Single-acting pin-type telescoping arm, telescoping method thereof, and crane having the telescoping arm

摘要

A single-acting pin-type telescoping arm, a crane, and a telescoping method thereof. The single-acting pin-type telescoping arm has a basic arm (11) and at least one section of telescoping arm (12, 13, 14, 15, 16) sleeved inside the basic arm (11). A coaxial central hole is disposed at an end portion of the telescoping arm (12, 13, 14, 15, 16). A telescoping cylinder is disposed in the central hole. The telescoping cylinder comprises a piston rod and a cylinder barrel (17). At least 2 cylinder heads (18, 19) are fixedly sleeved longitudinally on an outer side of the cylinder barrel (17). At least 3 arm pinholes (23, 24, 25) are disposed longitudinally on both the basic arm (11) and the telescoping arm (12, 13, 14, 15, 16). The single-acting pin-type telescoping arm uses one telescoping cylinder and at least 2 cylinder heads (18, 19), where each cylinder head (18, 19) can implement locking and unlocking between the telescoping cylinder and any telescoping arm (12, 13, 14, 15, 16), and perform extension or retraction of the telescoping arm (12, 13, 14, 15, 16) in a relay transmission manner to implement telescoping of the single-acting pin-type telescoping arm, thereby shortening the cylinder, reducing a cylinder diameter and a rod diameter of the cylinder, lowering a cost of the cylinder, reducing an onboard weight, enhancing a hoisting capability, and providing higher flexibility for the design of a crane.