COVER AS-VALVE 2499504 - Caterpillar

Illustration 1 g00672142
Location of load control valve for the tilt cylinderHold Position
Illustration 2 g00672161
Load control valve for tilt cylinder in hold position (1) Check valve (2) Chamber (3) Port to head end of cylinder (4) Spool (5) Face (6) Port from double check valve (7) Plunger (8) Orifice (9) Port to rod end of tilt cylinder (10) Blocked oilIn the hold position, check valve (1) is seated by spring force. This blocks the oil in the head end of the cylinder and this maintains the selected angle of the work tool.Shock Load
Illustration 3 g00672209
Shock load (1) Check valve (2) Chamber (3) Port to head end of cylinder (4) Spool (5) Face (6) Port from double check valve (7) Plunger (8) Orifice (9) Port to rod end of tilt cylinder (11) Return oil (12) Cylinder pressureWhen the tilt controls for the quick coupler are in the hold position, tilt cylinder pressure acts against face (5) of spool (4). If the pressure exceeds a preset valve due to shock loading, valve spool (4) moves down and the excess pressure is relieved to the tank. This provides overpressure protection for the cylinder. This also provides overpressure protection for the lines.Tilt Back
Illustration 4 g00672302
Load control valve in tilt back position (1) Check valve (2) Chamber (3) Port to head end of cylinder (4) Spool (5) Face (6) Port from double check valve (7) Plunger (8) Orifice (9) Port to rod end of tilt cylinder (13) Quick coupler tilt back (pressure)When the quick coupler is tilted back, oil flows into the load control valve through port (6), check valve (1), chamber (2), and port (3) to the head end of the cylinder. Return oil from the rod end flows through an external line and the control valve to the tank.Tilt Forward
Illustration 5 g00672872
Load control valve in tilt forward position (1) Check valve (2) Chamber (3) Port to head end of cylinder (4) Spool (5) Face (6) Port from double check valve (7) Plunger (8) Orifice (9) Port to rod end of tilt cylinder (11) Return oil pressure (14) Quick coupler tilt forward (pressure)When the quick coupler is being tilted forward, oil flows from the bank valve to the rod end of the cylinder. A pilot line from the rod end of the cylinder is connected to port (9). This allows the rod end pressure to act through orifice (8) against the end of plunger (7). As pressure in the rod end of the cylinder increases, plunger (7) moves down and the plunger pushes spool (4). This unseats the spool and this allows return oil from the head end of the cylinder to flow through port (6) and the bank valve to the tank.