Regenerative hydraulic circuit for dump truck bin lift cylinder

摘要

An articulated dump truck is provided with an electro-hydraulic bin control system including a proportional control valve for the bin lift cylinders and including a solenoid-operated regenerative valve assembly mounted adjacent the lift cylinders and being actuated, during lifting the bin for dumping a load of material from the bin, to cause a regenerative flow to occur when the force required by the bin lift cylinders to continue lifting the bin falls to a predetermined force. The force required for tilting the bin is continuously calculated by an electronic control unit taking into account a sensed bin load, a sensed bin tip amount and a sensed side-to-side inclination of the bin. In a simplified second embodiment, the proportional control valve controls the regenerative flow.

主权项

1. An electro-hydraulic control system for controlling an operation of at least one hydraulic lift cylinder coupled for tipping a loaded bin upwardly about a pivot axis for dumping a load from the bin, the control system comprising: a source of pressure fluid; a fluid tank; a control valve arrangement coupled for controlling the flow of pressure fluid to, and return fluid from, said at least one lift cylinder and including a regenerative flow control arrangement responsive to a regenerative flow signal for coupling the rod end of the at least one hydraulic lift cylinder to the head end when the cylinder force required to continue movement of the bin to a fully dumped position decreases to a preselected cylinder force which is substantially less than an initial cylinder force required for lifting said bin at a beginning of a dumping operation; an electronic control unit including a memory containing a stored predetermined bin condition value including a bin tip angle corresponding to when said cylinder force requirement is equal to said preselected cylinder force; and a bin condition sensor arrangement being operative to sense the bin tip angle and to provide to said control unit with a tip angle signal representing a sensed bin tip angle and a weight signal representing a sensed weight of material in the bin, said control unit comparing said sensed tip angle signal with said stored predetermined bin condition value that includes said bin tip angle, with said control unit sending said regenerative flow signal to said control valve arrangement for causing said regenerative flow through said regenerative flow control arrangement in response to the sensed bin condition signal equaling said stored predetermined bin condition value.