The multi-channel valve of hydraulic excavator is studied. The multi-channel valve is divided into two valve blocks a and B, which are connected by screws. A valve block includes: left travel valve, boom confluence valve, P2 pump unloading valve, swing valve, stick 1 valve and optional valve; Valve block B includes: travel straight in valve, P1 pump unloading valve, right travel valve, boom valve, bucket valve and stick 2 valve. The schematic diagram of the multi-channel valve hydraulic system is shown in Figure 2.4. The system is a double pump and double circuit system.
In Figure 2.3: on valve block a, PAL / PBL is the forward / backward pilot oil port of left travel valve; Al / BL is the forward / backward oil port of left travel valve: PB1 is the pilot oil port of boom confluence valve; PCA is the pilot oil port of P2 pump unloading valve; PAS / PBS is the right / left pilot oil port of swing valve; as / BS is the right / left oil port of swing valve; Paal / PBAL is the retraction / discharge pilot oil port of stick 1 valve; AAL / BAL is the retraction / discharge port of stick 1 valve; Pao / PBO is the pilot oil port of optional valve; AO / Bo is the optional valve port.
On valve block B, PTB is the pilot oil port of the travel straight inlet valve; PCB is the pilot oil port of the P1 pump unloading valve; par / PBR is the forward / backward pilot oil port of the right travel valve; AR / BR is the forward / backward oil port of the right travel valve; PAB / PBB is the boom valve lowering / lifting pilot oil port; AB / BB is the boom valve lowering / lifting oil port; PAC / PBC is the digging / unloading pilot oil port of bucket valve; AC / BC is the digging / unloading port of bucket valve; Paa2 / pba2 is the retraction / discharge pilot oil port of stick 2 valve; Aa2 / Ba2 is the retract / drain port of stick 2 valve.
