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      5-10t Internal Combustion Counterbalance Forklift Truck                  Operation & Maintenance Manual 

 

-71- 

5.3.1 Vacuum Booster and Brake Master Cylinder 

Refer to Fig 5-5 for the outside drawing and Fig 5-6 for the internal structure of 9’’+10’’ 

double-diaphragm vacuum booster and brake master cylinder used for 5-7t forklift trucks, 

and the operating status of the assembly is briefly described as follows:   

(1)Non-Working Status 

When  vacuum  booster is under non-working status, the tapered large spring 3 will push 

the  control  valve  push  rod  1  together  with  the  control  valve  piston  5  to  the  limiting 

position  on  the  rear  end,  while  the  control  air  valve  4  is  pressed  tightly  on  part  5  by 

tapered  small  spring,  thus  to  close  the  air  valve  port.  At  this  point,  both  front  and  rear 

cavities of power-assisted air chamber are interlinked through the passage and the control 

valve  cavity  with  passage  B,  and  cut  off  from  atmosphere.  When  engine  and  vacuum 

pump  work,  certain  vacuum  degrees  are  available  in  both  front  and  rear  cavities  of 

power-assisted air chamber.   

 

Fig 5-5 Outside Drawing of Vacuum Booster and Brake Master Cylinder 

 

Summary of Contents for FD100T

Page 1: ...involved shall carefully observe the requirements and specifications for forklift trucks in this manual for the forklift trucks to regularly maintain a good technical condition Due to our continuous improvement of the forklift truck products the items of this manual are subject to alteration and may vary slightly from the real forklift trucks without prior notice for which your kind understanding ...

Page 2: ...1 5 3 Engine Oil Filter 25 1 5 4 Cooling System 25 1 5 5 Fastening of Bolts for Engine Cylinder Head 26 1 5 6 Adjustment of Valve Clearance 27 1 5 7 Confirmation of Ignition Time for Fuel Injection 28 1 5 8 Adjustment of Ignition Time for Fuel Injection 29 1 5 9 Determination of Compression Pressure 29 1 5 10 Exhaust of Injection Pump 29 2 Electrical System 30 2 1 Overview 30 2 2 Brief Introductio...

Page 3: ...al 81 6 Steering System 82 6 1 Steering Unit 84 6 1 1 Overview 84 6 1 2 Operating Principle 85 6 1 3 Application Requirements 86 6 1 4 Examination and Maintenance of Steering Unit 87 6 1 5 Failure and Removal for Steering Unit 89 6 2 Examination after Reassembly of Steering System 91 6 3 Failure Removal for Steering System 93 6 4 Steering Axle 93 6 4 1 Steering Axle Body 93 6 4 2 Left Right Steeri...

Page 4: ...d Tilt Cylinder 105 8 1 Lift Cylinder 105 8 2 Isolating Valve 108 8 3 Limiting Valve 108 8 4 Tilt Cylinder 110 9 Lifting System 111 9 1 Overview 112 9 2 Outer Inner Mast 112 9 3 Fork Carriage 112 9 4 Adjustment of Lifting System 112 9 4 1 Gasket Adjustment for Lift Cylinder Head 112 9 4 2 Height Adjustment for Fork Carriage 113 9 5 Mounting Positions of Rollers 114 ...

Page 5: ...klift truck at the lifting time III Storage of Forklift Truck 1 Drain the fuel completely It is not to be drained if coolant is the antirust and antifreeze fluid 2 Coat the surface of unpainted parts with antirust oil and coat the lift chain with lubricating oil 3 Drop the mast to the lowest position 4 Skid the parking brake 5 Wedge up the front and rear tyres properly using wedge blocks IV Prepar...

Page 6: ...ck is driven on a ramp larger than 1 10 Turning shall be avoided by all means and please never perform loading unloading operation when forklift truck is running downgrade 8 It is required to pay attention to passengers obstacles and low lying pavements and pay attention to the clearance above the forklift truck during driving 9 It is not allowed for anyone to stand on fork and it is not allowed f...

Page 7: ... wheels when the truck is to be parked there for a long time 19 It is not allowed to open radiator cover carelessly under the condition when engine is very hot 20 The pressures of multi way valve and safety valve have been properly adjusted before delivery of forklift truck from factory and users shall not adjust them at discretion during use to avoid damage of entire hydraulic system and hydrauli...

Page 8: ...ck 1 Fuel Gage 13 Lift Handle 2 Indicator Light 14 Tilt Handle 3 Water Temperature Gauge 15 Parking Brake Handle 4 Hour Meter 16 Front Rear Gear Handle 8 Ignition Switch 19 Inching Pedal 9 Light Switch 20 Brake Pedal 10 Horn Pushbutton 21 Throttle Accelerator Pedal 11 Steering Light Switch 22 Engine Hood Stay Cable 12 Steering Wheel 23 Engine Stop Stay Cable ...

Page 9: ... etc Examine whether or not the respective parts including instruments illumination connection joints switches and electrical circuit are working normally 2 Oils Greases and Anti freeze Fluids Used for Forklift Truck Name Original Oil Product Brand Code and Temperature of Use Gasoline 93 or 97 Brand of Light Diesel Oil 0 10 20 35 Diesel Oil Application Temperature 4 5 5 14 14 29 Viscosity Grade 5W...

Page 10: ...ing Yiping 4604 Synthetic Brake Fluid GB12981HZY4 Lubricating Grease Great Wall 3 General Lithium Base Lubricating Grease 20 120 Viscosity Grade 85W 90GL 5 80W 90GL 5 Heavy duty Truck Gear Oil HAIPAI Application Temperature 15 49 25 49 Code FD 1 FD 2 FD 2A FD 3 Anti freeze Fluid Jinbai Application Temperature 25 35 45 50 ...

Page 11: ... build up a specified pressure system 2 There is a feeding tank on the left side of engine with the marks of FULL and LOW labeled in the upper and lower parts of the tank wall and the level of anti freeze fluid shall be between these two countermarks during use Antirust and anti freeze fluid of the same model shall be supplied after anti freeze fluid is leaked out or evaporated Anti freezing fluid...

Page 12: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 12 ...

Page 13: ... Front Rear S T 1470 1700 1600 1700 Clearance Front Rear K M 590 600 590 675 590 740 700 740 718 740 Whole Length H 4660 4735 4800 5160 5480 Entire Length Q 1995 2165 2245 Mast C mm 2500 2625 2700 2850 Whole Height Overhead Guard P mm 2450 2585 Height at Rise of Fork with Cargo Stop Frame A 4420 4330 Length J 1220 Fork Width Thickness F 150 55 150 60 150 65 170 70 175 80 Fork Adjusting Range Outer...

Page 14: ... 63 2 58 51 57 Vehicle Type Parameter FD50 70T MWF FD50 70T MGH FD50 60T MWJ FD50 70T MWH Model Isuzu Diesel A 6BG1QC Chaochai 6102BG Mitsubishi Diesel S6S T Perkins 1104D 44TA Number of Cylinders Diameter of Cylinder Stroke mm 6 105 125 6 102 118 6 94 120 4 105 127 Rated Power Rotating Speed Kw rp m 82 3 2000 81 2500 67 6 2300 83 2300 Max Torque Rotating Speed Nm rp m 416 1400 1600 353 1650 293 1...

Page 15: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 15 ...

Page 16: ...d Installation Including muffler front vent pipe rubber gasket connecting pipe vent pipe and U bolt for block plate 6 Electrical System Mainly including light fittings instruments wire harnesses and electrical components 7 Drive Axle and Installation Mainly including axle housing transmission speed differential wheel sided reducer half shaft and brake 8 Front Wheel Assembly Including tyre front wh...

Page 17: ...ck frame transmission bracket bracket for tilt cylinder engine bracket and battery cover plate 20 Counterweight and Installation Including counterweight traction bolt and netting guard 21 Instrument Bracket and Hook Installation Including instrument bracket internal combustion engine hood floor articulation cross beam radiator cover plate and air spring 22 Seat and Installation Including seats and...

Page 18: ... Maintenance of Forklift Truck 1 Power System 1 1 Overview Power system mainly includes engine fuel system cooling system and exhaust system Engine is installed on truck frame through rubber pads to reduce vibration Engine torque converter transmission transmission shaft and drive axle are formed into a unit Refer to Fig 1 1 ...

Page 19: ...aoyang 6102BG 38 Engines for 8 10t forklift trucks include imported diesel engine Isuzu 6BG1 and homemade diesel engine Chaoyang 6102BG The imported Isuzu 6BG1 model diesel engine is mainly described here and the others will not be described here as user may refer to the attached operation manual for engines Refer to Fig 1 2 for the outside structural drawing for 6BG1 and refer to the attached Tab...

Page 20: ...cating Device Pump Type Drive Type Oil Pressure Adjusting Device Oil Pressure Indicating Device Filter Mode Cooler Cooling Device Cooling Mode Cooling Fan Drive Mode A 6BG1QC 4 stroke Water cooling Straight line and top Diesel Engine 6 105 125 6 494 17 2000 82 3 416 1400 1600 233 700 450 1129 5 672 0 860 0 1 5 3 6 2 4 Looking from the end of fan in clockwise direction Top Mounted Boshing Type 9 5 ...

Page 21: ...egulator Referential Parameters Oil Quantity in Oil Pan Cooling Water Quantity Valve Clearance Suction Valve Exhaust Valve Valve On Off Time Suction Valve Open Close Exhaust Valve Open Close Injection Period Injection Starting Pressure Compression Pressure Vortex Type Belt Drive Wax Pellet Type 82 95 Magnetic Engagement Type 24V 4 5KW Disconnecting Fuel Passage Available AC Generation and Diode Re...

Page 22: ...e mounted on the left side of the truck frame with fuel tank cover plate on top and fuel sensor mounted on the plate Refer to Fig 1 3 1 3 2 Fuel Sensor Device The function of fuel sensor device is to transform the oil quantity stored in fuel tank into current through up and down movement of float to be ultimately responded to the fuel gage on instrument panel to allow people to visually understand...

Page 23: ...uel to engine as well under the condition when core of filter is blocked 1 4 Cooling System Cooling system is composed of water pump fan radiator and assistant radiator Water pump is installed on engine and the crankshaft actuates the work of water pump through V shaped rubber belt 1 5 Examination and Adjustment In order for engine to maintain a good work status it is required to carry out regular...

Page 24: ...side for cleaning and the core of filter shall be replaced if it is severely block and cannot be cleaned or it has been damaged 3 Clean the dust inside the cover 1 5 2 Refer to Fig 1 6 for fuel filter 1 Demount the fuel filter using special wrench and it shall be replaced if damaged or blocked 2 Add several drips of fuel around the seal ring along the new fuel filter and then mount it on Further s...

Page 25: ...adiator is reduced and it is required to add coolant when the level of coolant is lower than the scale line of LOW and it shall be added up to the place of 2 3 scale between the upper and lower countermarks 2 Replace the coolant A Open the radiator cover after shutdown for more than half an hour and until it has been cooled down and loosen the water drain valve on the underside of radiator B Loose...

Page 26: ...outwards Press the belt in the place of A with finger using a 10kg force and its deflection is at about 10mm Then tighten the bolts B and C in order Fig 1 9 1 5 5 Fastening of Bolts for Engine Cylinder Head 1 Tighten the bolts for cylinder head one by one at a 68Nm torque following the sequence as indicated in Fig 1 10 2 Further increase the tightening torque to 93Nm and tighten respective bolts o...

Page 27: ... pointer are consistent it indicates upper dead center of compression stroke for the 1st cylinder Adjust the valve clearance of countermark and adjust the valve clearance of countermark as well Valve Clearance Value 0 4mm the same value for both suction and exhaust under the cold status Refer to Figs 1 11 1 12 and 1 13 for details Fig 1 12 Fig 1 13 Refer to Table 1 2 for specific adjustment Cylind...

Page 28: ...sition in clockwise direction by about 30 Refer to Fig 1 15 3 Loosen the injection pipe of the 1st cylinder then detach the spring and discharge valve on the bracket of discharge valve and then mount the bracket for discharge valve on the fuel injection pump Refer to Fig 1 16 Fig 1 16 4 Slow turn the crankshaft in the clockwise direction at the same time while fuel feed pump is compressing and del...

Page 29: ...st cylinder and assemble the respective pipes at their original separate positions 1 5 9 Determination of Compression Pressure Refer to Fig 1 18 1 Detach the heating spark plug and injection pipes totally 2 Fit on the pressure gauge in the assembling part for heating spark plug of the first cylinder calibrated value as 500N 2 3 Use fully charged battery to allow the rotation of starting device and...

Page 30: ... and its function is to start engine 3 Shutdown Control System Shutdown control system mainly consists of start switch flameout relay and flameout stay wire flameout solenoid valve etc 4 Instrument System It mainly includes hour meter and oil quantity gage as well as charging indicator light oil pressure indicator light neutral position indicator light air filter blockage warning light and oil wat...

Page 31: ...nterbalance Forklift Truck Operation Maintenance Manual 31 5 10t MWF 6102 Electrical Schematic Diagram Power Supply Ignition Start Instrument Indication Valve Block Control Acousto Optical Signal Illumination Cab Electric Appliance ...

Page 32: ...terbalance Forklift Truck Operation Maintenance Manual 32 5 10 t MGH 6BG1 Electrical Schematic Diagram Power Supply Ignition Start Instrument Indication Valve Block Control Acousto Optical Signal Illumination Cab Electric Appliance ...

Page 33: ...terbalance Forklift Truck Operation Maintenance Manual 33 5 7 t MWJ S6S T Electrical Schematic Diagram Power Supply Ignition Start Instrument Indication Valve Block Control Acousto Optical Signal Illumination Cab Electric Appliance ...

Page 34: ...rbalance Forklift Truck Operation Maintenance Manual 34 5 7 t MWH 1104D 44TA Electrical Schematic Diagram Power Supply Ignition Start Instrument Indication Valve Block Control Acousto Optical Signal Illumination Cab Electric Appliance ...

Page 35: ...ection to the 2nd gear Start Gear to start the engine After engine is started push the gear shift lever forward namely at the forward gear and accelerate the throttle the forklift truck will run at a quick speed or work at a quick speed and if the gear shift lever is pulled backwards namely at the backward gear the reversing light will turn on and the reversing buzzer sounds at this point 2 Light ...

Page 36: ...tatus and the oil pressure indicator light turns on it then indicates that the oil pressure of engine is too low and lubrication is not satisfactory while engine shall be shut down for examination 8 Oil Water Separator Signal Display Turn the start switch in clockwise direction to the 1st gear switched on gear before engine is started at this point the water sedimentation signal indicator light tu...

Page 37: ...emperature Gauge 2 Hour Meter 3 Fuel Gage 4 Left Turn Indicator Light 5 Oil Water Separator Indicator Light 6 Oil Pressure Indicator Light 7 Charging Indicator Light 8 Neutral Position Indicator Light 9 Preheating Indicator Light 10 Air Filter Blockage Indicator Light 11 Right Turn Indicator Light ...

Page 38: ...or eyes burn injury and blindness In the case when it touches skin water shall be used for flushing immediately while water shall be used for flushing and doctor shall be visited in time when it splashes into the eye 2 4 Wire Harness 1 Allowable Load Current Values for Nominal Sections of Low pressure Wire Section 2 0 5 0 8 1 0 1 5 2 5 3 0 4 0 5 0 6 0 Current Carrying Capacity A 11 14 20 22 25 25 ...

Page 39: ...Diameter and Torque Conversion Ratio 12 5 Φ315 Torque Conversion Ratio 3 1 Torque Converter Set Oil Feed Pressure MPa 0 5 0 7 Type Internal Gear Pump and Transmission Power Output Oil Feed Pump Flow Rate 1 min 40 2000rpm at 2MPa Type Power Gear Shift Number of Transmission Gears 2 Gears for Front and Rear Respectively Speed Ratio The Same for Both Front and Rear I 1 852 II 0 642 Friction Plate Out...

Page 40: ...ke 17 Oil Seal 2 Oil Feed Pump 10 Oil Filter 18 Ball Bearing 3 Ball Bearing 11 Oil Seal 19 Gear 4 Shaft 12 Gear 20 Backward Gear Clutch Subassembly 5 Ball Bearing 13 Ball Bearing 21 Forward Gear Clutch Subassembly 6 Torque Converter 14 Shaft 22 Elastic Pad Input Pad 7 Ball Bearing 15 Bearing Cover 23 Transmission Input Shaft 8 Gear 16 Output Shaft ...

Page 41: ...he pump impeller is actuated by elastic pad and the elastic pad is connected with flywheel At the same time while engine is rotating the pump impeller begins rotation as well Due to the effect of centrifugal force the liquid inside the pump impeller ejects along the blade lattice of pump impeller at this point it is transformed from mechanical energy into hydraulic energy Thus the liquid flows int...

Page 42: ...ue converter hence called two phases It is characterized by stable operation and improved efficiency One way clutch turbine pump impeller and guide pulley are installed inside the torque converter and the internal part of the torque converter is filled up with torque converter oil with warning point of oil temperature as 105 One gear in the end part of pump impeller is mutually engaged with the dr...

Page 43: ...ump is composed of driving gear and internal gear driven gear as well as housing and cover installed on the upper end of torque converter case The driving gear is actuated by pump impeller neutral position gear and driving gear of oil pump of torque converter and the oil feed pump supplies oil in the lower part of transmission to respective parts of the transmission Fig 3 3 Oil Feed Pump ...

Page 44: ...ther with pistons During operation the sealing property for external circle and internal circle of piston is respectively ensured by slide oil seal and O ring Under the status out of service the disc return spring is disengaged from hydraulic clutch and the surface of clutch is always lubricated by the oil returned from oil cooler to prevent surface adhesion and wear of clutch When the pressure oi...

Page 45: ...he valve body The overflow valve of hydraulic clutch is used to adjust the oil pressure of clutch inside the transmission while the overflow valve of torque converter is used to adjust the oil pressure flowing into the torque converter Inching valve stem is mutually coupled with the connecting rod of inching pedal and the valve stem is pressed in when inching pedal is pushed down Accordingly the c...

Page 46: ...o the oil sump through oil filter recycled in such a way When gear shift valve stem is at the middle position neutral gear the oil circuit from gear shift slide valve to clutch is closed and at this point all the liquid will flow into the torque converter When gear shift valve stem is at forward or backward position for the action of pressure regulating valve the oil enters into pressure accumulat...

Page 47: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 47 Fig 3 7 Torque Converter Oil Circuit System ...

Page 48: ... Place the gear shift lever at the middle position neutral gear This is because the oil feed pump cannot perform normal lubrication when it is out of service and it may possibly give rise to adhesion if rotation of drive wheel is transmitted to the gear of transmission and the clutch Hence the drive shaft shall be detached 3 8 Failure Removal 1 Insufficient Power Refer to Table 3 2 2 Abnormal Rise...

Page 49: ...g tension 6 Seal Ring or O Ring Damaged or Worn out Disassembling and examining To be replaced Torque Converter B Flywheel Damaged or Other Parts in Collision Extracting a small quantity of oil and examining whether or not extraneous substance exists To be replaced A Improper Use of Oil or Blistering Examining 1 Air Sucked at Oil Suction Side Examining joint and oil pipe Joint to be re tightened o...

Page 50: ... forklift truck running forward at middle position and the truck not working at backward C Positions of Inching Connecting Rod and Gear Shift Valve Rod Incorrect Examining and measuring To be adjusted Engine Engine Power Reduced Examining rotating speed at stall Examining the sound during work of engine and examining the maximum rotating speed at middle position at neutral position Engine to be ad...

Page 51: ...sts To be replaced 4 Air Sucked Examining the joint and oil pipe at the end of suction Joint to be tightened or gasket to be replaced 5 Water Blended into Oil Discharging oil and examining Oil to be replaced 6 Oil Flow Rate Low Examining whether or not pipeline is damaged or bent To be rehabilitated or replaced Torque Converter 7 Bearing Worn out or Blocked Disassembling and examining To be rehabi...

Page 52: ...oken Disassembling and examining To be replaced 4 Spline Worn out Disassembling and examining To be replaced 5 Loud noise with Oil Feed Pump Disassembling and examining To be rehabilitated or replaced Torque Converter 6 Bolt Loosened Disassembling and examining To be tightened or replaced 1 Bearing Worn out or Blocked Disassembling and examining To be replaced 2 Gear Broken Disassembling and exami...

Page 53: ...e Converter 5 Oil Pressure too Low Examining whether or not suction pressure is formed at oil inlet side of oil feed pump To be replaced 1 Oil Quantity Insufficient Examining oil level Oil to be added 2 Seal Ring Damaged Disassembling and examining To be replaced 3 Clutch Lamella Skidding Examining clutch oil pressure To be replaced 4 Shaft Broken Disassembling and examining To be replaced 5 Clutc...

Page 54: ...ket to be tightened or replaced 3 Joint and Oil Pipe Loosened Examining Pipe to be tightened or replaced 4 Oil Drain Plug Loosened Examining To be tightened or replaced 5 Oil Ejected out from Vent Hole Discharging oil and examining whether or not water is blended into oil examining whether or not air is sucked in the oil suction joint and examining the vent hole of air breather Oil to be replaced ...

Page 55: ... is coupled with the sector plate in front part of truck frame using bolts while mast is mounted on the drive axle housing 4 2 Main Transmission and Speed Differential Main transmission and speed differential are mainly comprised of left and right differential cases gear ring spiral bevel gear and driving pinion etc and they are all mounted inside the case of main transmission as indicated in Fig ...

Page 56: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 56 Fig 4 1 Drive Axle 5 7t ...

Page 57: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 57 Fig 4 2 Drive Axle 8 10t ...

Page 58: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 58 Fig 4 3 Ma in Re duc er and Dif fer enti al ...

Page 59: ...nside the planetary bracket The internal gear ring or through the seat of internal gear ring is assembled on the drive axle housing using spline The principle for power transmission is as follows Refer to Fig 4 4 When sun gear rotates namely the rotation of half shaft the rotation is transmitted to the planetary gears and the internal gear ring However as the internal gear ring is fixed on the two...

Page 60: ...o be tightened or replaced Vent Hole Blocked To be cleaned or replaced 1 Oil Leaked out from Main Reducer Casing Oil Seal Worn out or Damaged To be replaced Gear Worn out Damaged or Broken To be replaced Bearing Worn out Damaged or Broken To be replaced Gear Clearance Improper To be adjusted Fitting between coupling Half Shaft Gear and Spline of Half Shaft Loosened Parts to be replaced 2 Loud Nois...

Page 61: ...Spline 0 038 0 130 Tightening Torque of Bolt for Fixing Axle Housing and Main Reducer Casing 150 175 N m Fitting Diameter for Small Bearings at Both Ends of Axle Housing Fig 4 1 Mat 6 or Fig 4 2 S N 6 89 66 89 88 Fitting Diameter of Oil Seals at Both Ends of Axle Housing and Axle Housing 109 913 110 Tightening Torque of Bolt for Fixing Axle Housing and Frame 630 946 N m Tightening Torque of Bolt f...

Page 62: ...00 12 7 Wheel Brake Shoe Surface Area 2 4 324 4 489 Type Mounted on Intermediate Shaft of Transmission Mechanical and Internal Expanding Type Inner Diameter of Brake Drum Φ160 Shoe Dimension L W T 140 36 3 5 Parking Brake Shoe Surface Area 2 50 4 Brake Master Cylinder Φ31 75 Diameter of Vacuum Booster Front Case Rear Case Φ9 Φ10 Type Main Valve Safety Valve Open Core Type Close Core Type Movement ...

Page 63: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 63 ...

Page 64: ...t truck is utilized for power brake One circuit of pressure oil enters into the brake valve and enters into the brake wheel cylinder of the brake for brake to be generated while the other circuit of pressure oil enters into the energy accumulator for energy to be stored as standby Both circuits are controlled by the stroke of brake pedal 5 2 1 Brake Pedal Device Refer to Fig 5 2 The brake pedal an...

Page 65: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 65 ...

Page 66: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 66 Fig 5 2 Brake Pedal Device ...

Page 67: ... D chamber will push the recoil piston 5 rightwards and this thrust force and the pedal force are mutually balanced D When maximum pedal force is entered on the right end of piston bolt and pedal bracket are used for limitation in order not for the oil pressure in D chamber to exceed the maximum adjusting oil pressure E Release the foot from the pedal the counterforce of recoil piston as well as t...

Page 68: ...ns oil towards energy accumulator to push the piston to move leftward and compress the combination spring for oil pressure to be created At the same time the leftward movement of piston allows the switch control rod in the place of warning switch to move leftwards under the action of spring pressure for the switch valve core to fall in the place where the groove of switch control rod is located an...

Page 69: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 69 Fig 5 3 Brake Valve Fig 5 4 Energy Accumulator ...

Page 70: ...e a relatively high brake wheel cylinder oil pressure under the action of a relatively light brake pedal force to play a power assisting and labor saving function which has alleviated the driver s labor intensity and enhanced the safety of wheel brake Refer to Table 5 2 for main performance parameters Table 5 2 Name Calculation Unit Numerical Value Max Φ263 Effective Diameter of Vacuum Cylinder Mi...

Page 71: ...atus the tapered large spring 3 will push the control valve push rod 1 together with the control valve piston 5 to the limiting position on the rear end while the control air valve 4 is pressed tightly on part 5 by tapered small spring thus to close the air valve port At this point both front and rear cavities of power assisted air chamber are interlinked through the passage and the control valve ...

Page 72: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 72 Fig 5 6 Str uct ura l Dra win g for Vac uu m Bo ost er and Bra ke Ma ster Cyl ind er ...

Page 73: ...nt of the control valve push rod air continuously enters into the front and rear cavities of power assisted air chamber through the opened air valve port and the control valve body keeps moving forward When brake pedal stops being pushed and stays at certain position the control valve body also moves forward and stops at the position where the air valve port is closed At this point the vacuum valv...

Page 74: ...t Large while Pedal Force Turned to be Heavy 1 Vacuum of Booster Leaked 2 Engine Vacuum Pipeline Leaked Frequent Oil Starvation for Oil Reservoir 1 Joint Area of Cylinder Leaked 2 1st Piston Rubber Ring of Master Cylinder Worn out Brake Pedal Low and Soft 1 Air Present in Oil Circuit System 2 Clearance between Booster Push Rod and Master Cylinder Piston too Large 5 4 Wheel Brake The 5 7t wheel bra...

Page 75: ...spring The automatic clearance adjusting device takes effect during backward brake of forklift truck in general namely the adjusting lever automatically turn the gear on the adjuster by one tooth when clearance is big for the clearance to be maintained at 0 4 0 6mm after adjustment Refer to Fig 5 7 for the turning direction during gear adjustment As there are two forms of 5 7t wheel brake there ar...

Page 76: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 76 Fig 5 8 Brake 5 7t ...

Page 77: ...enance Manual 77 1 Clamping Brake Caliper Body 7 Piston 2 Deflating Valve 8 Inlet Oil Sealed Pump Cover 3 Friction Block Assembly Oil Seal Wheel Cylinder Head 4 O Ring 9 Hole Plug 5 Rectangular Seal Ring 10 Screw Plug 6 Dust Ring 11 Brake Disc Fig 5 9 Clamping Brake 8 10t ...

Page 78: ...t with certain frictional force One end of return spring is supported on the outer flange of sleeve while the other end is pressed on the cover plate and the cover plate is retained using retainer ring The sleeve is limited using friction snap ring During brake the piston moves under the hydraulic action the retainer ring on the piston actuates the cover plate to compress the return spring The pis...

Page 79: ...sion Refer to Fig 3 1 Sequence 9 Refer to Fig 5 12 for detailed structure Refer to Fig 5 11 for operation of parking brake Under the running status with standard load for forklift truck to perform parking brake on a ramp its hand operating force shall not be larger than 300N The size of pulling force is adjusted in the direction as indicated in the drawing and B is the point for measurement of for...

Page 80: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 80 Fig 5 11 Parking Brake ...

Page 81: ...ered with Impurity To be repaired or replaced Coupling Bolt Loosened and Bottom Plate Distorted To be repaired or replaced Friction Block Distorted or Assembly Incorrect after Assembly To be repaired or replaced Friction Plate Partially Worn out To be replaced Noise Present during Brake Work Wheel Bearing out of Condition To be replaced Surface of Friction Block Adhered with Impurity To be repaire...

Page 82: ...Unit Displacement ml min 280 Steering Unit Rated Pressure MPa 16 Type Cross Type and Double Action Type Cylinder Diameter Rod Diameter Φ115 Φ85 Steering Cylinder Stroke 2 216 2 260 Set Pressure MPa 12 3 Bypass Valve Rated Flow Rate 1 min 25 27 Type Central Supporting Shaft Supported and Cross Cylinder Type Steering Angle Outer Wheel Inner Wheel 79 50 Rear Wheel Tread 1700 Steering Axle Steering Kn...

Page 83: ...r to Fig 6 1 for steering control device Steering shaft and steering unit are connected through universal joint The steering wheel actuates the steering shaft and the universal joint for steering unit to act so as to achieve hydraulic steering The steering pipe column that supports the steering shaft is able to tilt forward and backward for a certain angle for it to be adjusted to a proper positio...

Page 84: ...l in a measuring way to achieve the rear wheel steering When engine is flamed out the oil pump is unable to supply oil and steering may be achieved manually Refer to Fig 6 2 for the schematic drawing of full hydraulic steering system and refer to Fig 6 3 for the drawing for the structure of steering unit Fig 6 2 Schematic Drawing for Fully Hydraulic Steering System 1 Steering Wheel and Steering Sh...

Page 85: ...the steering wheel to be in direct proportion It plays the function of manual oil pump during manual steering The universal driving shaft plays the function for transmitting torque When it is at the middle position namely when steering wheel is not turned the oil from oil pump returns to oil pipe through valve core in the open core system as in Fig 6 4 During power steering the oil from oil pump e...

Page 86: ... be higher than the mounting position of steering unit and oil suction pipe shall be inserted into the oil level thus to be able for oil supply during manual steering and at the same time to be able to avoid blending of air into oil To facilitate safety and repair it is recommended to set a pressure gauge adapter in the place of oil inlet for steering unit so that the pressure gauge can be install...

Page 87: ...erformed indoors 4 Notices for Assembly a Clean up all the parts using gasoline or coal oil prior to assembly and the paint if any on the bonding face shall be wiped up using acetone It is prohibited to scrub the parts using cotton yarn or rags while hair brush or silk cloth shall be used and the parts may be blown off using compressed air where there the condition permits The rubber ring shall ne...

Page 88: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 88 Fig 6 5 Drawing for Disassembly and Assembly of Steering Unit ...

Page 89: ...Bonding Face To be re cleaned Rubber Ring in Shaft Radial Place Damaged Leading to Oil Leak Rubber ring to be replaced Oil Leak Unsmooth Washer in the Place of Limit Bolt Leading to Oil Leak Washer to be grinded smooth or to be replaced Oil Supply for Oil Pump Insufficient Light for Slow Turn of Steering Wheel while Heavy for Quick Turn of Steering Wheel Proper oil pump to be selected or bypass va...

Page 90: ...according to Notices e for Assembly Steering out of Order Two way Overload Valve out of Order Steel Ball Blocked with Dirt or Spring out of Order The truck runs out or the cylinder stays motionless may possibly move slowly as well when steering wheel is turned Two way overload valve to be cleaned Failure of Steering Wheel For Automatic Return to Middle Position 1 Steering Column and Valve Core Ecc...

Page 91: ...n run the engine at the fixed idle speed to raise the oil temperature 4 Measure the steering force Park the forklift truck on a dry and flat pavement Use the parking brake attach the spring balancing device on the edge of steering wheel to measure the steering force and this force must be lower than 150N 5 In order to measure pressure use the pressure gauge 15 20MPa and shut off valve and the hose...

Page 92: ...ng cylinder and its work must be considered from two aspects namely nominal pressure and rated flow Pressure is used to actuate cylinder while flow rate is related to the acting speed of cylinder On this account even if pressure is normal reaching 12MPa but if flow rate is insufficient the steering cylinder is still unable for normal work leading to a heaving steering Accordingly when it is requir...

Page 93: ...ed To be disassembled for repair or for replacement Steering Force Changing Flow Control Valve Stem Worn out To be wholly replaced Safety Valve Normally Open Cannot be Closed To be wholly replaced Flow Control Valve Stem Blocked To be disassembled for repair or for replacement Steering Operation Difficult Flow Control Valve Stem worn out To be wholly replaced 6 4 Steering Axle Cross steering cylin...

Page 94: ...r holes of king pins and users shall add lubricating grease on time Lock pin is available between the king pins of steering knuckle assembly to fix it 6 4 3 Wheel Hub Wheel hub is a ball iron part and the wheel hubs are different as the tyres of 8 10t forklift trucks are not the same as those of 5 7t forklift trucks 6 4 4 Steering Cylinder The steering cylinder crossly mounted between the steering...

Page 95: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 95 Fig 6 8 Steering Axle Fig 6 9 Steering Cylinder ...

Page 96: ...BG CBHY G32 F3 5 ATΦ Duplicate Pump CBKa G432 ATΦR GBHY G32 F3 5 ATΦ Duplicate Pump Front Gear Pump Drawing No Equipped with Mitsubishi S6S T CBHY G25 F3 5 ATΦ Equipped with Japan 6BG1 Perkins 1104D CBKa G436 ATΦL CBKa G436 ATΦL Equipped with Chaochai 6102BG CBKa G432 ATΦL CBKa G432 ATΦL CBKa G432 ATΦL Main Oil Pump Rear Gear Pump Drawing No Equipped with Mitsubishi S6S T CBKa G432 ATΦL Type Doubl...

Page 97: ...r steering lift and tilt while the rear pump is only used for lift and tilt The oil pump is a gear pump mainly composed of driving gear driven gear and pump body namely the oil pump includes two gears and some other parts The driving gear and the driven gear are engaged Speaking from the forklift trucks with power brake the front pump is a duplex pump while the small pumps in serial connection are...

Page 98: ...cylinder are under the closed status Fig 7 2 Middle Position 2 Push in Slide Valve Refer to Fig 7 3 At this point the middle passage is under the closed status not through The oil from the oil inlet port bursts through load the one way valve and flows into the joint B of cylinder and the return oil from the joint A of cylinder returns to oil tank through low pressure passage By virtue of the retur...

Page 99: ...ing force at this point the pilot valve core E is opened the oil flows into the hole through around the valve core and then flows into the LP passage Refer to Fig 7 6 3 When the pilot valve core E is opened the pressure after the valve core C drops and therefore the valve core C will move rightwards and be seated on the pilot valve core E As a consequence the oil circuit b after the safety valve c...

Page 100: ... while the oil from the joint B returns to the oil tank and accordingly the mast will tip backward When tilt operating lever is pushed slide valve pushed in the oil from the oil pump flows into the joint B and the auto locking valve in the tilt slide valve is enabled by virtue of HP oil for the joint A to be connected to LP while the mast will tip forward accordingly However in the case when engin...

Page 101: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 101 Fig 7 10 Multi way Valve Control Device Fig 7 11 Oil Tank ...

Page 102: ...on Maintenance Manual 102 7 9 Oil Circuit of Hydraulic System Main Oil Circuit Refer to Fig 7 12 for principle of hydraulic system Refer to Fig 7 13 for oil circuit diagram of hydraulic system for 5 10t forklift truck Fig 7 12 Schematic Drawing of Hydraulic System ...

Page 103: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 103 Fig 7 13 Drawing of Oil Circuit for Hydraulic System 5 10t ...

Page 104: ...l on the other side will be pushed out by piston and return to oil tank through multi way valve 7 10 Maintenance 7 10 1 Disassembly of Multi way Valve Disassemble the multi way valve from the forklift truck and clean its external part 1 Remove the connecting blots for respective plates of multi way valve to be taken apart but don t lose the springs on the one way valve and the bonding face 2 Demou...

Page 105: ...Truck Tonnage Item 5 7t 8t 10t Type Single Action Piston Type Inner Diameter of Cylinder Φ80 Φ90 Φ100 Outer Diameter of Piston Rod Φ60 Φ70 Lift Cylinder Cylinder Stroke 1495 Type Double Action Piston Type Inner Diameter of Cylinder Φ115 Outer Diameter of Piston Rod Φ50 Tilt Cylinder Cylinder Stroke 6 12 227 242 8 1 Lift Cylinder Two single action lift cylinders are respectively fixed in the rear a...

Page 106: ...hen lift control lever is pulled backwards the HP oil is introduced into the cylinder through the oil inlet port of the lift cylinder and drives the piston rod and the walking beam for the Fork to rise through chain When the inner mast just begins to rise the height from the ground to the position of Fork is called the free lifting height and the height of mast does not change within this range Wh...

Page 107: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 107 Fig 8 2 Lift Cylinder 10t Forklift Truck ...

Page 108: ...he oil circuit between the multi way valve and the HP oil port of the two lift cylinders positioned close to the left lift cylinder Refer to Fig 8 4 Limiting valve is used to limit the dropping speed of fork when it is heavily loaded and refer to Fig 8 5 for its structure With regard to 8t and 10 t forklift trucks their structures are basically similar to those of the 5 7t forklift trucks as indic...

Page 109: ... gets into contact with the joint namely the opening G is closed Accordingly the return oil must pass the throttle plate to flow back to oil tank through E D H C B and A if the amount of return oil drained from inside the lift cylinder is abruptly increased the pressure in cavity F goes up and drives the valve core Fig 8 5 Sequence 5 to overcome the spring force and move rightwards for the opening...

Page 110: ...es inside the cylinder block under the effect of hydraulic oil pressure A steel backed bearing is pressed and fitted in the inner hole of the guide sleeve cylinder head and a Yx seal ring and a dust ring are additionally mounted used to prevent oil leak between piston rod and guide sleeve and the dust One o ring is installed on the surface of the external circumference of the guide sleeve that is ...

Page 111: ... Section Shape of Inner Mast Section Shape of Outer Mast Max Lifting Height Standard Mast 3000 Front Back Tip Angle Standard Status 6 12 Outer Diameter of Main Roller Φ151 5 Φ183 5 Outer Diameter of Side Roller Φ82 Roller Outer Diameter of Side Roller on Fork Carriage Φ102 Φ109 7 Φ119 Lift Chain Leaf Chain LH2044 4 4 Pitch 31 75 LH2444 4 4 Pitch 38 1 LH2844 4 4 Pitch 44 5 Fork Lifting Mode Hydraul...

Page 112: ...e sway of fork beam support plate or upper cross beam two limit rollers are installed and the limit rollers roll on the outer side face along the inner mast The main roller bears the longitudinal load and the main roller mounted above is exposed some part when the Fork rises to the maximum lifting height while the limit rollers above and the side rollers below withstand the traverse load Enough ri...

Page 113: ... chain for the exposure A of main roller in the lower part of fork carriage to be 1 4 1 3 that of the radius of the main roller Fig 9 2 3 Raise the fork to the maximum point and confirm that the clearance B between the limit block of fork carriage and the limit block of inner mast is 5 10mm Fig 9 3 4 Drop the Fork Carriage onto the ground and tilt backwards in place Adjust the adjusting nut for th...

Page 114: ...for 5 10t rollers is largely identical but with minor differences respectively represented in Fig 9 5 Fig 9 6 and Fig 9 7 The main roller bears the main load in the front and rear parts of forklift truck nonadjustable generally while the side roller bears the lateral load generally able for adjustment of left side and right side clearances using unit of adjusting shims for the inner mast and the f...

Page 115: ...5 10t Internal Combustion Counterbalance Forklift Truck Operation Maintenance Manual 115 Fig 9 7 Roller Installation 10t Forklift Truck ...

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