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
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
1. Approach for Sustainability 2. Whats Variable Compression Turbo ? 3. All Technical Features of VC-T Engine 4. Performance of VC-T Engine
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
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
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
Compression ratio can be changed by control shaft angle and link position.
Principle of Variable Compression Ratio
This is actuator moving animation without engine running for easy understanding
Compression ratio can be changed by control shaft angle and link position.
Principle of Variable Compression Ratio
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
1. Approach for Sustainability 2. Whats Variable Compression Turbo ? 3. All Technical Features of VC-T Engine 4. Performance of VC-T Engine
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
Variable Compression Turbo Conventional Engine
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!
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