DEVICE FOR RESTRICTING VIBRATION OF BOOM IN HYDRAULIC WORKING MACHINE

PURPOSE:To restrict vibration of a boom by obtaining the rate of variation in pump pressure and feed-backing this rate to a flow-rate control device as a command of compensating flow-rate to the vibration of the boom. CONSTITUTION:A pressure intensifier 8 that detects pump pressure is connected to the discharge side of a variable delivery pump 4. The output from this pressure intensifier 8 is input into a differentiator 10 of a controller 9, and a differential quotient P' as a rate of variation in pump pressure is obtained by means of the differentiator 10. This differential quotient P' is multiplied by coefficient K, and this KP' is converted into oil pressure by means of a pressure intensifier 12. The oil pressure thus converted is feed-backed to a flow-rate control device 3. With this contrivance, the variation in pump pressure is read as the vibration information of a boom, and this information is added to the control element for controlling the flow-rate of the pump. Thus, the variation in pump pressure, or vibration of the boom can be restricted.