes the breakage is only detected when the next work piece is cut, e.g. in the case of thread cutting control with effective power and breakage at the moment of reversal of spin direction. All above industrial systems are not provide direct natural tool wear measurement. These methods mainly detect moment of the tool breakage or measure physical process parameters and based on these data, calculate natural tool wear. Mathematical description must include many process variables (e.g. heat expansion), consequently method based on mathematical models may have many errors even in self mathematical model which is only approximation of real process. 4. ORIGINAL PROBES FOR DIRECT TOOL WEAR MEASUREMENT AND FOR TOOL SETTING DESIGNED IN WARSAW UNIVERSITY OF TECHNOLOGY - STRAIN GAUGE PROBE A. PROBE FOR TOOL SETTING This is a new probe for identification of a tool tip co-ordinates on an NC lathes and for tool setting 6. The main part of this probe is a round bar. Stylus with crash protection device is connected with bar. The bar has two parallel flat surfaces on a part of its length. They are oriented under angle 45 in respect to X and Z axes of NC lathe (Figure 5). Fig. 5. Original measurement conception 7. Four strain gauges are glued on those flat surfaces (two of them are placed on the one side and the two other on the opposite side), the strain gauges are connected in a full bridge with all active gauges. This original design allows the possibility of tool tip co-ordinate identification in four directions of tool movement (-X, +X, -Z, +Z NC lathe axes) using only one full bridge sensor. When tool tip touches the probe stylus and moves forward, it deforms the flat and flexible part of bar. The maximum value of deformation must be kept below yield point defined by material properties. An actual value of analog electrical signal from strain gauges is compared continuously with a defined level of signal. When compared signals are equal, the comparator sends a signal to a NC machine controller to read value of the co-ordinate of location of the saddle from linear scale. The probe accuracy is placed in repeatability of generating this signal by comparator. Acceptable repeatability must be near 1m. B. PROBE FOR MEASURING TOOL WEAR Next probe is designed for both tool co-ordinate identification and tool wear evaluation in turning (Figure 7). The newest conception gives a possibility measuring the natural wear at the tool tip in the same time as identification of the tool co-ordinates. It is significant that both measuring components of the probe meet directly on the cutting plate. This allowed for elimination of errors e.g. unequal heat expansion of the seat and this plate. Strain gauges are mounted on the flexible sleeve and on the flat part of the bar (Figure 8). Worn part of the tool tip touches the first plate mounted on the bar, in next step base part of the tip (not worn) touches the second plate mounted on the sleeve. We have signals from both full strain bridges. Fig. 7. Tool probe for measuring tool wear. Fig. 8. Probe construction. Measurement of the new insert is used as a reference. During measurements after machining the obtained value is subtracted from the reference one and calculates current wear of the cutting edge (KE) (Figure 9). Fig. 9. KE calculation. When tool moves and touches plate mounted on the bar and flexing the bar. Reaching defined level of signal from strain gauges mounted on the bar is signaled by sending digital signal to machine control unit to identify tool tip coordinate. We also have continuous analog signal from gauges and we can calculate this signal to the value of plate dislocation. When tool moves forward not worn part of the tool tip touches second plate mounted on the sleeve and flexing the sleeve. Reaching defined level of signal is signaled by sending digital signal to control unit to remember actual analog value from gauges mounted on the bar. This value (subtracted to the reference one) is the current tool wear value (KE). We will try to use Siemens Siwarex U (Figure 10)- weighing module as a transducer. We can connect to them 2 full strain bridges and sending signals to machine control unit. We also consider building own control unit with cooperation with polish company ZEPWN 8. Fig. 10. Siemens Siwarex U weighing module 9. 5. CONCLUSION This probe will be an alternate solution in comparison with a standard tool probe. The strain gauges were never being used as a main part of a tool probe. The results of first tests demonstrate, that a probe with a strain gauge sensor based on presented original measurement conception, is suitable for both orientating the tool tip in the NC lathe co-ordinates and for tool wear measurement. After all tests we will try to adjust the probe for industrial application. REFERENCES 1. Coleman D., Waters F.: Fundamentals of touch trigger probing. 1997, Touch Trigger Press 2. Renishaw.: RP1 & RP2 Tool Setting Probe data sheet 3. RP3 Tool Setting Probe data sheet 4. A. Weckenmann, T. Estler, G. Peggs, D. McMurtry.: Probing Systems in Dimensional Metrology CIRP Annals STC P, 53/2/2004, p. 657 5. www.nordmann.de 6. Szafarczyk M., Winiarski A.: Tool probe. Patent application P.378785 Warszawa, 02.2006 r. 7. Gociniak R.: Strain gauge tool probe for NC lathes. 2006 IV International Conference on Machining and Measurement of Sculptured Surfaces 8. Zakad Elektroniki Pomiarowej Wielkoci Nieelektrycznych .pl 9. Siemens Siemens Siwarex U (One and Two-Channel Model) Equipment Manual. Relase 06/2005