DRIVE CONTROL DEVICE OF WORK MACHINE

PROBLEM TO BE SOLVED: To enable the output of a power storage device to be set larger in the case that external charge is performed to a power storage device of a work machine in comparison with the case that the external charging is not performed.SOLUTION: A drive control device of a work machine includes: an assist motor 42 (motor-generator) for assisting driving of a pump 32 by an engine 31; a revolving motor 47 (motor-generator) for driving a revolving superstructure 3; means 52 for controlling output of a battery 41; and means 51 for detecting whether external charge is performed or not. When it is detected that external charge is performed, the means 52 does not limit the output of the battery 41 ( power storage device) when the assist motor 42 or the revolving motor 47 is driven, and performs control in a first mode for controlling on the basis of requests of the assist motor 42 and the revolving motor 47. When it is detected that external charge is not performed, the means 52 performs control in a second mode for maintaining an amount of remaining charge at a prescribed amount when the assist motor 42 or the revolving motor 47 is driven.