When the control lever is moved to “DOWN” position, the spool (1) is pushed into the position control
valve body as shown in the figure.
Since the spool (1) blocks the oil entering to A chamber (a), pressured oil from P port opens the unload
poppet (2) and drains to T1 port.
The oil remaining in the A chamber (a) returns to the transmission case through the clearance between spool
(1) and the control valve body.
Since the poppet 2 (4) is pushed by the plate (5) connected to the spool (1), the oil circuit between C port and T2 port is formed.
The oil in the hydraulic cylinder is forced out by the weight of the implement, and returns to the transmission
case through T2 port, lowering the implement.
<Floating>
When the control lever is moved all the way to the bottom, the spool (1) and the poppet 2 (4) remain in the positions described for “Lowering”. The oil flows freely between the hydraulic cylinder and the transmission case.
