4. Cong dung, phan loai, cau tao va nguyen li lam viec cua can truc thap xay dung.
1. Cong dung va phan loai
a. Cong dung: Can truc thap duoc dung rat pho bien de van chuyen vat lieu va lap rap cac cau kien trong xay dung dan dung, xay dung cong nghiep, xay dung thuy dien
b. Phan loai
- Theo dang thap co can truc thap voi thap quay va can truc thap co dau quay.
- Theo phuong phap thay doi tam voi cua can co can truc thap co can nang ha va can truc thap co can nam ngang (xe con di chuyen doc can).
- Theo phuong phap lap dat tren cong truong co can truc thap di chuyen tren ray, can truc thap co dinh va can truc tu nang.
- Theo cong dung co can truc thap cong dung chung dung trong xay dung dan dung va cong nghiep, can truc thap chuyen dung xay nha cao tang va can truc thap chuyen dung xay dung cac cong trinh cong nghiep.
2. Cau tao cua mot so can truc thap thong dung
Can truc thap thuong co thap cao tu 30 den 75m. Phia tren gan dinh thap co gan can dai tu 12 den 70m bang chot ban le. Mot dau con lai duoc treo bang cap hoac thanh keo di qua dinh thap. Ket cau chung cua mot can truc thap thuong gom hai phan: phan quay va phan khong quay. Tren phan quay co bo tri cac co cau cong tac nhu: toi nang vat, toi nang can, toi keo xe con, co cau quay, doi trong, trang thiet bi dien va cac thiet bi an toan. Phan khong quay co the duoc dat co dinh tren nen hoac co kha nang di chuyen tren duong ray nho co cau di chuyen. Tat ca cac co cau cua can truc deu duoc dieu khien tu cabin treo o tren cao gan dinh thap. Can truc thap thuong co suc nang tu 1 den 12tan. Momen tai co the dat den 350t.m, tam voi tu 8 den 50m, chieu cao nang den 100m, toc do nang thay doi trong mot khoang rong tu 0,3 den 2m/s, toc do ha vat khi lap rap co the dat thap toi 0,08m/s, toc do quay tu 0,3 den 1v/ph, thoi gian thay doi tam voi tu 25 den 100s, toc do di chuyen xe con tu 0,2 den 1m/s, toc do di chuyen can truc tu 0,2 den 0,6m/s .
a. Can truc thap loai thap quay. Can truc loai nay thuong su dung phuong phap thay doi tam voi bang cach nang ha can. Cau tao chung duoc the hien tren hinh 1.12. Hinh 1.12. Can truc thap loai thap quay
a. Cau tao chung; b. Khung di chuyen can truc
1- Khung di chuyen; 2- Co cau di chuyen; 3- San quay; 4- Thiet bi tua quay; 5- Thap; 6- Doi trong; 7- Co cau nang vat; 8- Co cau nang can; 9- Can; 10- Khop ban le tai chan can; 11- Cap neo; 12- Puly doi huong cap; 13- Palang nang ha can; 14- Thanh giang; 15- Cap nang vat; 16- He thong thanh giang.
Can truc gom khung di chuyen 1 di chuyen duoc tren ray nho co cau di chuyen 2. San quay 3 tua tren thiet bi tua quay 4 va quay xung quanh truc quay cua can truc nho co cau quay dat tren san quay. Tren san quay co lap thap 5, doi trong 6, co cau nang vat 7, co cau nang can 8 va thiet bi dien. Can 9 duoc noi mot dau voi than thap thong qua khop ban le 10, dau con lai duoc treo boi cap neo 11 vong qua cum puly doi huong 12 lap tren dinh thap. Cap neo duoc noi voi cum puly di dong cua palang nang ha can 13. Cum puly co dinh cua palang nang ha can duoc neo voi san quay nho he thong thanh giang 14. Vat nang duoc nang, ha nho cap nang vat 15 vong qua dinh thap va di xuong co cau nang vat dat o san quay. Thap dung duoc dat tren san quay nho chot ban le va he thong thanh giang 16. Thap co cau tao tu thep goc hoac thep ong han lai thanh gian, voi tiet dien ngang than thap la hinh vuong. Thap thuong duoc cau tao bang nhieu doan dang cac modun va lien ket voi nhau bang bulong.
De can truc chuyen dong duoc tren doan duong vong, cac cum goi tua cua khung di chuyen co cau tao dam bao lac duoc quanh truc dung. Moi cum goi tua co tu mot den hai banh xe. Cac cum goi tua nay khong gan cung voi khung di chuyen ma thong qua bon chan tua. Cac chan tua nay cung co kha nang lac duoc quanh truc dung. Cac chan tua nay co kha nang gap lai duoc nen co the thu nho duoc kich thuoc chieu ngang khi van chuyen may tren duuong. De dam bao an toan, giua cac chan tua nay duoc lien ket voi nhau bang he thong thanh giang. Khi quay vong co the thao he thong thanh giang cho hai chan tua.
b. Can truc thap co dau quay (thap khong quay)
Cau tao can truc loai nay the hien tren hinh 1.13. Hinh 1.13. Can truc thap loai dau quay
1- Khung di chuyen; 2- Thanh chong xien; 3-Doan thap co so; 4-Doan thap tren; 5-Phan dau quay; 6- Co cau nang vat; 7- Doi trong; 8-Vong tua quay; 9-Xe con mang vat nang; 10-Toi keo xe con; 11,12-Cap neo; 13- Doi trong.
Bao gom khung di chuyen 1 tren do dat doan thap co so 3 duoc giu boi bon thanh chong xien 2. Khung xe co the di chuyen tren duong thang hoac duong vong nho hai co cau dan dong. Doan thap tren 4 duoc to hop tu cac doan thap ngan co tiet dien nho hon doan thap co so. Phan dau quay 5 gom dinh thap, can, can congxon duoc tua tren dau thap co dinh thong qua vong tua quay 8. Tren can congxon co lap dat doi trong 7 va co cau nang 6. Can va can congxon duoc lap voi san quay bang khop ban le o mot dau can, dau kia duoc neo giu boi cap neo 11 va 12. Cabin va co cau quay duoc bo tri tren san do lien ket truc tiep voi vong tua quay. Xe con mang vat nang 9 duoc di chuyen tren can nam ngang nho toi keo xe con 10. O hai phia dau can deu co co cau han che hanh trinh va u chan de han che duong di chuyen cua xe con. De dam bao on dinh cho toan bo can truc, tren khung di chuyen con bo tri doi trong 13.
c. Can truc thap xay nha cao tang. Khi xay dung cac nha cao tang nguoi ta thuong su dung can truc thap co dinh co dau quay, thap duoc neo vao cong trinh va theo chieu cao cua cong trinh, thap duoc noi them cac doan che tao san de tang chieu cao nang. Trong giai doan dau, khi cong trinh co do cao chua lon, co the dung can truc di chuyen tren ray, khi cong trinh da duoc xay cao, nguoi ta co dinh thap lai va neo vao cong trinh, thap tua tren be mong danh rieng cho can truc hoac mong cua cong trinh. Hinh 1.14. Can truc thap co dinh neo vao cong trinh.
a. So do cau tao; b.So do mac cap nang vat voi hai co cau dan dong; c. Phuong phap giang; d. So do mac cap lap dung. 1- Thanh giang; 2- Cot lap dung; 3- Ray truot; 4- Doan thap noi; 5,6- Co cau dan dong de nang ha vat; 7- Toi lap dung.
Tren hinh 1.14 la can truc thap co dinh, neo vao cong trinh va noi thap de tang chieu cao nang nho cot lap dung 2. Qua trinh noi thap duoc thuc hien nhu sau. Doan thap tren cung duoc co dinh voi cot lap dung 2 va thao cac lien ket giua doan thap tren cung voi phan thap duoi. Nang doan thap 4 can noi them len bang moc treo nho co cau nang cua can truc va treo vao ray truot 3. Dung toi lap dung 7 nang ca phan tren cua can truc len mot doan bang chieu dai cua doan thap can noi them 4 (cot lap dung truot tren phan thap phia duoi). Dua doan thap 4 vao khoang trong giua phan tren va duoi theo ray truot 3 va lien ket doan thap 4 voi ca phan tren va duoi cua thap. Cum puly phia tren cua palang lap dung duoc co dinh vao thap, con cum puly phia duoi co dinh vao dau duoi cua cot lap dung 2 va trong qua trinh lam viec chung dich chuyen len tren de nang toan bo phan tren cung cot lap dung len. Cot lap dung thuong duoc che tao dang dan bao quanh ba mat thap, de ho mat truoc de co the dua doan noi them vao. Cac can truc thap dang nay doi moi thay vi phai dung he thong palang cap lap dung nguoi ta thiet ke cac xylanh thuy luc de nang phan tren cua can truc.
BẠN ĐANG ĐỌC
