Hyundai Dash 9 Posi - Nega sytem
Short Description
Description of how the Posi-Negi hydraulic system works on certain Hyundai Excavators...
Description
Hydraulic System R210LC-9
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Pump Assembly Pi1=Neg. Control Pm1=Flow Cut Off Regulator 1
Regulator 2
Pi2=Neg. Control Pm2=Flow Cut Off EPPR Pressure EPPR Valve
P1 Front
35 bar
P2 Rear -2-
Pilot Pump Hyundai Training Center
R210LC-9
1. Main Pump 1-1. Hydraulic circuit
Pi1
Pi2
Horsepower Control Function
Flow Control Function
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R210LC-9
P1
Pi1
P2
Pi2
1)P1,P2 : Main Pump
2)Pi1,Pi2 : Positive control 3)Psv : EPPR V/V
◀
▶
P1
P2
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R210LC-9
Pi pressure-1
Low
High pressure
No work
Low
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R210LC-9
Pi pressure-2
High
Low pressure
Work
High
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R210LC-9
1-2. Check Valve
Pi1
Pi2
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R210LC-9
2. Pump Regulator 2-1. Function-1
1) Horsepower control function (negative system) Power Shift Control Pump self pressure and the other Pump Pressure 2) Flow Control Function (Posi-Nega Flow Control) (Pi1,Pi2) Control Qmax cut-off EPPR Control Horsepower control part Flow Control Part
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R210LC-9
2-2. Function-2
1) Horsepower Control Function (Negative Control)
2) Flow Control Function (Posi-Nega Flow Control) - Pi pressure and Max. Flow cut EPPR. Control
- P1, P2, Pf Control
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R210LC-9
2-3. Regulator Circuit and Structure
Outer spring
Pi
Inner spring
Pf P2 P1
Pf (EPPR)
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P2
P1
Drain
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2-4. Horsepower Control (Negative Flow Control) 2-4-1. Overload protecting function
R210LC-9
When P1,P2 pressure rise up, compensation piston begins to push the rod balancing with spring force. When the hydraulic pressure exceeds the spring force, then hydraulic oil will be supplied to large chamber of servo piston and the pump discharge rate will be reduced.
Cylinder Pressure
Spring Force
(Discharge rate Decrease)
Pf
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Q
rpm
?
HP ∝ P X Q
P - 12 -
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R210LC-9
2-4-2. Recovery of flow
When P1,P2 pressure decrease, the spring force pushing the compensation piston rod exceeds the hydraulic pressure and shifts the compensation piston. Then large chamber of servo piston is connected to tank, that makes pump discharge rate increase.
Cylinder Pressure
Spring Force
(Discharge rate Increase) Pf
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2-4-3. Adjustment of power
②
①
Screw Counterclockwise (Flow ↓)
Screw clockwise (Flow ↑)
① Adjustment of 1st power - Release lock nut of 36mm Screw clockwise (Flow ↑)
- Adjust screw of 24mm ② Adjustment of 2nd power - Release lock nut of 13mm
Screw counter clockwise (Flow ↓)
- Adjust rectangle screw Pressure
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R210LC-7A
2-5. Flow Control Function (Negative Control Function) 2-5-1. Flow decrease - RCV Lever neutral and fine control Pi increase
Pf P2
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R210LC-7A
2-5-2. P-Q Graph (Relation between Pi and Flow)
Pilot flow control Screw
Screw : Counter clockwise (Flow ↓) Screw : Clockwise (Flow ↑) Pi1,Pi2
Flow control by controlling negative pressure (Pi1,Pi2).
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2-6. Flow Control Function (Posi-Nega Control Function)
R210LC-9
2-6-1. Flow Increase - Operating Attachment Pi increase Pf P2
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R210LC-9
2-6-2. Flow Control when operating RCV lever (Relief)
When any of main spools is changed over, the bypass circuit is cut off. The posi-nega conversion valve spool is not shifted. At this time, “PH” pressure discharged from “P3” pump will flow to regulator “Pi1” passing through posi-nega conversion valve and shuttle valve. That will make pump discharge rate increase.
Pi2 (Pump) Pi1 (Pump)
PH
Dr1
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CENTER BYPASS
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2-6-3. Posi-Nega Conversion Valve when RCV Lever is positioned at full position (Relief)
R210LC-9
MCV Center bypass
Pi1 (Pump) Low pressure can’t shift the Spool.
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R210LC-9
2-6-4. Flow decrease - RCV Lever neutral and fine control
Pi decrease
Pf P2
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R210LC-9
2-6-5. Flow Control when RCV lever is in neutral position
When hydraulic oil passing through the center bypass line increases, the posi-nega conversion valve spool moves to the left side. At this time, oil discharged from P3 pump will be blocked and Pc1 will be connected to the drain line, “Dr1”, it makes Pp11 line pressure lower and controls pump discharge flow rate to its minimum value.
PH
Dr1
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CENTER BYPASS
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2-6-6. Posi-Nega Conversion Valve when RCV lever is in the neutral position
R210LC-9
SPOOL shifted to the left
PC
Pi1 (Pump)
PH
Dr
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P
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R210LC-9
2-6-7. Posi-Nega Valve
MCV Center bypass
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R210LC-9
Pilot Pressure and Discharge Rate Curve
Q
Posi-Nega
Negative
5-9
16-19
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Pilot Pressure(bar)
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2-6-8. P-Q Graph (Relation between Pi and Flow)
Pilot flow control Screw
Screw : Counter clockwise (Flow ↑) Screw : Clockwise (Flow ↓) Pi1,Pi2
Flow control by controlling negative pressure (Pi1,Pi2).
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3. Pf (Power shift control by EPPR valve 3-1. Current and Voltage each Mode According to the mode, CPU sends EPPR valve the variable current value. So, swash plate angle is changed.
Eppr v/v pressure and current value by each mode
R210LC-9
R290LC-9
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Q
P
S
P
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R210LC-9
3-2. P-Q Curve
R210LC-9 P-Q curve 2
1900rpm, Pf=0(kgf/cm )
240
2
1900rpm, Pf=2.5(kgf/cm )
220
2
1700rpm, Pf=8(kgf/cm )
200
2
1700rpm, Pf=13(kgf/cm )
180
Q (lpm)
160 140 120 100 80 60 40 20 0 0
5
10
15
20
25
30
35
40
P (Mpa) - 28 -
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R210LC-9
3-3. E/G RPM recovery by EPPR valve
E/G
PUMP rpm
EPPR
Unload: 1,950rpm Initial: 185mA, 2.5kg/cm2
↓ load : 1,900rpm
EPPR increase
P CPU S cluster Page 29
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4. MCV
R210LC-9
4-1. Spool Position-1
⑨⑧
⑦
② TRAVEL LIFT SPOOL
⑩ ⑪ ⑫
① TRAVEL STRAIGHT SPOOL
⑥
④
③
②
③ BOOM-1 SPOOL
①
④ BUCKET SPOOL ⑤ ARM-2 SPOOL
⑭
⑥ TRAVEL RIGHT
⑤
⑦ SWING SPOOL
⑭
⑧ SWING PRIORITY SPOOL ⑨ BOOM 2 SPOOL
⑮
⑩ OPTION SPOOL ⑪ ARM 1 SPOOL ⑫ BYPASS CUT SPOOL ⑬ BYPASS CUT SPOOL ⑭ HOLDING VALVE ⑮ ARM2 LOGIC VALVE
⑬
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R210LC-9
4-2. Spool Position-2
(31) Swing Logic Valve (32) Arm-Port Relief Valve (37)(36) Posi-Nega Valve (35) Arm Logic Valve
(32)
(34)
(34) 2-Stage Option Port Relief Valve
(35)
(33) Option Port Relief Valve
(36)
(31)
(33) (37)
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4-3. Spool Position-3
R210LC-9
Px : Attachment Auto Idle Switch Py : Travel Auto Idle Switch (41) : Bucket Limit Stroke
Py (41)
Px PG
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4-4. Sensor Position-3
R210LC-9
Sensors Position
Pilot Control Swing, Boom Up, Arm In/O ut/Bucket In : 50k, 3EA
Auto Idle Signal Px , Py (The Lateral Face of MCV) : 50k, 2EA
Positiv e Control Pc1 & Pc2 : 100k, 2EA
Main Pump P1 & P2 : 500k, 2EA
Pilot Pump P3 : 50k, 1EA
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4-5. Pressure Sensor Specification (Output Signal vs Pressure) (Electrical Signal from Pressure Switch to CPU)
50 bar Pressure Sensor ( P/NO : 31Q8-40520 )
● ●
V (Voltage)
●
bar ●
100 bar Pressure Sensor ( P/NO : 31Q8-40510 )
●
V (Voltage)
●
voltage bar ● ●
500 bar Pressure Sensor ( P/NO : 31Q8-40500 )
V (Voltage) ●
bar
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4-6. Main Port-1
N2
Pc2
N1 Pc1 Ba
PIs Ao
Bo XB2
Dr1 As Atr
Bs Btr
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4-7. Check Valve Position-1
LCa
LCo CCb
XB2 LCs
CP1
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4-8. Main Port-2
Aa(Load)
R2 Ak
Bk
Ab
Bb Btl Py
Atl Py
Pz PX PG
PO PX PG
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4-9. Check Valve Position-2
LCAP2 LCAT2 CRa LCk LCb CRb Py CMR2
C2 CMR1
Pz
PX PG
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4-10. Pilot Port-1
PCV1
XBp1
BaR
XAa1
XAa2
BoR
XAo
Pck
BkR
Psp
XAb1
BbR
XAs
XBtl
XBtr
PTa
Xbk
DR2
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4-11. Pilot Port-2
Pss XBp2
PCV2 PH
XBa2 Pp
XBa1
Dr3 AR
Xak
XBo
AaR
AkR AbR
XBb1 XAtl
Pd AoR
XAb2
XBs
MR XAtr
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4-12. P1, P2, R1 Position P3,P4,P5 -> Plug d1,d2,d3 -> drain
P1
d1 d2 d3 P2
P3
R1
P4
CCk
CCo P5
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4-13. Port Name
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5. Boom up
R210LC-9
*Shuttle
*AM2 logic
BK IN
*Stroke limiter
BM2
BM1
Boom Up has priority over swing/arm/bucket operation - swing logic v/v - arm 2 logic v/v 주행직진
- bucket-in stroke limiter
P1
P2
R210LC-9
6. Boom Priority Function (Swing Logic Valve )
Swing logic valve is for boom priority when Boom up & Swing are operated simultaneously. The swing logic valve does not move in single swing operation.
Manual : Fixed boom priority function Auto : Pressure sensors sense the pilot pressure of boom up & swing. MCU sends the current to boom priority EPPR valve. Then, swing logic spool moves according to boom priority pilot pressure Boom1 spool Boom 2
Swing priority
Swing Logic
P1
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R210LC-9
6-1. Electric Circuit for Boom Priority
BOOM MCU XAb2
XAb1
CN 53-9 Boom Priority EPPR + CN 53-19 Boom Priority EPPR CN 51-2 BATT’ POWER 24V CN 52-23 BOOM UP PRESSURE CN 51-5
PnS (MCV)
GND. PRESSURE
CN 52-24
XBs
XAs
SWING PRESSURE
SWING
▲
Psp
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P3
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6-2. Swing logic valve operation Boom2 Swing spool Swing priority To/From cylinder
Pns
Swing Swing logic
P1 bypass passage
Pns
P1 parallel passage
Pns
When boom priority pressure(Pns) is applied to swing logic valve, P1 parallel passage toward swing spool is restricted. So, boom up operation has priority over swing operation.
Pns
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Pns
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R210LC-9
7. Boom down operation
From cylinder
Check Valve is installed inside the spool for make up function (Boom Regeneration)
To cylinder
Cavitation is prevented by supplying the return oil from the check valve to supply line when the speed of boom down is faster than that by the oil supplied to large chamber of boom cylinder
Boom1
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R210LC-9
8. Arm in Operation
암1 암2
암2로직
암재생 해제sol
암재생cut
P3 P1
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P2
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9. Arm regeneration
R210LC-9
Arm speed control in the cluster On : Power of A4 solenoid will be off. So, Arm regeneration will be started when “pis” is given up. Off : A4 solenoid will be operated. So, Are regeneration will be given up when oil flow to “pis” Posi-Nega V/V
Dr1
Arm CYL. Small chamber
Arm CYL. Large chamber XBa1 XAa1 Arm Regeneration spool
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R210LC-9
9-1. Arm regeneration operation
From cylinder To cylinder
Check valve
P2
Arm1 spool Arm1
Arm P2 regen cut
P1 bypass
Pis
Hole
Arm regen. cut spool
P1
P1 parallel
Pis
Arm regen.
Arm Regen. cut
Pis
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R210LC-9
10. Swing Operation
암1 암2
암2로직
Swing motor RCV lever
P3 P1
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R210LC-9
11. Swing Priority Valve Boom2
If you operate swing, pilot pressure will be supplied to “Psp”. Then, swing priority spool will be moved over and hydraulic oil is supplied to swing motor preferentially.
Swing priority Swing motor
Swing
Swing logic
P1 bypass passage
P1 parallel passage
Boom-up pilot pressure
Swing pilot pressure (Psp)
Boom2 spool
Swing priority valve
To Boom 1 spool (Boom confluence)
P1 parallel passage P1
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(To Arm1/Option spool)
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R210LC-9 X
12. Arm 2 Logic Valve When Boom up is operated, arm2 logic valve blocks the oil flow from P2 pump to the arm cylinder. Arm2
Combined operation of boom up and arm Arm2 logic
Boom up pilot Boom1
P2 parallel Boom up pilot
X
PnA2
P2
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12-1. The Position of Arm 2 Logic Valve
PnA2
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Dr7
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12-2. ARM-2 Spool Pilot Port When an operator operates Arm in or Swing, it carry out positive control through “Pp”
Pss
XAa2
Arm out confluence Pilot
XBa2 Pp Pss
Arm in confluence Pilot To “Pc1”->pump regulator Swing pilot signal
Pss
XBa2 Pp
XBa2
Pp
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R210LC-9
13. Bucket in operation
Bypass cut
암재생 해제sol
암재생cut
P1
P2
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R210LC-9
13-1. Bucket-In confluence
To/From cylinder
P Bypass cut2
Tank
Bucket spool
off spool
BK-in pilot
BK-in pilot
P2 bypass P1 bypass
P2 parallel
P1 bypass
Tank
BK-in pilot
Bypass cut spool 1
P2
P1 bypass
BK-in pilot
Bucket conflux passage
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R210LC-9
14. Bucket Stroke Limiter During the combined operation of boom-up and bucket-in, boom-up pilot pressure moves the bucket spool to half stroke, not full stroke.
Cylinder Stroke limiter
Bucket spool Bucket in pilot
Flow to bucket cylinder is reduced and P2 pump oil is supplied to boom cylinder preferentially.
Boom up pilot (Pck)
Boom up pilot
(Pck) Bucket-in pilot
Stroke limiter spool
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14-1. The Position of Bucket Stroke Limiter
Xbk Xbk Pck
Pck
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R210LC-9
15. Option Attachment 15-1. Breaker Mode At breaker mode, CPU allows the current to ATT’ Flow Control EPPR V/V to reduce the oil flow up to 7 Step.
Max 7 step, reduced 10 lpm each step
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R210LC-9
15-2. Crusher Mode At crusher mode, CPU will send the current to ATT’ Flow Control EPPR V/V and reduces the delivered flow to maximum 4 step. 210 bar → 280 bar
Max 4 step, reduced 20 lpm each step
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15-3. Hyd. circuit
Pi1
④
Bypass cut
① Option Att’ Safety sol. ② Option Att’ pressure sol. ③ Option Att’ conflux sol. ④ Option Att’ flow control v/v ⑤ 2-Stage option relief v/v
⑤
P1
①
③
②
P2
① ② ③
Option pedal
④
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16. Straight Travel Function
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R210LC-9
16-1. Straight Travel Valve(1)
선회우선
“SH” swing parking brake P1
P2
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PG
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R210LC-9
16-1. Straight Travel Valve(2)
선회우선
P1
P2
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PG
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16-3. The position of straight travel straight circuit valve & orifice.
Py PX PG d1 d2 d3
P3
P2
R1 4mm
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R210LC-9
17. Pressure Sensor
선회우선
“SH” swing parking brake P1
P2
PG
When travel and work equipments are not operated with other requirements, auto ilde is activated
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18. Holding Valve Holding Valve is applied both Boom down and Arm In
Pal : Arm holding release pilot port
Pbl :Boom holding release pilot port
CBa : Arm holding Check v/v
CBb : Boom holding Check v/v
Pal CRa
Pbl CRb
CRa CRb
Holding release pilot port
Check v/v Large chamber
From CYL. Chamber (Boom->Large ,Arm->Small)
Dr3(drain)
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R210LC-9
18-1. Holding Condition
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R210LC-9
18-2. Holding Release
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