lua chon may xuc mot gau cho thi cong

Khi dao va van chuyen dat vao o to de cho di xa, ta co hai hinh thuc thi cong: 

- Neu chieu rong ho dao khong lon (khong vuot qua ban kinh dao cho phep cua may xuc) ta se co hinh thuc dao ngang, nghia la huong di chuyen may dao song song voi ho dao. 

- Neu chieu rong ho dao lon va thuan tien de o to vao lay dat ca hai phia thi ta co hinh thuc dao doi dinh, nghia la may xuc vua dao vua lui doc theo ho dao. 

Doi voi may dao gau day 

May dao gau day co ban kinh lam viec tuong doi lon nen no co the truc tiep dao roi do dat vao nen dap, hoac do dat thanh dong. No thich hop dung de nao vet bun, khai thong song, ngoi, muong ranh. Noi chung thi cong voi dat mem, uot thi may dao gau day co nang suat cao. Chieu sau dao khong nen vuot qua 50% chieu dai can. 

Tuy theo dia hinh thi cong va dieu kien dat dai ma co cac so do lam viec cua may dao khac nhau. 

Thi du, voi dieu kien o to khong the dung duoi ho dao de lay dat duoc, ta co so do thi cong nhu (hinh 3-11). 

Tren so do nay, ta thay truc dao cua may xuc luon luon song song voi truc duong o to dung lay dat. Vi tri dung cua o to lam sao cho goc quay do cua may dao la nho nhat, de giam thoi gian chu ky lam viec cua may dao, dong thoi de dam bao an toan trong khi may dao quay do dat vao thung o to, thi nen cho thung o to huong vao phia quay can do cua may dao. Cac kich thuoc cua khoang dao se tuy thuoc vao tung loai may dao va o to. 

Truong hop o to co the dung duoi ho dao de lay dat, khi do vi tri dung cua may xuc cao hon han o to thi ap dung so do dao con thoi (hinh 3-12). 

Voi so do dao nay, goc quay do cua may dao la nho va may dao co kha nang lam viec lien tuc khong phai cho doi o to. Cach thi cong nhu kieu nay dam bao nang suat cao. Tuy nhien no co nhuoc diem la phai lam duong cho o to len xuong ho dao de dang.

d- Nhung bien phap nang cao nang suat may dao mot gau 

- Cong thuc tinh nang suat dao mot gau: 

(3.1)  

trong do: N- nang suat cua may dao lam viec trong 1 gio 

q- dung tich gau, m3; tck - thoi gian mot chu ki lam viec, s; 

kd¬- he so day gau (la ty so giua the tich dat da thuc te xuc duoc day gau va the tich hinh hoc cua gau); 

kx- he so toi xop cua dat; 

ktg- he so su dung thoi gian; doi voi may dao thuong lay ktg= 0,20,25, cac he so kd¬ va kx co the lay theo bang duoi day: 

- Cac bien phap nang cao nang suat may xuc mot gau 

Hien nay o nuoc ta co rat nhieu loai may dao mot gau dang thi cong o nhieu cong truong vao cac cong viec khac nhau nhu: khai thac da, khai thac quang than, dao dat, v.v... Da co nhung don vi, ca nhan su dung may dao dat duoc nang suat cao, kinh nghiem nay chua duoc pho bien rong rai nen cung con nhieu noi nang suat lam viec cua may dao van thap (thuong hut chi tieu dinh muc). Nguyen nhan cua viec dat duoc nang suat cao phu thuoc rat nhieu yeu to, sau day la nhung yeu to anh huong den nang suat va bien phap nham nang cao nang suat cua no. 

+ Nguoi cong nhan phai biet su dung thanh thao may, rut ngan chu ky lam viec bang cach ket hop cac thao tac mot cach toi da. 

Thi du, trong khi cho may dao do dat da vao o to co the phoi hop them cac dong tac: keo tay gau ve phia may dao; nang gau len do cao can thiet de chuan bi do; dua tay gau ra phia ngoai truoc khi do; ha gau xuong vi tri can do; do dat, da khoi gau. 

Khi quay may dao lai phia via dao co the phoi hop cac dong tac: keo tay gau lai phia buong lai; ha gau xuong de bat dau dao; do dat da ra khoi gau.  

+ Chon phuong tien van chuyen tot, phu hop voi dung tich gau. Ty le giua dung tich gau may dao va dung tich thung xe o to la mot yeu to quan trong anh huong toi nang suat may. 

Thi du, may dao CE-3 khi dung tich cua phuong tien van chuyen voi dung tich gau la 1:1 thi nang suat may dao chi dat 60% so voi may dao do vao phuong tien van chuyen co dung tich thung chua gap 8 lan dung tich gau dao. Thong thuong chon phuong tien van chuyen phuc vu may dao nen chon loai thung chua lon hon dung tich gau tu 4 den 5 lan. 

+ Lap kich thuoc khoang dao hop ly (xem bang chieu cao dao hop ly cua mot so loai may dao), va cho dung cua cac phuong tien van chuyen chinh xac, sao cho goc quay trung binh cua may la nho nhat va hieu suat cua no lon nhat. 

+ To chuc tot cac phuong tien van chuyen lam sao duoc lien tuc, khong de xay ra truong hop may dao phai cho o to. 

+ Chuan bi cho dung lam viec duoc thuan loi, tranh go ghe va doc nghieng. Khi khai thac da, quang phai duoc lam toi, xop bang phuong phap no min.