TRUING DAI HQC SU PHAM KY THU AT
THANH PHO HO CHI MINH
K H OA C O K HI C H E T A O M A Y
BQ M O N C O SCf T H IE T K E M A Y
DE THI CUOI KY HQC KY I NAM HQC 2023-2024
Mon: NGUYEN LY - CHI TIET MAY
Ma mon hoc: MMCD230323
D6 so/Ma de: CLC-HK1-2324 Be thi co 02 trang.
Thai gian: 90 phut. Ngay thi: 27/12/2023
Sinh vien duac phep su dung 1 ta A4 viet tay.
Bo truyen
'dai thang
Hinlt 1: Sa do dan dong
Cau 1 (3 diem):
Cho he thong dan dong ca khi co sa do dong
duac mo ta nhu Hinh 1. Cac so lieu cho trudc
bao gom:
- Bo truyen dai thang co cac thong so: d i=90
mm; d2= 180 mm va a = 400 mm.
- Bo truyen banh rang tru rang nghieng tieu
chuan co so rang Z/=24; Z;=78; va mo dun
phap mn = 2 mm.
- Bo truyen true vit - banh vit tieu chuan co:
Z?=2; Z^=44; he so duong kinh q = 8 mm; mo
dun m =4 va hieu suat r/34 = 0,78.
- Gia su hieu suat truyen dong cua cac cac 6 lan
va bo truyen banh rang bang 7=1.
- Tang quan cap co ducmg kxnh D = 500 mm.
Trong luong vat nang Q = 4200 N.
a) Tinh goc ai va kiem tra dieu kien goc om; (0,5 d)
b) Xac dinh goc nghieng /? cua bo truyen banh tru rang nghieng de thoa di6u kien a 12= 0 3 4 ; (0,5d)
c) Xac dinh phuang, chieu cac luc tac dung len true vit, banh vit trong truong hap nang vat; (0,75d)
d) Xac dinh do Ion cua cac luc tac dung (Ft; Fr va Fa) len banh rang trong bo truyen banh tru rang
nghieng. (l,25d)
Cau 2 (2,0 diem): Cho he banh rang nhu Hinh 2. So rang cua cac banh rang trong he lan luat la:
2, Z/= Z4=25; Zg= 50; Zj=75; Zj= 20; Z<s= 120. T6c do quay cua true banh
rang Zi la n/= 1450 (Vong/phuQ. Hay tinh
a) Bac tu do cua he banh rang da cho; (0,5 d)
b) Xac dinh chieu quay va toe do cua can C (so vai banh rang Z/). (1,5 d)
Cau 3 (3,0 diem): True trung gian cua he thong truyen dong ca khi gom
cac luc tac dong co chieu nhu Hinh 3. Cac luc an khop: Fn = 1111,1 N;
Fri = 404 N ; Fa = 460 N; Fr 2 = 173 N va Fa 2 = 123 N. Duong kinh vong
chia cua cac banh rang lan luot la di = 90 mm va 6/2= 217,4 mm. True
dugc che tao bang thep co ung suat uon cho phep [ <j f ] = 50 MPa.
Biet chieu dai cac doan true Li = L2 = L3 = 100 mm
a) Xac dinh phuang, chi6u va do lan cua cac phan luc tai cac g6i B,D-,( 1 d)
b) Ve cac bi6u d6 noi lire momen uon Mx, My, momen xoan T va ghi gia tri cac momen tai
cac tiet dien nguy hiem; (1,25 d)
? o
- T
TO ^2
1 ^
can c
^3 2
- z0
T .
Hinh 02: He banh rang
So hieu: BM1/QT-PDBCL-RBTV
c) Xac djnh duong kinh true tai vi tri lap 6 lan (tai vi trf B) theo thuydt ben 4. (0,75 d)
Cau 4 (2,0 diem): Xet moi ghep lien ket cac chi tiet may 1 va 2 bang nhom 4 bu-long co cac thong
so hinh hoc, chiu cac tai Fv F2 nhu mo ta tren Hinlt 4. Gia su moi ghep bu-long lap co khe ho, cho
truoc Fi = 2200 N; F2 = 1000 N; he so ma sat/ = 0,2; he so an toan k = 1,5; Li = 700 mm; L2 = 400
mm; D = 250 mm; ung suat keo cho phep cua bulong [o>] = 100 MPa.
a) Phan tich tai tuong duong quy ve tarn cua cac bu-long, xac dinh vi tri bu-long mang tai tuong
duong Ion nhat, tinh gia tri tai tuong duong Ion nhat; (1,0 d)
b) Tinh lyc xiet V can thiet de nhom bu-long co the chiu duoc tai Fv F2 da cho, xac dinh duong
kinh bulong (di, duong kinh chan ren) theo dieu kien ben ung su&t phap voi he s6 an toan k, su dung
bang thong so bu-long de chon bu-long tieu chuan phu hop. (1,0 d)
Bulong M6 M8 M10 M12 M16 M20 M24 M30 M36
di, mm 4,917 6,647 8,376 10,106 13,835 17,294 20,752 26,211 31,670
Chuan dau ra cua hoc phan (ve kien thirc) Noi dung
kiem tra
[G1.2]: Co kien thuc trong tinh toan thiet ke chi tiet may va may Cau 4
[G2.3]: Thanh thao trong giai quyet cac bai toan ve phan tich lure tac dung len
chi tiet may, co cau may Cau 1
[G 2.2]: NSm virng co so tinh toan thiet ke cac chi tiet may: cac thong so co ban,
cac dac diem trong truyen dong, ti so truyen, van toe, hieu suat Cau 2
[G4.1]: Hieu dupe cac chi tieu tinh toan doi voi timg chi tiet may noi chung, tir
do nim virng dupe trinh tu tinh toan thiet ke cac he truyen dong co khi va cac
lien ket trong may.
Cau 3
TP HCM ngay 25 thang 12 nam 2023
Truong nganh
______
TS. Truong Quang Tri
S6 hieu: BM1/QT-PDBCL-RDTV