Interior outer piston auto -lock cylinder

The utility model discloses an interior outer piston auto -lock cylinder, comprising a cylinder body, the cylinder body both ends are fixedly connected with protecgulum and hou gai respectively, the cylinder body includes internal cylinder sleeve and outer cylinder bushing, internal cylinder sleeve is equipped with inner piston and piston rod, the piston rod stretches into internal cylinder sleevefrom the protecgulum, and piston rod and inner piston fixed connection, be equipped with the venthole with external intercommunication with internal cylinder sleeve on the protecgulum, be equipped with outer piston and hydraulic oil in the outer cylinder bushing, be equipped with the inlet port with the outer piston intercommunication on the protecgulum, after cover the connecting hole that is equipped with hydraulic oil and internal cylinder sleeve intercommunication, be equipped with the holding chamber with the venthole intercommunication on the protecgulum, holding intracavity brake locksubassembly, the brake loc