HYDRAULIC CONTROLLER

摘要

In a hydraulic controller, in order to easily provide a hydraulic back-up in the event of a failure of an electric system while maintaining a benefit of electrical control using a control unit (13) when controlling a displacement of a hydraulic pump (1) in accordance with a property of a hydraulic driving system, a pump regulator (16) is constructed such that the tilt theta of a swash plate (1a) increases as the pressure of a second oil pressure signal P.c decreases, the pump regulator is characterized in that a negative control pressure can be used instead of the second oil pressure signal, and the properties of a fixed throttle (10) and the pump regulator spring (18d) are set such that the pump regulator can be operated within an operation range of the negative control pressure. In a controlling unit (13), a negative control pressure Pc1 corrected in a block (102) is made to be a target value of the second oil pressure signal, a second electric signal E corresponding to the target value is obtained, and the operational range of a second oil pressure signal generated by a solenoid proportional valve (15) is made substantially equal to the negative control pressure.