Patent ID: 9618018
Date: 2017-04-11
CPC Classifications: E02F,F15B

Claim:
1. A hydraulic system for construction equipment, comprising: a pump/motor serving as both pump and motor; an actuator provided with a first port and a second port, and operated by a working fluid provided from the pump/motor; a first hydraulic line and a second hydraulic line connected with the first port and the pump/motor; a third hydraulic line and a fourth hydraulic line connected with the second port and the pump/motor; a first logic valve disposed in the first hydraulic line and the second hydraulic line; and a second logic valve ( wherein when a first pressure of a higher pressure side between the first port and the second port is larger than a second pressure of the pump/motor, the pump/motor is operated from a time point, at which an operating unit is operated, so that the first pressure and the second pressure are controlled to be the same before the first and second logic valves are opened.