OVERLOAD PREVENTING DEVICE FOR CRANE OR TOWER CRANE

摘要

PURPOSE: To smoothly perform the grease coating operation by setting the maintenance inspection mode in addition to the normal operation mode determined by the allowable operating radius and limit load, and making the boom extension operation within the load curve region in the maintenance inspection mode larger than that in the normal operation mode. ;CONSTITUTION: A controller 38 is provided with an operation mode setter 64 setting the load curve determined by the suspension load and the maximum allowable operating radius corresponding to this suspension load and a maintenance inspection mode setter 66 setting the load curve determined by the maximum allowable operating radius corresponding to the empty load. The mode to be used can be switched by a mode selector switch 70 fitted to an operation panel in a operator's cab. The output from the selected one of the mode setters 64, 66 is inputted to a limit load calculation section 74, and the limit load is calculated from the actual operating radius value by an operating radius calculation section 60. The limit load is inputted to a load comparator 75 together with the output load from a suspension load calculation section 62, and an automatic stop signal generator 76 is activated by the compared result.;COPYRIGHT: (C)1995,JPO