Dynamic Acera 01/04-MC Page 5-1
KobelcoDynamicAcera
Kobelco Construction Machinery America LLCHydraulic Components
Kobelco ConstructionMachinery America LLC
Dynamic Acera 01/04-MCPage 5-2
4. COMPONENTS AND CIRCUIT DIAGRAM4-1 Layout of Hydraulic components (SK210)
A/CCompressor
Radiator &Oil cooler
HYDRAULIC COMPONENTS
(Battery relay) Fuel tank Hydraulic tank Controlvalve
Pump
Engine
(Receiver tank)Sub tank
(A/C Condenser)
(Solenoid proportional valve block)
(Sensor block)
Air cleaner
Washer tank
(A/C Unit)Pilot valve (LH)(Arm, Swing)
Pilot valve (RH)(Boom, Bucket)
Travel pilot valve
Swivel joint
Slewing motor
(Battery)
Dynamic Acera 01/04-MC Page 5-3
Typical of SK210 SK250
HYDRAULIC TANK
Sight Gauge
Suction inlet port
Tank return tomain Filters
Main FilterCompartmentAir Breather
Pilot Filter Manifold
Filter(Remove,
Replace every500 Hours)
Cover(Remove,
Replace filter& Reinstall)
Base(with one
way checks)
Cap
Filter(Remove,Clean &
Reinstall)
O-ring(Replace &Lubricate)
Dynamic Acera 01/04-MCPage 5-4
Typical of SK210 SK250
MINOR CHANGE HYDRAULIC TANK
Sight Gauge
Suction inlet port
Tank return tomain Filters
Main FilterCompartmentAir Breather
Pilot Filter Manifold
Filter(Remove,
Replace every500 Hours)
Cover(Remove,
Replace filter& Reinstall)
Base(with one
way checks)
Cap
Filter(Remove,Clean &
Reinstall)
O-ring(Replace &Lubricate)
Dynamic Acera 01/04-MC Page 5-5
Typical of SK210 SK250
NOTEAlways consult you operation manual for propermaintenance intervals.
Service Interval : 2000 hrs - Normal Conditions
O-Ring
Sucton Strainer
Service Interval : 500 hrs - Normal ConditionsOption/Breaker Filter : 250 hrs.
Dynamic Acera 01/04-MCPage 5-6
HYDRAULIC TANK
Main Return Filter
Service Interval : 500 hrs - Normal ConditionsOption/Breaker Filter : 250 hrs.Note: Always consult you operation manual forproper maintenance intervals.Main Return Filter Bypass Check Valve
If the main return filter plugs due to excessivecontamination then unfiltered oil will bypass thefilter thru this check valve and continue to supplythe main pump with lubrication oil
Dynamic Acera 01/04-MC Page 5-7
Typical Location of SK290 SK330
Bypass CheckValve
HYDRAULIC TANK
BypassCheck Valve
Typical Location of SK210 SK250
Dynamic Acera 01/04-MCPage 5-8
HYDRAULIC PUMP
Typical of SK160
Proportional Valve Non AdjustablePositive Control
Dynamic Acera 01/04-MC Page 5-9
HYDRAULIC PUMP
Typical of ED190
Dozer Gear pump
Dynamic Acera 01/04-MCPage 5-10
OLD Style Pump SK210 ~330
Port a2 Port a1
High PressureSensors
Port a3
Back-upMode Spool
Pump Casing Fill& air bleeder Plug
Auxarily Pump mount
HYDRAULIC PUMP
Back-upMode Spool
Dynamic Acera 01/04-MC Page 5-11
Minor Change Style Pump SK210 ~290
Port a2 Port a1
High PressureSensors
Port a3
IndependantTravel BypassBlock
Pump Casing Fill& air bleeder Plug
Auxarily Pump mount
MINOR CHANGE HYDRAULIC PUMP
Back-upMode Spool
Dynamic Acera 01/04-MCPage 5-12
Pilot Pump - Specified as P33) Gear pump (For pilot control)
Hydraulic circuit
Note:1. After assembly of gear pump, check that the drive gear rotates smoothly at 0.1 Nm {1.0
kgfm} or less.2. After assembly of gear pump, apply sufficient oil in the gear section.3. Bring the opposite side of caulking of the filter shown in the left figure into contact with the
insert end face, paying attention to the installing direction.
C ode N am e Q ty.307 P oppe t 1 308 S eat 1 309 S pring seat 1 310 S pring 1 311 A d just screw 1 312 Lock nu t 1 351 G ear case 1 353 D rive gear 1 354 D riven gear 1 355 F ilte r 1 361 F ront case 1 433 S ocket bo lt (M 8 x 40) 2 434 S ocket bo lt (M 8 x 55) 2 435 S ocket bo lt (M 8 x 20) 4 466 P lug (P F 1 /4 ) 1 467 A dapter (PF 1 /2P F 3/8) 1 700 S quare ring 1 710 O -ring (J IS B 2401-G 95) 1 725 O -ring (J IS B 2401-P 11) 1 728 O -ring (J IS B 2401-P 18) 1 732 O -ring (J IS B 2401-P 16) 1 850 Locking ring (J IS B 2804-R R -18) 1
Code Thread size 312 M 14 x 1.5 29.4 {3.0} 433, 434 435 466 PF 1/4 15.7 {1.6}
T ightening torque
M 8
Torque Nm {kgfm }
16.7 {1.7}
HYDRAULIC PUMP
Dynamic Acera 01/04-MC Page 5-13
HYDRAULIC PUMP
Negative Control Typical of SK210 ~330 ( Old Style Pump)
Negative Control Typical of SK210 ~330 ( Old Style Pump)
Dynamic Acera 01/04-MCPage 5-14
Positive Control Typical of SK210
Positive Control Typical of SK210
MINOR CHANGE HYDRAULIC PUMP
Dynamic Acera 01/04-MC Page 5-15
HYDRAULIC PUMP
Note: GPM given are ApproximateGPM = RPM X C.C. X .000261 Ounce U.S. = 29.5 C.C.
PUMP FLOW:SK160/ED190:MAX GPM: 37.9 X 2 PUMPSSK 210:MAX GPM: 55.5 X 2 PUMPSSK250:MAX GPM: 63.4 X 2 PUMPSSK290:MAX GPM: 63.4 X 2 PUMPSSK330:MAX GPM: 66.8 X 2 PumpsSK480:MAX GPM: 97.7 X 2 Pumps
Typical of SK210 ~330
Dynamic Acera 01/04-MCPage 5-16
3. Structure1) Main pump
HYDRAULIC PUMP
Typical of SK210 ~330
Code Name Qty. Code Name Qty. Code Name Qty.111 Shaft (Front) 1 313 Valve plate (R) 1 725 O-ring (JIS B2401-P11) 7 113 Shaft (Rear) 1 314 Valve plate (L) 1 728 O-ring (JIS B2401-P24) 4 114 Spline joint 1 325 Cover 1 732 O-ring 2 123 Roller bearing 2 401 Socket bolt (M20 x 210) 8 774 Oil seal 1 124 Needle bearing 2 406 Socket bolt (M8 x 20) 4 127 Bearing spacer 4 407 Socket bolt (M6 x 30) 3 141 Cylinder block 2 466 VP plug (PF 1/4) 2 151 Piston 18 468 VP plug (PF 3/4) 4 152 Shoe 18 490 Plug (Meck) 20 806 Nut (M16) 2 153 Retainer 2 531 Tilting pin 2 808 Nut (M20) 2 156 Spherical bushing 2 532 Servo piston 2 824 Snap ring 2
157 Cylinder spring 18 534 Stopper (L) 2 885 Pin ( 8 x 12L) 2 211 Shoe plate 2 535 Stopper (S) 2 886 Spring pin 4 212 Swash plate 2 546 Spacer 2 901 Eye bolt (M10) 2 214 Tilting bushing 2 548 Feed back pin 2 953 Set screw 2 251 Support 2 702 O-ring 2 954 Set screw 2 261 Seal cover 1 710 O-ring (JIS B2401-G95) 1 981 Name plate 1 271 Pump casing 2 717 O-ring (JIS B2401-G145) 4 983 Rivet 2 312 Valve block 1 724 O-ring (JIS B2401-P8) 16
2
792 Back-up ring (JIS B2407-G35)
2
789 Back-up ring (JIS B2407-P18)
Dynamic Acera 01/04-MC Page 5-17
Internal Pump Control:Internal pressure is applied on the small side of the Servo piston to maintain positon whenthe pump flow rate is increased this is accomplished by two things.1. PSV pressure enters the requlator on the large side of the servo piston to position thepump swash plate angle to minumn.2. The PSV pressure is reduced on the large side of the servo piston which allowspressure on the large piston side of the servo piston to be redirected to tank allowing thepump to come on stroke and increase the pump flow.
This internal differential pressureization allow variable control and also a more smoothcontrol on the pump flow output.
HYDRAULIC PUMP REGULATOR
Minumn Stroke Angle Maxumn Stroke Angle
Minimum Angle Maximum Angle
Dynamic Acera 01/04-MCPage 5-18
HYDRAULIC PUMP REGULATOR
Dynamic Acera 01/04-MC Page 5-19
2) Regulator Structure of regulator
HYDRAULIC PUMP REGULATOR (NEGATIVE CONTROL)
P
P
a1 PSV
PN
a3
a2
PH
B1
Dynamic Acera 01/04-MCPage 5-20
Pi1 Pi2
T2
P1' P2'
a1 a2
SE23SE22
A3D3
PH1
a2A1 A2a1PH2
M
PSVP2
PN2
a4
PN1
a5
B3
B1
a3
Dr
PSVP1 PP
~85
psi
~85
psi
MINOR CHANGE REGULATOR (POSITIVE CONTROL)
Dynamic Acera 01/04-MC Page 5-21
Code Name Qty. Code Name Qty.412 Socket bolt (M8 x 50) 2 730 O-ring (JIS B2401-P22) 1 413 Socket bolt (M8 x 70) 2 732 O-ring (JIS B2401-P16) 2 418 Socket bolt (M5 x 12) 2 733 O-ring (JIS B2401-P20) 2 436 Socket bolt (M6 x 50) 5 734 O-ring (JIS B2401-G25) 1 438 Socket bolt (M6 x 20) 4 753 O-ring (JIS B2401-P9) 1 439 Socket bolt (M6 x 40) 4 755 O-ring (JIS B2401-P11) 6 466 VP plug (PF 1/4) 3 756 O-ring (JIS B2401-P26) 2 467 Plug (PF 3/8 x M8) 1 763 O-ring (JIS B2401-G35) 1 496 Plug 18 801 Lock nut (M8) 3 541 Seat 2 814 Snap ring (JIS B2804 SR-15) 1 543 Stopper 1 2 836 Snap ring 1 545 Ball 2 858 Locking ring (JIS B2804 RR-15) 2
601 Casing 1 874 Pin ( 4 x 11.7L) 1 611 Feed back lever 1 875 Pin ( 4 x 8L) 4 612 Lever (1) 1 887 Pin 1
613 Lever (2) 1 897 Pin ( 4 x 19L) 1 614 Fulcram plug 1 898 Pin ( 6.5 x 9L) 1 615 Adjust plug 1 924 Set screw 1 621 Compensating piston 1 925 Set screw (Q1) 1 622 Piston casing 1 623 Compensating rod 1 079 Solenoid valve 1 624 Spring seat (C) 1 625 Outer spring 1 626 Inner spring 1 627 Plunger (C) 1 628 Adjust screw (C) 1 629 Cover (C) 1 630 Lock nut 1 631 Pf sleeve 1 641 Pilot cover 1 642 rod 1 643 Pilot piston 1 644 Spring seat (Q) 1 645 Plunger (Q) 1 646 Pilot spring 1 651 sleeve 1 652 spool 1 653 spring seat 1 Code Size654 Return spring 1 412, 413 M8 29.4 {3}655 Set spring 1 436, 438, 439 M6 11.8 {1.2}656 Port plate 1 466 PF 1/4 36.3 {3.7}708 O-ring (JIS B2401-G75) 1 467 PF 3/8 73.5 {7.5}722 O-ring (JIS B2401-P6) 2 496 PTF 1/ 8.8 {0.9}724 O-ring (JIS B2401-P8) 12 630 30 X 1 156.8 {16}725 O-ring (JIS B2401-P10) 1 801 M8 15.7 {1.6}727 O-ring (JIS B2401-P14) 1 728 O-ring (JIS B2401-P18) 1
Tightening torqueTorque
HYDRAULIC PUMP REGULATOR
Dynamic Acera 01/04-MCPage 5-22
HYDRAULIC MAIN CONTROL VALVE
Typical of SK210 SK250
Travel Straight
Boom
Swing
Bucket
Travel Left
Travel Right
Boom Conflux
P1 by-pass cut (Top) &Arm Conflux (bottom)
ArmV/R (top)&P2 by-pass cut (bottom)
Negative Control Relief
Swing Priority
Arm
Back Pressure PortFront of Machine
CircuitRelief
Dynamic Acera 01/04-MC Page 5-23
HYDRAULIC MAIN CONTROL VALVE
Boom Holding Valve
Option ValveActivation Port
Travel Straight
Travel Right
Bucket
Travel LeftSwing
AVRArm Variable Regen(top)
Boom
P1 By-Pass Cut(Top)
Arm
BoomConflux
Typical of SK210 SK250
Main Relief
Front of Machine
Dynamic Acera 01/04-MCPage 5-24
MINOR CHANGE MAIN CONTROL VALVE (Positive Control)
Typical of MINOR CHANGE SK210 SK250
Travel Straight
Boom
Swing
BucketTravel Left
Travel Right
Boom Conflux
P1 by-pass cut (Top) &Arm Conflux (bottom)
ArmV/R (top)&P2 by-pass cut (bottom)Auxiliary Port
(STD. Blank)
Low Flow Port
Arm
Front of Machine
CircuitRelief
Auxiliary ValveActivation Port
Dynamic Acera 01/04-MC Page 5-25
MINOR CHANGE MAIN CONTROL VALVE (Positive Control)
Boom Holding Valve
Option ValveActivation Port
Travel Straight
Travel Right
Bucket
Travel Left
Swing
AVRArm Variable Regen(top)
Boom
P1 By-Pass Cut(Top)
Arm
BoomConflux
Typical of MINOR CHANGE SK210 SK250
Main Relief
Front of Machine
Dynamic Acera 01/04-MCPage 5-26
HYDRAULIC MAIN CONTROL VALVE
Front of Machine
Typical of SK480
Travel Straight
Travel Right
Bucket
Travel Left
Swing
Arm
Main Relief
ArmConflux
Boom BoomConflux
Option 1
Cover foroption -2 block
Dynamic Acera 01/04-MC Page 5-27
1. The material of casing has changed from casting iron to aluminum alloy to makelighter weight .
2. Shuttle block on lower part is canceled, and low pressure sensor is used to sendpilot secondary pressure signal to controller.
Note: 1. P port inlet has a filter of 40 mesh or more to protect spool from foreign matter.
2. Before tightening adjusting nut ofpilot valve, apply Locktite #277 onjoint thread section.
3. Apply grease on rotating and slidingsections of joint, and give attentionto the assembling direction.
4. Apply grease on push rod top end.5. Thickness of washer 2 (shim) for
regulating secondary pressure ist = 0.4.
6. Not allowed to use seal washer again.
Type PV48K1008 Max. primary pressure 50 kgf/cm, ( 711 PSI ) Max. back pressure 3 kgf/cm, ( 42 PSI ) Rated flow rate 20 L/min Weight 1.9 kg
HYDRAULIC COMPONENTS7-7 Pilot valve (for Attachment)
Dynamic Acera 01/04-MCPage 5-28
3. ConstructionCross sectional view
HYDRAULIC COMPONENTS
Code Name Qty.Torque
Nm {kgfm}Code Name Qty.
TorqueNm {kgfm}
101 Casing 1 216-1 Spring seat 1 2 111 Port plate 1 216-2 Spring seat 2 2 121 Seal washer 2 217 Washer 2 (shim) 4 122 O-ring 1 218-1 Spring seat 1 2 125 Socket bolt (M8 x 35) 2 20.6 {2.1} 218-2 Spring seat 2 2 126 Spring pin 1 221-1 Spring 2 131 Bushing 1 221-2 Spring 2 151 Plate 1 241-1 Spring 2 201-1 Spool 2 241-2 Spring 2 201-2 Spool 2 246 Spring 4 211 Plug 4 301 Joing (M14) 1 47 {4.8} 212 Push rod 4 302 Plate 1 213 Seal 4 312 Adjusting nut (M14) 1 69 {7} 214 O-ring (1B P20) 4 501 Boot 1
Dynamic Acera 01/04-MC Page 5-29
7-8 Pilot valve (for traveling)1. Appearance
2. Specifications
3. Hydraulic diagram
4. Control curve
Code Port name Size TorqueNm {kgfm}1 Left travel forward port2 Left travel reverse port3 Right travel forward port4 Right travel reverse portT Tank port5 Travel pressure sensor port 6 Travel pressure sensor port P Pilot primary pressure port
PF 3/8
PF 1/4
73.5 5{7.5 0.5}
36.3 2{3.7 0.2}
Model 07291-0000 Primary pressure 50kgf/cm, ( 711 PSI)
Secondary pressure 5.5 ~ 24 kgf/cm, ( 78 ~ 341 PSI ) Rated flow 10 L/min Weight Approx. 11 kg
HYDRAULIC COMPONENTS
Dynamic Acera 01/04-MCPage 5-30
5. ConstructionHYDRAULIC COMPONENTS
Code Name Qty.Torque
Nm {kgfm}Code Name Qty.
1 Orifice (Shim) 4 22 Spring 4
2 Seat 2 15 {1.5} 24 Plug (PF 1/8) 3 9.8 {1.0}3 Orifice (Shim) 4 25 Plug (PF 1/4) 3 25 {2.5}4 Spool 4 26 Socket bolt (M10 x 60) 2 59 {60}5 Body 1 27 Flange bolt 4 5 {0.5}6 Stopper 4 28 Setscrew (M8) 4 15 {1.5}7 Spring 4 29 Washer 4 8 Spring 4 30 Washer 2 9 Name plate 1 31 Rivet 2
10 Shim (t = 0.2) 4 32 Pin ( 5) 4 11 Shim (t = 0.1) 4 33 Ball 6 12 Cam 2 34 Ball 4 13 Boot 2 35 Ball 4 14 Pin 2 36 Ball 6 15 Cover 2 37 U-packing 4 16 Piston 4 38 O-ring (1A P5) 4 17 Guide 4 39 O-ring (1A P24) 4 18 Sleeve 4 40 O-ring (1A P26) 4 19 Holder 4 41 O-ring (1B P8) 3 20 Ring 12 42 O-ring (1B P11) 3 21 Orifice (Shim) 4 44 Piston Assy 4
Apply Locktite #262 to
TorqueNm {kgfm}
Travel pilot valve
Dynamic Acera 01/04-MC Page 5-31
6. OperationsThe pilot valve is made up of the followingsections in the functions.A. Damper sectionB. Reducing valve sectionC. Shuttle section
A. Damper section The primary pressure is fed through the
P port, and flows into the damperchamber through passages (D) and(E).
In addition, the primary pressure isstored in the damper chamber throughthe orifice and check valve.
Then, the air stored in the damperchamber is discharged to T portthrough passages (F) and (G) toprevent the damper performance frominstability due to the entry of air.
If the cam actuates while travelingbecause the oil in the damper chamberis prevented from reversing with thecheck valve, the oil flows to passage(E) through only the orifice section.
The damping operation is performedby the resistance generated when theoil passes through the orifice.
The upper and lower bores of pistonare 12 and 11 respectively, causing thedifference of area, therefore the upwardmoving force always acts on the piston.
Consequently, the cam operation andthe piston on the other side rise due tothe pressure caused by the differenceof area, resulting in the condition whereit follows the cam operation.
Therefore, the damper operation isconstant even the cam is located onany position.
HYDRAULIC COMPONENTS
Dynamic Acera 01/04-MCPage 5-32
B. Reducing valve(1) At neutral position The primary pressure fed through P port
is blocked by the sealing function on theoutside of spool and the hole on the body.
And, since the secondary pressure port isconnected to the T port through vertical hole(H) at the center section and side hole (I),the pressure is zero.
(2) In operation If the cam inclines in the operating
direction, the piston lowers. Since the cutout (J) on the outside of spool
is connected with the secondary pressureport, the primary pressure fed through Pport flows to the secondary pressure port.
Then, the side hole (I) goes in the hole onthe body and is sealed, and the circuit fromthe secondary pressure port to the T portis blocked.
When the pressure at the secondarypressure port rises higher than the forceof spring for the secondary pressure, thespool is pushed up and the cutout (J) goesin the hole on the body and the passagebetween the primary pressure port and thesecondary pressure port is blocked.
And, side hole (I) is connected with the Tport to release the pressure at thesecondary pressure port to the T port.
By repeating the above procedures, it ispossible to obtain the pressure at thesecondary pressure port which is well-balanced against the load of spring for thesecondary pressure corresponding to thecam operation.
The return spring acts to maintain theproper operating reaction force and tosecurely return the pressure reducing valveto the neutral position.
C. Shuttle section If the pressure is produced on the ports 1
and 3, the ball is pressed against the seat. And, the pressure flows from the port 1 to
the port 5 or port 3 to port 6. Only a little pressure leaks from the ports
HYDRAULIC COMPONENTS
Dynamic Acera 01/04-MC Page 5-33
7-10 Solenoid/Proportional valve block1. Appearance
2. Specifications
Code Size Torque: Nm {kgfm} P1, P2, T A1 PF 3/8 74 5 { 7.5 0.5} A2 ~ A8 PF 1/4 36 2 {3.7 0.2}
Port
HYDRAULIC COMPONENTS
ProportionalSolenoidValves
On/
OFF
On/
OFF
On/
OFF
On/
OFF
Note : A1 ~ A8 are Non - Adjustable
Specifications8KWE5G30 / G24WR804 B
0 ~ 50 kgf/cm {0~711 psi}10 kgf/cm {142 psi} or lower
Sol. valve: 16 L/min,Propo. valve: 10 L/min (per one spool)
Rated voltage DC24V Range of allowable voltage 20.4 ~ 30V Rated power consumption 17W or less (at 24V, 20C) Duty 29V continuous (with surge killer) Coil resistance 34 ~ 40 Rated current 700mA Coil resistance 17.5 (at 20C) Range of secondary press 0 ~ 2.9 MPa {0 ~ 30 kgf/cm} Dither in use 100 Hz/300mAP-P {at 300mA}
Item
Proportional valve - Variable
Type Rated pressure (P port) Allowable back press. (T port)
Max. flow rate
Solenoid valve - ON/OFF
Dynamic Acera 01/04-MCPage 5-34
2. Structure
3. Hydraulic diagram
HYDRAULIC COMPONENTS
Code Name Qty. Code Name Qty.101 Casing 1 601 Propo. valve (KDRDE5K-31/30C40-101) 4 151 Plug BP1/16 (Meck) 8 701 Sol. valve (KWE5K-31/G24D40) 3 153 Plug BP1/8 (Meck) 1 702 Sol. valve (KWE5K-31/G24Y40) 1 171 Socket bolt (M5 x 12) 16 901 Name plate 1
A1 ~ A8 are Non - Adjustable
Dynamic Acera 01/04-MC Page 5-35
7-9 Swivel joint1. Appearance
2. Specifications
3. Construction
Code Name Qty.1 Body 12 Stem 13 Thrust plate 14 Cover 15 Seal assy 56 O-ring 27 O-ring 18 Socket bolt 29 Socket bolt 4
10 Blank plug 1
HYDRAULIC COMPONENTS
Dynamic Acera 01/04-MCPage 5-36
7-6 Cushioning Mechanism of Cylinder1) Cushioned cylinder
Cushion mechanism is provided so that earth and sand in the bucket does not fall down due toshock produced when extending and retracting piston rod strikes rod cover and cylinder tubewithout reducing the speed. Boom cylinder Rod side Arm cylinder Rod and head side Bucket cylinder Rod side
Operation of cushion mechanism onrod side.
When reaching close to cylinder strokeend, oil in A chamber passes throughpassage B, and flows into tank port (T)at constant speed.
In addition, after piston rod (4) isextended, cushion ring (13) gets into rodcover (14), oil in A chamber is restrictedand passes through passage B and flowsinto tank port (T) resulting in reduction ofpiston speed.
After piston rod (4) extends further,cushion ring (13) gets into rod cover (14)completely, piston speed is reducedwhen oil in a chamber passes throughand piston (5) strikes rod cover (14) thatis, stroke end.
Operation of cushion mechanism onhead side.
When reaching close to cylinder strokeend, oil in a chamber passes throughpassage B, and flows into tank port (T)at constant speed.
In addition, after piston rod (4) isretracted, plunger (4a) gets into cylindertube (1), oil in A chamber is restrictedand passes through passage B and flowsinto tank port (T) resulting in reduction ofspeed.
After piston rod (4) retracts further,plunger (4a) gets into cylinder tube (1)completely, piston speed is reducedwhen oil in A chamber passes through,then piston (5) strikes cylinder tube (1),that is, stroke end.
HYDRAULIC COMPONENTS
Dynamic Acera 01/04-MC Page 5-37
7-6 Cushioning Mechanism of Cylinder -Cont.
HYDRAULIC COMPONENTS
Dynamic Acera 01/04-MCPage 5-38
7-6 Cushioning Mechanism of Cylinder -Cont.