Auto-lock hydraulic hoist cylinder device and control method thereof

An auto-lock hydraulic hoist cylinder device, comprising:

• a lock actuator (1), a lock transmission mechanism (2) and a load-bearing mechanism (3), wherein said load-bearing mechanism includes a load-bearing locking shaft (301), a load-bearing nut (302) is provided on said load-bearing locking shaft (301), installed on the upper side of an upper end cover (502) of a main hydraulic hoist (5), a number of protrusions (303) are provided on the lower end of said load-bearing locking shaft (301), a locking cover (304) is provided with a through hole for said load-bearing locking shaft (301) to pass through, a groove (305) for matching said protrusions (303) is provided on the side wall of the through hole, a piston rod (506) is fixed with the lower end of said locking cover (304), said lock actuator (1) is provided on said upper end cover (502), and drives said load-bearing locking shaft (301) via said lock transmission mechanism (2).