BAIC HL940A Loader Service Manual & Repair Guide PDF Download (EN)

SECTION 6 WORK EQUIPMENT SECTION 6 WORK EQUIPMENT Group 1 Structure and Function - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-1 Group 2 Operational Checks and Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-38 Group 3 Tests and Adjustments - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-54 Group 4 Disassembly and Assembly - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6-67

Стр. 1

SECTION 6 WORK EQUIPMENT SECTION 6 WORK EQUIPMENT GROUP 1 STRUCTURE AND FUNCTION GROUP 1 STRUCTURE AND FUNCTION 1. HYDRAULIC SYSTEM OUTLINE 1. HYDRAULIC SYSTEM OUTLINE The loader hydraulic system is a pilot operated, closed center system which is supplied with flow from the variable displacement piston main hydraulic pump. The loader system components are : · Main pump · Main control valve · Bucket cylinder · Boom cylinders · Remote control valve (Pilot control valve) · Safety valve The main control valve is load pressure independent flow distribution system which routes flow to the boom, bucket or auxiliary cylinders (not shown) when the respective spools are shifted.

Flow from the main pump is routed to the main control valve where pump outlet pressure is reduced to pilot circuit pressure. The main control valve flow to the remote control valve. The remote control valve routed flow to either end of each spool valve section in the main control valve to control spool stroke. A accumulator mounted on safety valve supplies a secondary pressure source to operated remote control valve so the boom can be lowered if the engine is off. The return circuit for the main hydraulic system have return filter inside the hydraulic tank. The return filter uses a filter element and a bypass valve. The bypass valve is located in the upside of filter. 6-1

Стр. 2

1 Main pump 2 Fan & brake pump 3 Main control valve 4 Control unit 5 Boom lowering valve 6 Control block 7 Remote control lever(EH, FNR) 8 Remote control lever(HYD) 9 Pressure sensor 10 Fan motor 11 Directional valve 12 Hyd oil cooler 13 Safety valve 14 Boom cylinder 15 Bucket cylinder 16 Steering cylinder 17 Steering unit 18 Line check valve 19 Accumulator LS1 P1 T1 M LS2 S1 41 2 4 3 1 B A B2 A2 B1 A1 B3 A3 42 A B 30 a3 A1 A2 T/M 11 b3 29 PARKING P T 40 P1 T1 P2 T2 28 PS PS 28 A B G1 P B3 G2 PS 27 26 26 S3 T2 12 S2 B2 B1 S1 15 dump rollback T1 PP 2 L S1 b2 a2 25 6-2 down up LH RH 1 3 4 2 P T 1.1 2.1 PS 28 B 9 PS 14 31 B.D/F B.U CRAWD DUMP 33 34 PS 9 a1 5 b1 35 D Pr EH RCV HYD RCV HYD RCV 32 8 A1 T 3 P3 LS3 DLS T3 P1 EH RCV TPr 13 X1 1 L L1 S1 24 23 10bar PS B1 37 9 2.

HYDRAULIC CIRCUIT (HL940A, HL940A XT) 2. HYDRAULIC CIRCUIT (HL940A, HL940A XT) 7 20 16 E/G T P ( ) : 2spool RH LH 17 Control Unit / Electro Hydraulic, Joystick steering 6(4) 3(2) 5(3) 2(1) x To MCV Boom up B/Down Bucket In Dump Aux Up Aux Down R L AUX1 BUCKET BOOM EH20 EH19 EH22 EH21 a3 b3 a2 b2 a1 b1 19 LS T P STD : (17) LS ----------------------- DLS (3) J-Steering : (17) LS -- LS2 (22) LS1 -- DLS (3) 18 39 S P P1 M T 7 16 CR CL LS2 L R A LS1 38 PS M EH17 EH18 4 1 T T 36 4 Cut Off EH Valve SOL P 6 22 TE Electronics PE P 21 PVE 40 b3 P3 LS3 DLS T3

Стр. 3

1 Main pump 2 Fan & brake pump 3 Main control valve 4 Control unit 5 Boom lowering valve 6 Control block 7 Remote control lever(EH, FNR) 8 Remote control lever(HYD) 9 Pressure sensor 10 Fan motor 11 Directional valve 12 Hyd oil cooler 13 Safety valve 14 Boom cylinder 15 Bucket cylinder 16 Steering cylinder 17 Steering unit 18 Line check valve 19 Accumulator 20 Orifice 21 Joystick steering lever (opt) 22 Joystick steering valve (opt) Steering sensor(opt) 24 Adapter(opt) 25 Cut off valve 26,27 Accumulator 28 Pressure sensor 29 Brake valve 30 Pressure switch 31 Hydraulic tank 32 Air breather 33 Return filter 34 Bypass valve 35 Strainer assy Motor pump (opt) 37 Check block (opt) 38 Pressure sensor (opt) 39 Check valve (opt) 40 Accumulator (opt) 41 Quick coupler cylinder (opt) 42 Solenoid valve (opt) LS1 P1 T1 M LS2 S1 D 41 2 4 3 1 B A B2 A2 B1 A1 B3 A3 42 A B 30 a3 A1 A2 T/M 11 b3 29 PARKING P T 40 P1 T1 P2 T2 28 PS PS 28 A B G1 P B3 G2 PS 27 26 26 S3 T2 12 15 S2 B2 B1 S1 rollback down dump T1 PP 2 L S1 b2 a2 25 6-2-1 up LH RH 1 3 4 2 P T 1.1 2.1 PS 28 B 9 PS 14 31 B.D/F B.U CRAWD DUMP 33 34 PS 9 a1 5 b1 35 D Pr 8 EH RCV HYD RCV A1 HYD RCV 32 T 3 P3 LS3 DLS T3 P1 EH RCV 24 23 TPr 13 X1 1 L L1 S1 10bar PS B1 37 9 7 20 16 17 E/G T P ( ) :

2spool RH LH Control Unit / Electro Hydraulic, Joystick steering 6(4) 3(2) 5(3) 2(1) x To MCV Boom up B/Down Bucket In Dump Aux Up Aux Down R L LS T P HYDRAULIC CIRCUIT (HL940A TM) HYDRAULIC CIRCUIT (HL940A TM) AUX1 BUCKET BOOM EH20 EH19 EH22 EH21 a3 b3 a2 b2 a1 b1 19 STD : (17) LS ----------------------- DLS (3) J-Steering : (17) LS -- LS2 (22) LS1 -- DLS (3) 18 39 S P P1 M T 7 16 CR CL LS2 L R A LS1 38 PS M EH17 EH18 4 1 T T 36 4 Cut Off EH Valve SOL P 6 22 TE 21 PVE Electronics PE P P3 LS3 DLS T3

Стр. 4