Patent ID: 9115702
Filing Date: 2015-08-25
Classification: E02F,F04B,F15B

Abstract:
1. Hydraulic system comprising: a source of high pressure (A), a consumer (C) connectable to the source of high pressure (A) via a flow control valve, and a solenoid valve arranged to control the flow control valve, wherein the hydraulic system further comprises: a hydraulic pilot valve that is selectively controllable by the solenoid valve to connect a control chamber in the flow control valve either to the source of high pressure (A) or to a low pressure side (T), wherein the hydraulic pilot valve is configured so that when the solenoid valve is in its first position, the source of high pressure (A) is arranged to act on a first end of the hydraulic pilot valve to hold the hydraulic pilot valve in a first position wherein the control chamber is connected to the source of high pressure (A) and the flow control valve prevents flow from the source of high pressure (A) to the consumer (C), wherein the hydraulic pilot valve is configured so that when the solenoid valve is in its second position, the solenoid valve is arranged to connect the source of high pressure (A) to the consumer (C) via a by-pass conduit in order to pre-pressurize the consumer (C) prior to the opening of the flow control valve; and wherein the source of high pressure (A) is arranged to act on the first end and on a second end of the hydraulic pilot valve wherein a spring acting on the second side is arranged to displace the hydraulic pilot valve into a second position in which the control chamber is connected to the low pressure side (T) and the flow control valve is opened.