| 摘要 |
In a reciprocating slat conveyor, at least three slat sets of at least one slat (CS) each are driven by piston-cylinder drive units (26), one for each slat set. Each drive unit (26) is provided with a four-way proportional directional control (PDC) valve. Each PDC valve has a first position of adjustment in which it connects a first working chamber of its drive unit (26) to pressure (B) and a second working chamber to tank (T), and a second position of adjustment in which it connects the second working chamber to pressure (P) and the first working chamber to tank (T). Control logic (96) provides electrical control signals for directing the PDC valves to operate the drive units to advance more than half of the slat sets simultaneously in a first, conveying direction, and to retract the remaining slat sets in the opposite direction at a higher rate of speed. A controller compares the control logic signals with feedback signals generated by a separate linear position sensor PS for each slat set. The controller compares the desired positions of the slat sets, as determined by the control logic (96), with the actual positions of the slat sets, as determined by the position sensors PS. The difference between the desired and actual positions of the slat sets is used to generate a corrected control signal which the controller sends to proportional amplifiers (PA). The proportional amplifiers (PA) provide control signals to the PDC valves, for changing the rate of hydraulic fluid movement into and out from the working chambers of the drive units (26) for the advancing conveyor slat sets, towards establishing the desired pattern of movement of the slat sets. The conveyor includes a drive module comprising a pair of longitudinally spaced apart end frame members, each extending transversely of the conveyor, and a center frame member positioned longitudinally between the two end frame members, and also extending transversely of the conveyor. |
