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NGHIEN CUTU - TRAO D | 'THI6T K€ VA M PHONG CO CAU AN DAO CHINH XAC DESIGN AND SIMULATION OF HIGH PRECISION FEED DRIVE Pham Minh Tuan', Pham Huy Hoang^ 'Khoa Cd khi, Trfldng Dai hpc Bach khoa TR Hd Chi Minh ^Trung tdm Dao tao Bao dfldng Cdng nghiep, Trfldng Dai hpc Bach Khoa TR Hd Chi Minh TOM TAT Mac du cd cdu dn dao cdc mdy cdng cu ngdy gdn nhU da trd nin hodn thien, ddc biet Id cdc mdy CNC hien dai Tuy nhien, chung vdn cdn mot sd han che cd htiu khien chinh xdc gia cdng bi han chid mtic tren ^m Mdt sd nhUng nguyen nhdn quan nhdt chinh Id sai sd cdc khdp ndi truyen thdng, chdng han nhU khe hd vit me bi, dldn, Do phdn gidi chuyen ddng cua nhiing cd cdu dn dao hien dai cd the dat den (Am nhting bi dnh hudng bdi cdc sai sd nen chinh xdc gia cdng tren cdc mdy ndy gidm xudng vd tin cay cua chdt lUdng sdn pham Id khdng ddm bdo Tat cd sai so ciia khdp ndi truyin thdng cd the hodn todn bi loai bd sti dung khdp ndi ddn hoi Cd cau dan hdi cdu tao tii cdc khdp ndi dan hoi cd the truyen chuyen ddng vdi chinh xdc cao md khdng tdn tai cdc sai sdcdbdn nhUkhe hdhay mdn vd dnh htidng nhiet Itic ma sdt Bdi bdo ndy trinh bdy mot thiet ke mdi cho cd cdu dn dao chinh xdc sti dung cd cdu ddn hdi vd cd cdu chap hdnh piezo Tfl khda: Cd cau dn dao chinh xdc; Bd phan chay dao cdi tien; Khdp ndi ddn hdi; Cd cdu dan hdi; Cd cdu chap hdnh piezo ABSTRACT Although the feed drives of modern machine tools are almost impeccable, especially in CNC machine, they still have some unexpected errors so that the manufacturing accuracy is always limited above (tm One of the most important reason is errors of traditional joints, such as backlash in ball screws, bearings, The resolution of feed drives is ^m but it is affected by above errors, therefore the accuracy offeed drives is reduced and the precision of products is unreliability All errors of traditional joint can be totally eliminated by using flexure hinges The compliant mechanism using flexure hinges can transmit motion with high accuracy and does not contain any errors like backlash or wearing and thermal effects by friction forces The paper presents a new design of high accuracy feed drive using compliant mechanism and piezo actuator Some FEM and dynamic simulations are also executed to ensure the reliability of results Keywords: High accurate feed drive; Precision feed drive; Flexure hinge; Compliant mechanism; Piezoelectric actuator TAP CHi CO KHi VIET NAM, Sd 12 nam 2013 HH NGHIEN CJU - TRAO DOI GIOI THIEU Hien nay, nhilu nghien cflu da dfldc thflc hien nham cai thien va ndng cao dp chinh xac gia cdng cat gpt Biln phap biln nhat la thiet k l cdi tilt kit cau mdy, dac bilt la cd cau an dao d l ndng cao dp chinh xac vi tri cua dung cu cat [1, 2] Mdt hfldng nghien cflu mdi la thiet k l dung cu cat kim cfldng dung gia cdng cac chi tilt quang hoc [4, 5] hoac khao sat ddng lflc hpc de tinh toan bu trfl sai sd qua trinh gia cdng [3, 6] D l dat dflpc dp chinh xdc vi tri cao gia cdng, chuyen ddng dau vao cua ca cm an dao thfldng dfldc cung cap bdi ngudn dan dpng chinh xdc nhfl ca cau chap hanh piezo hoac dpng cd servo Phan Idn nghien cflu tap trung vao giai quylt sai sd qua trinh gia cdng d l nang cao dp chinh xac va ndng cao kha nang gia cdng cac chi tilt quang hpc tren may tien Tuy nhien, hau nhfl chfla cd nghien cflu nao di vao van de cai tiln cdc mdy cdng cu hien cd d l nang cao dp chinh xdc an dao cua cac may Vdi nhilu flu dilm Idn truyen chuyin ddng chinh xac nen viec sfl dung cd cau dan hdi gia cdng chinh xac la rat hflu ich Cu the, nlu ngudn chuyin ddng dau vao cd dp chinh xac cao, chang han sfl dung piezo actuator, qua ca cau dan hdi d l truyen va biln doi chuyen ddng thi dau cd t h i dat dfldc dp chinh xac vi tri rat cao Do dd, van de nghien cflu ca cau chay dao may tien sfl dung co cau dan hdi va piezo actuator la rat quan trpng va mang nhilu y nghia thflc tien Tuy nhien, vdi kha nang truyen chuyen ddng nhd va chinh xac thi cd cau an dao sfl dung ca cdu dan hdi va piezo actuator chi nen sfl dung gia cdng tinh Trong tinh hinh san xuat ca cua Viet Nam, cac may cdng cu va may CNC dflpc sfl dung biln hau hit Id t h i he cu, dp chinh xac thap nIn chat Ifldng san pham khdng cao Do do, viec sfl dung cd cau an dao flng dung cd cau dan hoi de gia cdng tinh cd t h i cai thien dflpc chat Ifldng san pham ma mflc dau tfl khdng cao, khdng can mua may mdc - thilt bi mdi, tan dung dfldc cdc mdy mdc t h i he cu ma van cd t h i c h i tao dfldc sdn pham cd dp chinh xac cao vdi gid re Bai bdo trinh bay qud trinh thiet kl, mo phdng, phdn tich ddng lflc hpc cua ca cau an dao chinh xac sfl dung cd cau chap hdnh piezo va co cau dan hdi Cd cdu an dao chinh xdc phai dfldc thilt k l nhd gpn, phu hdp lap rdp t r l n ca cau an dao cua cdc may cdng cu biln THIET KE C O CAU D A N HOI DtJNG TRONG C O CAU A N DAO C H i N H XAC Ca cau an dao dfldc cai tiln cd t h i dat dp chinh xdc rat cao nhd sfl dung cd cau chap hanh piezo la ngudn cung cap chuyin ddng va cd cdu dan hdi d l truyen chuyen ddng Tat cd cac thdnh phan phai dfldc thiet ke hdp ly cho cd the bd tri de dang tren ca cau an dao cd san cua may tien va ludn boat ddng thuan ldi mpi dieu kien gia cdng / \ Chuyen dong hu6n% Irinh cua b ^ phan chay dao chinh xac »/ If A^ Ciinbicndo dich chuyen Cor cau dan hoi —' M,\m d.ia / Chuyen dong doc tryc ciia / ho ph^n chay dao thuong ft ,/f/ Chuyen dong BU ~ hiiong kinh ciia jH',* H Pif^ W phan chay Wl 1? daolhiccrog au chap hanh piezo Hinh 1: t tUdng thii't ki'cua cd cdu an dao chinh xdc Ngoai ra, d l phu hdp vdi khdng gian lap rap tren may thflc t l cd t h i ban hep, cd cau dan hdi phai dfldc thiet ke nhd gpn nhflng van dam bao truyen chuyin ddng chinh xac Vi mdt s6 may tien bi gidi han ve khdng gian chuyin dpr^ dpc true cua ca cau an dao nen de dam bao thuan ldi cho qua trinh lap rap, cd cau ddn hdi dfl