| 摘要 |
<p>Disclosed are a fly jib luffing device, a crane and a fly jib luffing method. The fly jib luffing device comprises: a fixed truss boom (7A), a luffing truss boom (7B), and a luffing pulley mechanism (11), wherein the fixed truss boom (7A) is arranged at the head of a main boom of a crane, the luffing truss boom (7B) is hinged with the fixed truss boom (7A), and the luffing pulley mechanism (11) comprises a first pulley hinged with the fixed truss boom (7A) and a second pulley hinged with the luffing truss boom (7B). When the luffing pulley mechanism (11) is used to luff the fly jib (10), a luffing hoisting steel rope is wound around the luffing pulley mechanism (11). The technical solution uses the luffing pulley mechanism (11) combined with a main hoisting steel rope or an auxiliary hoisting steel rope which serves as the luffing steel rope to achieve automatic luffing of the working condition of the fly jib of the crane, saving time and energy without requiring additional electrical or hydraulic devices, and saving cost. In addition, the hoisting steel rope is pulled back simultaneously as the main boom is retracted so as to assist the retraction and decrease the pressure loading of an oil cylinder for retraction of the main boom.</p> |
