ehvs

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Elektrohydraulische Ventilsteuerung EHVSElectro-hydraulic Valvetrain System EHVSFPNI Forum 2004, Bad Ischl


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Electro-hydraulic Valvetrain System EHVSFPNI Forum 2004, Bad Ischl

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1. Why a hydraulic solution?

2. How does the EHVS work?

3. What components are used?

4. What results can be measured at the test bench?

5. Next steps?

Agenda


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Electro-hydraulic Valvetrain System EHVSExpected Advantages for Gasoline Engines

Fuel consumption/Efficiency Minimization of gas exchange losses (‚dethrottling‘, with manifold injection) valve cutoff, cylinder cutoff, multi stroke operation Reduce of idle speed (more stable due to less residual gas)

Torque curve/Power Operating-point-dependent optimization of valve timing and stroke

Additional functions more efficient engine brake new starting strategies less assembly groups reduced size of the engine

Exhaust gas Operating-point-dependent variation of the charge motion Variable internal exhaust gas recirculation (EGR)

103 408 144


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Electro-hydraulic Valvetrain System EHVSRequirements to a fully variable Valvetrain

103 635 442

• The simultaneous and uncoupled optimization of the fuel consumption andthe emissions requires the independent control of fresh mixture, residual gasand charge motion. For this the opening and closing angle and the stroke ofthe individual gas exchange valves are to be controlled cycle to cycleconform.

• The system‘s fail safety, especially the fail safe position „gas exchange valveclosed“, is to be considered in the system‘s design.

• In order to achieve a low-cost serial production with a high number of piecesthere is to be aimed a use of the control principle as well as the partialcomponents with all known engine types and combustion concepts.

• All material, partial components and production processes necessary for thesystem‘s assembly are to be selected in compliance with the criterionsavailability and process safety.

• The different engine types which are all to be covered with the sameprinciple require a broadly applicable range relating to the parameters„force“, „stroke“ and „valve velocity“.


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Titel des Kapitels

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parameter‘s combination:high force (>1000N), velocity (2,5ms/10mm), stroke (>10mm)

valve velocity and braking behavior adapted to operating point

valve free travel is not always to be assumed

cylinder head with actuators, checkable as moduleafterwards installation of the whole module on the engine block

exchange of individual actuators installed on the mounted cylinder head

temperatures between -40°C ... 140°C

Electro-hydraulic Valvetrain System EHVSSpecification


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Electro-hydraulic Valvetrain System EHVSTechnology Decision

103 448 149

flat seatvalve

cylinder rotaryvalve

ball valveflat rotary valve

gasexchange

one 3/3 solenoid valve two 2/2 solenoid valves servo solenoid valve

pendulum systems linear systems

camless valve trainsystems with cam

single acting plunger,counter spring

double acting plunger(identical surface)

differential-plunger

electro-magnetic

electro-hydraulic

pneumatic piezo-electric

magneto-strictive

electro-motive

electro-hydraulic

electro-magnetic


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5. Next steps?

Agenda


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Electro-hydraulic Valvetrain System EHVSOperating Principle of the Differential Piston

IO IC

open

closed Time

Stroke

closed Time

opening hold closing

Valve brake

closed

open

Time

MV 1 MV 2

MV 1

Gas exchange valve

Gas exchange valve

MV 2

Control for big stroke of gas exchange valve

Control for small stroke of gas exchange valve

Gas exchange valve‘s stroke depending on the control MV1/MV2

103 449 149


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Electro-hydraulic Valvetrain System EHVSHydraulic Principle of Actuator V0.7

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Every actuator includes:2/2 solenoid valve currentless closed athigh-pressure side

2/2 solenoid valve currentless opened atlow-pressure side

Throttle for valve brake adjustable viapilot pressure (-> variable valve brake)

two-stage differential piston drive

hydraulic length compensation

Every actuator can be:assembled or disassembled individuallyat the engine

completely connected hydraulically viathe bearing surface

Actuator

HD rail ........ High pressure supply (50 - 200bar)ND rail ........ Low pressure supply (<5bar)SP rail .........Pilot pressure supply (5 - 20bar)MV1/MV2 ... Solenoid valves

HPV ......... High pressure pump for valvetrain systemDRV .........Pressure control valve for pilot pressureRB ........... adjustable valve brakeGWV.........Gas exchange valve

103 611 350

ND-Rail

HD-Rail

HDV

MV1MV2

GWV

RBSD-Rail

DRV


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Electro-hydraulic Valvetrain System EHVSMeasured Valve Lift Curves for Actuator V0.7

Variation of brake

Pressure: 100 barOil temp.: 82 °C

Measured velocities:v_maxopening: 3,0 m/sv_maxclosing: 3,2 m/svbrake: 0,05 .. 0,5 m/s

(inlet valve)

-0.50.00.51.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.5

10.010.511.0

mm

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

ms

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103 617 350


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Electro-hydraulic Valvetrain System EHVSMeasured Valve Lift Curves for Actuator V0.7

Cycle/cycle jitter

Pressure: 200 barOil temp.: 86 °CNumber of cycles: 50

Measured velocities:v_maxopening: 4,5 m/sv_maxclosing: 5,2 m/svbrake: 0,55 m/s

(inlet valve)

-1

0

1

2

3

4

5

6

7

8

9

10

11

12mm

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

ms

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103 618 350


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5. Next steps?

Agenda


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Electro-hydraulic Valvetrain System EHVSDescription of the System (4V Combustion Engine)

103 600 341

Signals forrpmpedal positiontemperaturescrankshaft position

EHVS- actuator

oil filter(inflow of engine‘s oil circle)

high pressureoil pressure of enginereflowleakage

pressure and temperature sensor pressure relief valve

cylinder head withhydraulic adapter modul,thermodynamic modul

viskosity sensor

high pressure pump

:


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Electro-hydraulic Valvetrain System EHVSEHVS-Actuators, different types

103 627 641

V0.4 (Gasoline Engine)V0.5 (Diesel Engine)

V0.7 (Gasoline Engine)


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Electro-hydraulic Valvetrain System EHVSEHVS-Actuators, different types

103 628 441

V0.4 (Gasoline Engine)V0.5 (Diesel Engine)

V0.7 (Gasoline Engine)

V 0.4 V 0.5 V 0.7

Features - Covers the complete gasoline engine operating range

- Covers the complete diesel engine operating range

- Covers the complete gasoline engine operating range

- actuator can be assembled independently on engine



- valve brake - valve brake - variable valve brake (pilot pressure controled)

- Stand alone test of the cylinder head possible



- high forces during complete stroke - two-stage differential piston drive

- hydraulic length compensation

- uses common engine valves

Size (LxWxH) 98 x 38 x 83 mm 99 x 38 x 87 mm 86 x 36 x 83 mm

Moved mass 76 g 103 g 75 g

Max. (usable) stroke 10 (8) mm 10 (8) mm 12 (10) mm

Opening force (200bar) EV: 835 N; IV: 400 N EV: 1360 N; IV: 670 N EV: 1690 N; IV: 840 N

Closing force (200bar) EV: 475 N; IV: 480 N EV: 765 N; IV: 960 N EV: 450 N; IV: 450 N

Max. Opening speed (200bar) EV: 4,8 m/s; IV: 4,8 m/s EV: 4,0 m/s; IV: 3,8 m/s EV: 4,4 m/s; IV: 4,5 m/s

Max. Closing speed (200bar) EV: 2,4 m/s; IV: 4,2 m/s EV: 2,2 m/s; IV: 3,8 m/s EV: 5,0 m/s; IV: 5,2 m/s


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Header of sectionElectro-hydraulic Valvetrain System EHVS4 Cylinder Head

Cylinder head with:- EHVS actuator- Adapter module

103 596 349


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Electro-hydraulic Valvetrain System EHVSSolenoid Valves

MV1currentless closeddelay opening 280µsdelay closing 330µsopening cross-section 3,4mm²pressure compensation: inlet/outletflow compensation

MV2currentless openeddelay opening 320µsdelay closing 380µsopening cross-section 3mm²pressure compensation: inletflow compensation

103 589 349


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Electro-hydraulic Valvetrain System EHVSHydraulic Pump Unit (next generation)

HPV5Axial piston pump 5 pistonsOutput 5 cm³/rev.Max. rpm 6000 1/minPressure range 20-250 bar

103 595 349


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5. Next steps?

Agenda


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Electro-hydraulic Valvetrain System EHVSTest Engine

Test engine:Combustion engine4 cyl.,16 valvesε = 11Peff = 120 kWMd,max = 200Nmε = 11MPFIEuro-Super ROZ 953-way-catalystEU IV, SULEV certificated16 valves with EHVSHydraulic pump integratedHydraulic oil: engine oil 0W40

103 601 348


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Electro-hydraulic Valvetrain System EHVSFuel Consumption (Dyno Results)

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Messungen in Kooperation mit B

MEP

[ba

r]

0

1

2

3

4

5

6

7

8

Engine Speed [rpm]1000 2000 3000 4000 5000 6000

15

15

105

35

20

15

2530

10

5

05101520253035

Fuel Economy Improvement [%]Customer RelevantReduction ofFuel Consumption

EHVS 16-Valve

3 to 17 %Idle 0.31 kg/h

EHVS cylinder deactivation

3 to 35 %NEDC average 17%

NEDC160 km/h

180 km/h

Measurments with: Actuator V0.4Pump HPV7


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Electro-hydraulic Valvetrain System EHVSDyno results at 2000rpm

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Messungen in Kooperation mit

EHVS λ = 1, BSFC Status 09/03:

Fuel ReductionLow Load: - 35% to - 12%

4 Cyl. 2000 rpm / 2 bar: 332 g/kWhCut off 2000 rpm / 2 bar: 305 g/kWh

High Load: - 12% to - 8%2000 rpm / 7 - 10 bar: 241 g/kWh

Increase of max. Load:Base Engine: 10,3 barEHVS Engine: 11,4 bar

220

260

300

340

380

420

460

500

4 6 8 10 12

BMEP [bar]

BSF

C [g

/kW

h]

Base EngineEHVS 16V EHVS Cyl. cut off

EHVS V0.4, HPV7, Full Engine at 2000 rpm

0 2 4 6 8 10 12BMEP [bar] Measurments with: Actuator V0.4

Pump HPV7


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5. Next steps?

Agenda


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Electro-hydraulic Valvetrain System EHVSHydraulic circuit

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Difference EKS / ZKS

Present systemEKS - one circuit system

engine oil / EHVS hydraulicopen hydraulic systemcommon with engine oil

Next systemZKS - two circuit system

closed EHVS hydraulic systemseparate fluidin small portions mixable fluids

plow

Feed pump

Engine oil pump

High pressurepump

= psurrounding

Engine oil pump

High pressure pump

ehvs

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