Pressure maintaining apparatus, machine tool, and method of running pressure maintaining apparatus in machine tool

Abstract

A machine tool includes: a plurality of hydraulic devices including hydraulic balance cylinders; a main hydraulic unit including a main hydraulic pump and a pump motor for supplying hydraulic oil in an operation period; and a pressure-maintaining hydraulic unit connected in parallel to an oil supply line of the main hydraulic unit and including a pressure-maintaining hydraulic pump and a pump motor being smaller in output than the main hydraulic pump and the pump motor. When at least one of the hydraulic devices is operated, the hydraulic oil is supplied from the main hydraulic pump and the pump motor to the hydraulic devices. When all of the hydraulic devices are stopped, the hydraulic oil is supplied from the pressure-maintaining hydraulic pump and the pump motor to the hydraulic device in the standby period to maintain the pressure of the hydraulic oil in the hydraulic device.

Description

technical field [0001] The present invention relates to a pressure maintaining device for maintaining hydraulic pressure during standby, a machine tool, and a method for operating the pressure maintaining device of the machine tool. Background technique [0002] Figure 5 Indicates a portal machine tool. The portal machine tool 10 (hereinafter referred to as the machine tool 10 ) has: a bed 11 installed on the floor; a table 12 on which a workpiece (workpiece) is placed; and two columns 13L, 13R erected on the left and right sides of the bed 11 the horizontal guide rail 14 provided movably in the vertical direction along the vertical sliding surface of the columns 13L, 13R; the saddle provided movably in the horizontal direction along the horizontal sliding surface of the horizontal guide rail 14 15. A ram 16 and the like provided movably in the vertical direction guided by the vertical sliding surface of the saddle 15 . In addition, reference numerals 17L and 17R denote f...

AI Technical Summary

Problems solved by technology

[0010] In this way, although the accumulators 51L, 51R are provided adjacent to the hydraulic balance cylinders 18L, 18R, it is difficult to avoid oil leakage from the hydraulic balance cylinders 18L, 18R as the axis of gravity, and pressure retention in the accumulators 51L, 51R is difficult. After the capacity drops, the main hydraulic unit 20 needs to be operated again to maintain the pressure. There is still room for improvement in terms of power consumption reduction and energy saving during standby.

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