VCT Engine Technology

Introduction of Variable Compression

Turbo Engine

Yutaka Fujimoto

Nissan Technical Center N.A. September 28th 2016

1. Approach for Sustainability 2. Whats Variable Compression Turbo ? 3. All Technical Features of VC-T Engine 4. Performance of VC-T Engine

Contents

: NASA earth observatoryhttp:/ / www.nasa.gov/ vision/ earth/ environment/ arcticice_decline.html

Energy Saving GHG Reduction

Driving Pleasure Affordable Price

Requirements for Sustainability

Compliance

Attractiveness

Approach for Sustainability

2. Electrified Vehicle LEAF

12V 5 48V

Idle stop/Coast stop E recovery/Torque assist

1. Conv. PT improvement

24kWh From 2012

Future

30kWh From 2015

Variable Compression Turbo (VC-Turbo) Engine

EM

High thermal efficiency High performance Clean emission

Non Turbo

Turbo DST VCR Power

Turbo DST

A B C D

Compression Ratio

10-13 8-9 10-11 814 Variable

Fuel Economy = - + ++ Performance = ++ + ++ Emissions = = = ++

Fuel Economy

Perf

orm

ance

Non-Turbo

(Base)

Power-Turbo

DST

DST with VCR

A

B

C

D

Better

Bet

ter

10% V6 3.5l

30%

10%

120 kw

150 kw

200 kw

28 MPG

24 MPG

20 MPG

Contribution of compression ratio optimization


Contents

Compression ratio is quite important spec. for designing engine characteristic.

Bottom

Piston

Top

Bottom

Piston

Top

: 1

:14

: 1

: 8

High Compression Ratio

Low Compression Ratio

Pros

Enabling high charge

Low S/V Fast Cat light off

High Efficiency

Clean Emission

High Performance

High Thermal efficiency

Compression Ratio

Cons

Low Thermal

efficiency

High emission

Variable Compression Turbo Conventional Engine

Mechanism of VC-Turbo

World first mass production engine with variable compression ratio technology Variable compression ratio is achieved by the new multi

link system

Control Shaft

Crank shaft

Piston

Connecting Rod

Upper-Link

C-Link

Lower-Link

2nd Balancer Shafts

ACTUATOR MOTOR

A-LINK


Mechanism of VC-Turbo

World first mass production engine with variable compression ratio technology Variable compression ratio is achieved by the new multi

link system

High CR T.D.C. Low CR T.D.C.

High CR B.D.C. Low CR B.D.C.

Compression ratio can be changed by control shaft angle and link position.

Principle of Variable Compression Ratio

Principle of Variable Compression ratio

High CR: 14 Low CR: 8

Upper-link

Control shaft

Lower-link Crank shaft

ACTR Arm

Piston

ACTR Motor &

Reduction Gear

ACTR Arm



This is actuator moving animation without engine running for easy understanding



VC-Turbo is controlled by calibration map on Engine Control Module according to drivers accelerator pedal operation.

VC-Turbo Control Strategy

Accelerator Pedal ECM

Compression Ratio Map

Target Compression ratio

Engine

VCR Actuator

Sensor


Contents

All Technical Features of VC-Turbo

Conventional technology New technology

Other Engine technologies contribute to achieve further dynamic performance and fuel economy

MPI+DFI SYSTEM

Variable Displacement oil Pump Fuel economy Performance Emission Regulation

DFI is good for more power due to Heat absorbing effect by fuel vaporization. MPI can reduce PN, PM emission. MPI+DFI system contributes also fuel economy by utilizing

each strength.

Multi Port Injection

(MPI)

Direct Injection

(DFI)

MPI+DFI SYSTEM

MPI+DFI

DFI

Engine speed

Eng

ine

load

Conventional Engine

Combustion force

Thrust force

No Thrust force

VC-Turbo

Because angle of Upper-Link is almost vertical, thrust force on cylinder bore can be reduced. Good for Friction

Variable Compression Turbo

1.5

1.0

0.5

0 TDC BDC TDC BDC TDC

Crank Timing

Pist

on f

rict

ion

loss

(kw

) Conv.

VCR

2000rpm, Pmax= 5MPa

Friction reduction 44%

Combustion stroke

Profile of Piston Friction loss

VC-T

FEV scatter band of FMEP vs BMEP at Max power

Good

(Frict

ion)

(Power)

Friction Reduction

1. Approach for Sustainability 2. Whats Variable Compression Turbo ? 3. ALL Technical Features of VC-T Engine 4. Performance of VC-T Engine

Contents

Fuel Economy Outstanding FE with top level Acceleration Performance Approx. 30% FE improvement compared with V6 3.5L Engine

360 380 400 420 440 460 480 500 520 Performance Index

A

Good

Competitor 2.0L DST

0

12

14

16

18

20

22

24

26

V6 3.5L 200kw, 350Nm

X

X

2L T/C Technical sensitivity

28

+10%

B C

VC-Turbo =814

Engi

ne F

uel E

cono

my

+30%

Small Turbo Lag

Accel. Pedal ON

Good Torque Feel Good Stretch Feel

Acceleration G - T curve (standing start, WOT)

Acceleration Segment top level acceleration performance Good Torque and Stretch Feel

VC-T

DST A

DST B

Competitor

Competitor

Emission Performance VC-T Engine can use lower compression ratio during cold

condition to improve emission performance Lower compression ratio contributes as follows

Lower Engine Out HC emission level due to small S/V ratio Quick catalyst warm up from higher exhaust gas

temperature Lower PN emission

7 8 9 10 11 12 13 14 15

Emis

sion

lev

el

Compression Ratio [-]

PN

HC

HC

*Cold condition

NVH With the multilink mechanism, piston motion achieves ideal

sine wave, resolving the unbalance. 2nd order balancer shaft is not necessary This enable low vibration property of in-line 4 cylinder

engine close to that of V6 engines.

Pist

on

stro

ke

Crank angle

TDC

BDC

Rapid VC-Turbo

Slow

Conventional

Conv. L4 VC-Turbo


VC-Turbo achieves good vibration level

Summary Variable Compression Turbo(VC-T) is one of the key

technologies to meet future requirements with sustainability

VC-T can be an Ultimate Eco NA engine and High Power

Sport Turbo engine. VC-T technology enables engine to achieve clean emission, good F.E. and attractiveness at the same time.

Conventional technologies can generate synergy in performance improvement with VC-T technology.

Thank you!

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

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