HYDRAULIC CIRCUIT FOR SERIES AND PARALLEL DRIVING

摘要

PURPOSE: To convert from a series circuit to a parallel circuit when some of plural bolt connecting devices is completed to connect, and to operate the hydraulic motors separately. ;CONSTITUTION: When plural bolt connecting devices 2 to 4 are driven by using plural hydraulic motors 5 to 7, the rotations of the hydraulic motors are made the same so as to make the rotations of the belt connecting devices the same, and thereby, all the nuts advance in the connecting direction in the same manner depending on the leading of the screws. In order to realize such an operation, all the hydraulic motors are converted to a series circuit. On the other hand, at the finishing of the connection, it is difficult to finish all the connections of the bolt connecting devices simultaneously owing to the efficiency of the hydraulic motors, the screwing starting time of bolts and nuts, and the like. By making the hydraulic circuits in the series circuits in such a case, the load of the hydraulic motor to drive either a preceding nut runner is increased so as to increase the pressure of the hydraulic circuits, and by detecting that by a pressure sensor, the series circuit is released and converted to a parallel circuit.;COPYRIGHT: (C)1994,JPO&Japio