Turning control apparatus

Abstract

A turning control apparatus includes a turning body and a hydraulic motor to turn the turning body. A high-pressure relief circuit relieves hydraulic pressure of a first hydraulic line at a first relief pressure, the first hydraulic line supplying an operating oil to drive the hydraulic motor. A hunting reduction circuit relieves a hydraulic pressure of a second hydraulic line at a pressure lower than the first relief pressure, the second hydraulic line being connected to a deceleration-side hydraulic port from which the operating oil is discharged when the hydraulic motor is being driven. The hunting reduction circuit connected to the deceleration-side hydraulic port is caused to open before an operation lever to operate turning of the turning body returns to a neutral position.

Dependencies are inferred from the claim text.