STICK AR-HOE 2058342 - Caterpillar

Illustration 1 g00589763
The illustration includes the control valves for the ripper (attachment). (1) Signal to pump through inlet manifold (2) Steering control valve (3) Bulldozer lift control valve (4) Bulldozer tilt control valve (5) Ripper lift control valve (6) Ripper tip control valve (7) Line from pilot valve (bulldozer lift) (8) ResolverThe resolver (8) is a ball check valve. Each control valve section in the implement hydraulic system has a resolver. Each resolver compares the pressure signal from the upstream control valve section and the pressure signal from the current control valve section. The higher signal of the two signals goes to the resolver in the downstream valve section. For example, the resolver in control valve (5) compares the signal from the resolver in control valve (6) to the signal from the resolver in control valve (5). The higher signal of the two signals goes to the resolver in control valve (4) .This means that the highest resolved signal from the implement control valve goes through line (1) to the compensator valve on the pump. The signal instructs the pump to vary pump output in order to meet the highest resolved load requirements. The pump compensator valve adds margin pressure to the load requirements. Note that the resolver network does not add various loads together. Instead, the single highest resolved load plus margin pressure governs the pump output. When the pilot control lever (bulldozer) is in the FLOAT position or in the DOWN position, the pilot control pressure enters the end of the resolver network. Therefore, the pump signal pressure is the sum of the pilot control pressure and the margin pressure. This maintains the necessary supply. Therefore, the entire system is supplied with 2100 kPa (305 psi) higher than the necessary pressure for handling the highest resolved pressure except at low pressure standby. When all the control levers are in the HOLD position and the pump is at low pressure standby, the pressure in the resolver network is zero.