BASE PUSHING DEVICE, SPEED CONTROLLER AND SPEED CONTROL METHOD OF SMALL-DIAMETER PIPE PROPULSION MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a base pushing device, a speed controller and a speed control method of a small-diameter pipe propulsion machine for shortening a whole work time with a simple structure by increasing a pumping rate of a variable displacement hydraulic pump to a maximum limit to accelerate a jack while driving an electric motor without overload when the jack is returned, even when the electric motor of small capacity and low power consumption is used for driving the variable displacement hydraulic pump.;SOLUTION: When the jack returns (S10), the pumping capacity is adjusted and determined (S14) by a pumping capacity control means to be maximum within a range where the electric motor does not exceed a rated capacity on the basis of information on pumping pressure (S12) from a pressure detecting means.;COPYRIGHT: (C)2004,JPO