NGHIEN CUU - Ti^O OOI
MOI QUAN HE GIUfA CAC THONG SO DIEN
von CHIEU RONG RANH CAT KHI GIA CONG CAT DAY TIA LUfA DIEN
( * ) NGUYEN TRONG HIEU NGUYEN DAC TRUNG (**)VU QUANG HA
TOM TAT:
Bai bao trinh ba}- nhiing thdng tin ca ban ve quan he giiia chieu rdng ranh cat da}- vdi cac thdng sd ve dien khi gia edng eat di}- tia lua dien vdi eae loai phdi khae nhau. Ket qua nghien ciru cho phep ngoudi dieu khien may cat da} de dang tim doirpc chieu rdng ranh cat tdi uu.
I. Dat van de
Thuc nghiem cho thay-, chieu rdng ranh eat ldn dan khi tang tri sd cua eae thdng sd edng nghe. Chieu rdng ciia khe hd ranh cat lai anh huong true tiep den dp chinh xae kich thude. Ban dau thi chieu rdng khe hd nhd dan den sai lech kich thudc ldn. Sau dd. khe hd tang dan thi sai sd kich thudc giam dan, dat gia tri nhd nhat. Tiep theo, neu ta tiep tue tang tri sd khe hd bang each tang tri sd eua cac thdng sd cdng nghe thi sai sd kich thudc lai tang len. Vi va}-, can phai tim ra tri sd eua khe hd ranh cat tdi un, de sai sd la nho nhat. Ung vdi cac ehe dd cdng nghe da chpn, ta cd cac dd thi bieu dien mdi quan he giira chieu rdng khe ho ranh cat \'di eae thdng sd ve dien.
IL Noi dung
Tien hanh nghien cim tren phdi thep SKD61 vdi ba trang thai la hpp hpp krm ehua tdi, tdi eai thien va tdi dat dp Cling cao. \-di su bien ddi eua Ue (dien ap danh lira).
May cat da}- de thu nghiem la may CW322S, day eat ddng, thiet bi do la ddng hd so. Ket qua thu dupc nhu sau:
Danh gia chieu rdng eua ranh cat Al tren phdi, ta
(*) Khoa Supham Ky thuat, Dai hgc Bach khoa Ha Noi (**) Cong ty TNHH Cong nghiep Quang Nam
dimg phuang phap do kiem la: - Sau khi gia edng mau xong, ta tien hanh do kich thudc ben trong va kich thude ngoai cua ldi, chieu rdng ranh cat thue te se dupe tinh theo cdng thire:
+ Ddi vdi kich thude thang
Al. xlOOO
+ Ddi vdi kich thudc Id
A/ D-d xlOOO- Dung eu do la ma}- do tao dp 3 chieu C544, cd dp chinh xac ed 0,1pm.
Nghien ciru anh hudng don eua eae thdng sd cdng nghe U ; I ; t den chieu rdng ranh cat Al, ta thuc hien eat lan lupt eae mau tir 1 den 12 bang each cho mdt thdng sd tha} ddi, cdn cac thdng sd khae giir cd dinh. Lam chi nghiem vdi 3 trang thai vat lieu tuang irng vdi hai bien dang gia cdng la hinh chij- nhat ed kich thudc 20 x 10 mm va dudng trdn cd ban kinh la R5, ta thu dupe bang ket qua va cac dd thi bieu dien mdi quan he anh hudng cua timg thdng sd den chieu rdng khe hd nhu sau:
Hinh 1: So do gia cong mau thi nghiem
TAP CHI c a KHl VIET NAM V So 1+2-Tliang 1+2 nam 2011
NGHIEN cuu-TRAOOOI
Anh hudng cua dien ap phdng dien Ui den chieu rdng rarih eat, do theo chieu dai Id hinh chir nhat.
Al (nm) ' ^
3'?a
r?in 305
4.5 50 5 5 fin fi5 70 Ui (V) Hinh 2: Anh huong ciia dien ap phong dien U^ den chieu rong ranh cat, do theo chieu dai 16 hinh chii nhat
• Anh hudng cua dien ap phdng dien Ui den chieu rdng ranh cat, do theo chieu rdng Id hinh chii nhat.
Al(nm) il
334 332 330 328 326 324 322 320 318 316 314
45 50 55 60 65 70 U (V)
Hinh 3. Anh huong ciia dien ap phong dien Ui den chieu rong ranh cat, do theo chieu dai 16 hinh chii nhatAnh hudng ciia ddng phdng tia lira dien I^ den chieu rdng ranh cat, do theo chieu dai Id hinh chir nhat.
A1 (|im)
338 336 334 332 330 328 326 324
1.5 2 2.5 3 3.5 4 4.5 Ie (A)
Hinh 4: Anh huong cua dong phong tia lua dien I^ dSn chieu rong ranh cat, do theo chiSu dai 16 hmh chii nhat C^
TAP CHI c a KHI VIET NAM V So 1+2 - Thang 1+2 nam 2011
NGHIEN CUU - TRAO OOI
Anh huong eua ddng phdng tia lua dien I^ den khe hd theo chieu rdng lo hmh chir nhat.
Al (nm) 3 4 0 3 3 8 336 3 3 4 3 3 2 330 328 326 3 2 4 3 2 2
1.5 2 2.5 3 3.5 4 4.5
ITinh 5: Anh huong cua dong phong tia lua dien I^ d6n chi6u rong ranh cat, do theo chieu rong 16 hinh chfi' nhat
- Anh hudng cua thdi gian ngimg phdng tia lira dien t^ den chieu rdng ranh ck, do theo chieu dai Io hinh chii- nhat.
A l ((am) 3 1 9 3 1 8 3 1 7 3 1 6 3 1 5 3 1 4 3 1 3 3 1 2 3 1 1 3 1 Q
- 3 0 3 5 4 0 4 5 5 0 5 5 t o ( | - i s )
Hinh 6: Anh huong cua thai gian ngimg phong tia lira dien t den chieu rgng ranh cat, do theo chieu dai 16 hinh chii nhat
- Anh hudng cua thdi gian ngirng phdng tia lira dien t^ den chieu rdng ranh cat, do theo chieu rdng Id hinh chil- nhat.
A L ((.im) . 321 3 2 0 3 1 9 3 1 8 3 1 7 3 1 6 3 1 5 3 1 4 3 1 3 3 1 2
3 0 3 5 4 0 4 5 5 0 5 5 to (|j.s)
Hinli 7 : Anh huong cua tho-i gian ngimg phdng tia lua dien t^ den chieu rong ranh cit, do theo chi6u rong 16 hinh chii nhat.
Ket luan:
- Khi tang gia tri dien ap U_ trong mien dien ap ciia may thi chieu rdng ranh cat eiing tang theo, mirc dd tang gan nhu tu} en tinh.
- Khi tang gia tri ddng phdng tia lua dien I^ thi chieu rdng ranh cat eiing tang theo nhung vdi qui luat ham phi tu}'en.
- Khi tang gia tri dien ap t^ trong mien dien ap cua ma}- thi chieu rdng ranh eat ciing tang theo, mirc dp tang la tuyen tinh.
De cd chieu rdng ranh cat la nhd, ta dua cac thdng sd dien ve gan gia tn gde. •••
Tai lieu tham khao:
[1] Nguyen Trgng Binh: "Toi uu hoa qua trinh gia cong cat got »; NXB (iiao due, Ha Noi, 2003.
[2] Ko-Ta Chiang, Fu-Pmg Chang,"Optmiizahon of the WEDM process of particle-remforced material -with multiple performance characteristics usmg grey relational analysis", .Toumal of Materials Processmg Technology, Volume 180, 1 December 2006.
[3] S. Sarkar, S. Mitra, B. Bhattacharyya; "Parametric analysis and optunization of wire electncal discharge machining of Y-titanium alummide alloy"; Joumal of Materials Processing Technology, Volume 159, Issue 3, 10 February- 2005, pages 286-294.
[4] Mustafa I llianGokler/LlpMithatOzanozgii; "Experimental investigation of effects of cuttmg parameters on surface roughness in the -WEDM process"; Intemational Joumal of Machme Tools and Manufacture. Volume 40, Issue 13, October 2000.
TAP CHI c a KHi VIET NAM V So 1+2 - Thang 1+2 nam 2011
