NGHIEN CUfU - TRAO OOl
VKY KY THUAT VIET CHLCANG TRINH NC GIA CONG MOT SO CHI TIET DAC BIET THEO PHL^ANG PHAP TQA DO VDL S I /
H 6 TRO TINH TOAN CUA PHAN MEM MAPLE
WRITING TECHNIQUE OF NC PROGRAM PRODUCING SOME SPECIAL DETAILS ACCORDING TO COORDINATED METHOD
WITH THE CALCULATION SUPPORT OF MAPLE SOFTWARE
ThS. TranNgocHai
Khoa Ca khi, Triicfng Dai hoc Kinh te Ky thuat Cong nghiep
TOMTAT
Bdi bao trinh bay phUdng phap tinh, ky thuat viet chUdng trinh NC gia cdng mot sd chi tiet dac biet theo phUdng phap toa do tren phan mem Maple. De thUc hien yeu cau tren, trong bai trinh bay each vi^t chUdng trinh Maple deve bien dang chi tiet, tinh gia tri toa do cac diem thuoc bien dang chi tiet tU dU lieu ban dau. Tren cd sd cac ket qua do, sU dung ky thuat lap trinh theo phUdng phap toa do viet chUdng trinh NC (Numerical Control) gia cdng chi tiet dat hieu qua cao.
Tii khoa: Lap trinh NC theo phUdng phap toa do.
ABSTRACT
The article presents computing and programming NC code, outsourcing some special models using the coordinated methods on Mapple. To perform the these requirements, the article indicates how to the write maple programs to draw the boundary of the model, compute the coordinate value ofboundaried points from the original data. On the basis of these results, using programming techniques with coordinated methods for writing NC programs (Numerical Control) to machine products with high efficiency.
Keywords: Programming NC using coordinated methods.
TAP CHI CO KHI VIET NAM, So4nam2014
NGHIEN CUfU - TRAO DOI
l . D A T V A N D E
Khi gia cdng cae chi tiet dac biet ma bien dang dUde md ta bdi cac phUdng trinh: DUdng Xicldits, Epixicldit, Caedidit, dUdng axtrdit,.... thi viec viet chUdng trinh NC (Numerical Control) gap rat nhieu khd khan. TrUdc tien tii phUdng trinh da cho phai ve dupe bien dang chi tiet, thUc hien ve theo phUdng phap truyen thdng la thUc sU khd va thieu chinh xac. Cd nhieu hUdng giai quyet khac nhau ve viec ve va viet chUdng trinh NC. Thdng qua mot sd vi du, phan tiep sau day trinh bay phUdng phap tinh, ve bien dang chi tiet va ky thuat viet chUdng trinh NC tUdng Ung de gia cdng.
2. GIAI QUYET VAN DE
Xet bai toan 1: Viet chUdng trinh NC gia cong chi tiet cd bien dang dUdc md ta bdi phUdng trinh dUdng Xicldits: x=r.arccos
'^^^~^y{2r~y){l) r
Gidi han chi tiet trong khoang (0..4TI), trong do: r=15 (ban kinh vong cd sd) chieu rpng bien dang chi tiet: b=6, chieu sau:
h=2,5mm.
+ TrUdc het ta ve bien dang chi tiet tU phUdng trinh da cho.
Hinh 1 la bien dang chi tiet dUdc ve theo phUdng phap truyen thdng (khdng trinh bay each ve). TU hinh 1 ta thay viec ve, xac dinh cac diem M^ thuoc bien dang la khd khan nhat la khi ban kinh vong cd sd r cd gia tri Idn. Vdi mdi gia tri khac nhau cua r lai phai ve mdi cac diem thuoc bien dang chi tiet.
Hinh 1: DUdng Xicldits
Vdi mot each tiep can mdi, thay vi tim each ve bien dang chi tiet chiing toi xac dinh toa do cac diem M^ (x^, y,) thupc bien dang. Vdi sd lUdng cac diem M^ du Idn, noi trdn lai, ta dUdc bien dang chi tiet can tim. Qua trinh duoc thiic hien rat nhanh nhd sU ho trd tinh toan, ve cua phan mem Maple. Tpa dp cac diSm thudc
bi^n dang chi tiet lam ca sd de viet chUdng trinh NC sau nay.
Trinh tU cae bude nhU sau:
a. Lap cdng thxic tinh toa dp cac diem M^(x^, y ) tU phUdng trinh ban dau. Viet chUdng trinh Maple tinh gia tri tpa dp M^(x^, y), ve bien dang chi tiet.
b. Lap bang gia tri tpa dp cac diemM^(x, y ) .
c. Viet chUdng trinh NC gia cdng chi tiet tU bang gia tri tpa do cac diem M^(x, y^). De lam ro qua trinh nay xin theo doi mot so vi du sau:
2.1. Nhflng v i d u
Vi du 1: Viet chUdng trinh NC gia cdng chi tiet cua bai toan 1, thUc hien:
a. Lap cdng thUe tinh tpa dp M^(x., y^): TU phUdng trinh(l)viet lai theo phUdng trinh tham so:
x=r(^-sin(p), y=r(l-cos<p) vdi(0"<9<27T).
Viet chUdng trinh tinh gia tri tpa dp M ( x , y ) , ve bien dang chi tiet, giai thich cac cka lenh cd ban cua Maple (chUdng trinh viet tren Maple 13);
> restart: (Bat dau vdi Maple) with(plots): (Goi cdng cu ve) Digits:=5; (lay chinh xac 5 so sau dau phay)
r:=15; (ban kinh dUdng cd sd) n:=36; (sd diem chia dUdng trdn cd sd)
for i from 0 to n do (bien i chay tU 0 tdi n)
TAP CHI CO KHi VIET NAM, Sd 4 nam 2014
NGHIEN ClJfU-TRAODCl
phi [i]:=2*Pi*i*10/180; (Gdc 9 tinh theo n, 2 Ian chu ky 2Pi) X [i]:=evalf(r*(phi[i]-sin(phi[i]))): (Tinh gia tri x[i]cua diem Mi)
y [i]:^evalf(r*(l-cos(phi[i]))): (Tinh gia tri y[i]cua diem Mi) od; printC'Toa do cac diem M(x,y)thuoc duong XicIoit");(Lenh in)
f:={seq([x[i],y[i]],i=0..36)}; (lap bang tinh gia tri x[i], y[i]
cua Mi)
printC'Duong Xicloit");(Lenh in) plot((f),color=red,thickness=3); (Lenh in)
Hinh 2: Bien dang chi tiet - DUdng Xicldits.
b. Bang tpa dp cac diem M^(x^, y) thupc dUdng Xi- cldits (trich)
'.-">
. ' . = »
.t|:= 0.1059 l|-=0 905
.t. := (J.830:
>• .= 3.509 J,-27.011 y. = 26 491
-t,, =7S.823 .'•,,.= 22 500 ii,:=82.841
^„-17.604
»„.= 94 248
>•„•">-
! „ : = 94.355 y„-'0.%i
',, =112 67 rjj.= 22 50O v„ = 121 26 r„ =26.491
.Tj^ =188 39 v„ =0.905 1^ := 188.50
IV'0
c. Viet chUdng trinh NC: Cac phUdng an dUdc dUa ra de lUa chpn nhU sau:
+ PhUdng an 1: Sli dung npi suy cung trdn G02 hoac G03. Theo phUdng an nay cung trdn cd the dUpc xac dinh theo cac thdng so (hinh 3).
A
—.^ \^\-,' \Endpoml
30 « 50 V-
Hinh 3a: Lap trinh theo thdng so diem dau, diem cuoi, tam. ChUdng trinh:
N5 G90 X30 Y40; (diem bat dau cung trdn NIO).
NIO G02 X50 Y40 KIO I -7,5;
(npi suy cung trdn-di^m cuoi va tam).
Hinh 3b: lap trinh theo thdng sd tam cung trdn va gdc md. ChUdng trinh:
N5 G90 X30 Y40; (diem bat dau cung trdn NIO).
NIO G02 KIO I -7,5 AR=106;
(npi suy cung trdn-diem tam va gdc md).
Nhan thay bien dang chi tiet khdng phai la cung trdn nen thUc te phUdng an (1) khdng sU dung dUpc.
-f- PhUdng an 2: Si£ dung chu trinh gia cdng dUdng cdng, contour tUdng Ung tU cac phan mem CAD/
CAM da chpn. Tuy nhien, do khdng ve dupe chi tiet ma bien dang dUde md ta nhu phUdng trinh (l)...tU Mastercam, Solidworks... do vay, thUe te khdng nhan dUdc sU hd trp tU ddng viet chUdng trinh NC tU cac phan mem CAD/CAM.
-I- PhUdng an 3-PhUdng an lUa chpn: Tren ca sd dieu khien diem- diem, sit dung npi suy tuyen tinh (lenh Line-tUdng dUdng GOI) de viet chUdng trinh NC theo phUdng phap tpa dp, vi du (hinh 4) la each bieu diln xap xi cung trdn ciia (hinh 3) theo
phUdng phap tpa dp. ^
TAP CHI CO KHi VIET NAM, Sd 4 nam 2014
NGHIEN COfU - TRAO D 6 |
Start point
^ ^ ^
End point . ^ End point41 50
Hinh 4a: Dung noi suy tuyen tinh-lenh Line (GOI). Chilong trinh:
N5 L X30 Y40; (diem bat dau xap xi cung tron);
NIO L X40 Y45; (npi suy tuyen tinh tdi diem IVI);
NI5 L X50 Y40; (noi suy tuyen tinh tdi diem cuoi).
L Z+2 XO YD RO FMAX M03(Chay dao nhanh tdi diem z+2, x^.y^, F,„g^,:
L Z-2,5 RO F50 Jyi03;(npi suy tuyen tinli theo chieu Z~2.5, F50);
L X+0.1059 Y0.905 RO F50 M03; (tien dao tii xO tdi x l , yO tdi y l , F50);
L X+0.8302 Y3.509 RO F50 M03; (tien dao tii X| tdi Xj, y^ tdi y^ F50);
( );
Hinh 4b: Khi tang sd diem M^, xap xi cung
tron cang dung. NhU vay, tii bang ket qua gia trj I'X+188.5Y0R0F50M03; (tien dao tii x^^
toa do cac diem M^(x, y,),dimg lenh Line(GOl) ' * ^w Yss ' * Y,s- ^50);
ndi M_ |(x, ,,y |) tdi !VI,(x, y.) ta dUpc bien dang
chi tiet. Til cac phan tich tren ta viet diipcchuang ^ Z+50 RO FMAX M05; (nhac dao len trinh NC (trich - gia cong tren may NOVAMILL- ^"'"^*'' ' ' ^ " S ''"'''^ chinh);
DENFORD).
END PGM 99; (Ket thiic chiiong trinh gia BEGIN FGR 99 MM (bat dau chuang '^°"8'-
trinh);
Vi du 2: Viet chuong trinh NC gia cong BLK FORM 0.1 Z X+0 Y+0 Z-20 (khai ^'^' ' ' ^ ' ^° ^'•™ '*'"S l i philOng trinh diidng bao phoi-diem thap nhat ben trai); epixidoits:
BLK FORM 0.2 X+250 Y+120 ZO (khai bao phoi-diem cao nhat ben phai);
TOOL DEF 1 L+0 R3 (Dat dao so 1- R3);
smtp - n s i n -
X =(R+r)cos(p - r.cos .ip; y =(R+r) r
R + r
7 (2), trong dd:
S=1000):
r =10, R=30 Ian liipt la ban kinh dtldng TOOL CALL 1 Z SIOOO (Gpi dao so 1, tron cd sd, diidng tron dinh hudng.
TAP CHI CO KHi VIET NAM, Sd 4 nam 2014
NGHIEN CUfU - TRAO D O I
Cac biJ6c thiic hien
a. Tii phiiong trinh (2) viet chuong trinh Maple tinh M^(x, y ) , ve chi tiet:
> restart:
with(plots):
R:=30;
r:=10;
for i from Oto 120 do phi[i]:=(Pi»i*3/180);
x [ i ] : = e v a l f ( ( R + r ) * c o s ( p h i [ i ] ) - r » c o s ( ( l / r)*(R+r)»(phi[i]))):
y l i ] : = e v a l f ( ( R + r ) » s i n ( p h i [ i ] ) - r ' ' s i n ( ( l / r)*(R+r)*(phi[i]))):
od;print("Toa do cac diem M(x,y)thuoc duong fipLxicloit");
H:=(seq([x[i],y[i]],i=0..120)};
pointplot((H),cplpr=red);
••*"
-40 2 0 4 0 ' -
20
20 4 0 -20
—40 , ^ '^
L X+30 YO RO F50 MOB; (tien dao thing tii '^ns^Xu.. y„,->-y„„. F50).
END PGM 99; (Ket thilc chilong trinh gia cong).
Vi du 3 : Gia cong chi tiet cd bien dang la phtlong trinh dudng Cacdioit
x=rcos<p (l+cosip); y=rsin(p (l+coscp) (3) trong dd: r = 26.
Cac biidc thtic hien:
a. TCi phUdng trinh (3) Wet chUdng trinh Maple tinh M^(x., y ) , ve chi tiet:
> restart:
with(plots):
r:=26;
fori from Oto 180 do phi[i]:=evalf(Pi*i*2/180);
x[i]:=evalf(r*cos(phi[i])»(l+cos(phiIi]))):
y[i]:=evalf(r*sin(phi[i])*(l+cos(phi[i]))):od;
printC'Toa do cac diem M(x,y)thuoc duong Cacdioit");
H:=(seq((x[i],y[i]],i=0..180));
pointplot((H),color=red);
Hmh 5: Bien dang chi tiet - DUdng Epixicldit b. Bang tpa dp cac diem M|(x^, y ) thupc diidng Epixicldit (trich)
I, =!0 I, =->OI6jl .t,, =92'H| i^--]'>'IV t|_ =!»1M I T -!(I I 1 -0 )',=00[4: , „ - r 5 5 2 ,_, =;SSU r„,:MfJ.JJM_ =0
c. Childng trinh NC gia cong bien dang (trich).
BEGIN PGR 99 M M (bit dau chilong trinh).
L X+30.164 Y0.0144 RO F50 M03; ( t i &
dao thang tit x^^-vx,, y„->y,, F50).
»
20
W
w
-30
-x
ID 20
'*'"',
3D
.,"••
**^
40
^>
••' '•.
°
60
,-
••
..);
Hinh 6: Bien dang chi tiet - Dudng Caedidit.
b. Bang tpa dp cac diem M^(x^, y) thuoc
dudng Cacdioit (trich) ^
TAP CHI CO KHI VIET NAM, So 4 nam 2014
N G H I E N CUfU - TRAO D 6 |
x„:=52.
>V=o-
.v,:= 51.952 y, ;= 1.8142
•Ss--1-2106
>•„:=-0.39342
X 100
•'lOO
= -1.47^
= -0.536
^,„:=51.95:
>-,„:=-1.813
X ;= 52.000
ISO
y^^ := O.O00764(
c. Chilong trinh NC gia cdng bien dang (trich);
BEGIN PGR 99 MM (bit dau chUdng trinh);
LX51.952 Y1.8142 RO F50 M03; (tien dao thang til Xg^x,, yij-^y,, F50);
( );
L X52 Y0.00076 RO F50 M03; (tien dao thang tU x,,^^x,^^, y„,^-y,,n, F50);
END PGM 99; (Ket thiic chUdng trinh gia cdng), 2.2. K^t qua, pham vi uCng dung
Hinh 7,8: Md ta viec SL( dung may NO- VAMILL-DENFORD gia cdng chi tiet bang chuong trinh NC viet theo phuong phap tpa dp dat ket qua tot.
Hinh 7: May NOVAMILL - DENFORD
Hinh 8: Gia cong dUdng Cacdioit.
Pham vi Ung dung: Dung de viet chUcfng trinh NC cho may CNC, may gia cdng vat lieu tam.
3. KET LUAN
Bai bao trinh bay dUpc phUPng phap viet chuong trinh MAPLE de tinh gia tri va ve chinh xac tpa dp cac diem M^(x^, y^) cho cac chi tiet co bien dang dac biet. ChUong trinh tinh cd the de dang dieu chinh cho nhieu chi ti^t phUc tap vcli cac bien dang khac nhau. Ket qua gia tri tpa dp cac diem thupc bien dang se dUcfc dimg lam cd scl de viet chUOng trinh NC gia cdng chi tiet.
Phuong phap de xuat trong bai bao cung rat thich hop khi viet chUOng trinh NC cho cong nghe EDM (Electrical Discharge Machining) gia cdng vat lieu tam cd kich thUdc Idn. Ket qua ki6m nghiem cho chi ti^t mau da dUpc minh hoa tren hinh 8.
Han ch^ Idn nhat cua bai viet la chUa xay dUng dupe sU tUOng thich ciia chUPng trinh MA- PLE sau khi tU dpng tinh, ve bien dang cac chi tiet dac biet vdi chUOng trinh NC dimg cho may gia cdng. Do vay, viec viet chUdng trinh NC dUdc thUc hien thu cdng trUc tiep theo tiing cau lenh, hy vpng rang tdi day vdi sU ho trp cHa phan mem CAM, tren co sd tpa dp, bien dang cac chi tiet d^c biet da xac dinh, bai viet se dat dUpc trinh dp tii ddng lap trinh NC gia cdng chi tiet. • Ngay nhan bai: 20/02/2014 Ngay phan bien: 10/3/2014 Tai lieu tham khao:
[1]. Pham Huy Dien (2007), Day vfl/!pc(ofl«CM«5 mfly tinh.
NXB. Giao due, Ha Noi.
[2]. I r a n Van Dich (2007), Cong nghe CNC. NXB. Khoa hoc Ky thuat.
[3]. Nguyen Dinh Tri (chu bien), Ta Van Dinh, Nguyen H6 Quynh (2007), Toan cao cap tap 3, NXB. Giao due. Ha N6i.
[4]. Trin HQu Que (chii bien), D^ng Van Cii, Nguyen Van Tuan (2007), Ve Icy thuat cd khi tap 1, NXB. Giao due.
• TAP CHI CO KHI VIET NAM, Sd 4 nam 2014
