System for controlling the supply of hydraulic fluid to a work vehicle implement

A system for controlling the supply of hydraulic fluid to an implement of a work vehicle, the implement including a hydraulic cylinder having a first chamber and a second chamber, the system comprising:

• a pump configured to provide hydraulic fluid under pressure through a pump output line;
• a control valve in flow communication with the pump output line, the control valve being configured to regulate a supply of hydraulic fluid to the hydraulic cylinder, wherein the control valve is adjustable between a raise position, a lower position and a modified float position;
• a first fluid line provided in flow communication with a first output port of the control valve, the control valve being configured supply hydraulic fluid through the first fluid line to the first chamber of the hydraulic cylinder for raising at least one ground-engaging component of the implement relative to the ground;
• a second fluid line provided in flow communication with a second output port of the control valve, the control valve being configured to supply hydraulic fluid through the second fluid line to the second chamber of the hydraulic cylinder for lowering the at least one ground-engaging component relative to the ground;
• a pressure control valve provided in flow communication with the second fluid line, the pressure control valve being configured to regulate a fluid pressure of the hydraulic fluid being supplied to the second chamber of the hydraulic cylinder;
• a bypass fluid line configured to provide a flow path for hydraulic fluid between the pump and the second fluid line that is independent of the control valve;
• a bypass valve provided in flow communication with the bypass fluid line, the bypass valve being configured to cut-off the flow path defined by the bypass fluid line when hydraulic fluid is being supplied from the control valve through the first fluid line to raise the at least one ground-engaging component relative to the ground;
• and
• a load sensing line configured to provide an indication of the fluid pressure of the hydraulic fluid being supplied to the second chamber of the hydraulic cylinder from the pressure control valve, wherein, when hydraulic fluid is being supplied through the pressure control valve from the pump, operation of the pump is configured to be controlled based at least in part on the fluid pressure of the hydraulic fluid being supplied to the second chamber of the hydraulic cylinder, wherein the load sensing line is coupled between a load sensing controller of the pump and a portion of the second fluid line extending between the pressure control valve and the second chamber of the hydraulic piston, the load sensing controller being configured to adjust an output pressure of the pump;
• wherein, when in the control valve is in the modified float position, hydraulic fluid is directed between the pump and the pressure control valve via the bypass fluid line, the pressure control valve being configured to maintain the fluid pressure of the hydraulic fluid supplied to the second chamber of the hydraulic cylinder substantially constant based on an operator-selected pressure value.