Post on 29-Jun-2018
transcript
Cylinder Deactivation –
A technology with a future or a niche application?
Dave Kehr
Schaeffler Symposium 2014 Dave Kehr 1
First application: Cadillac Seville
1981
6.0L V8 OHV
864
Schaeffler Symposium 2014 Dave Kehr 2
Examples for cylinder deactivation in mass production
2010 2000 1980 1990
5.0L V8
5.5L V8
5.8L V12
3.5L V6
1.4L I4
4.0L V8
6 3/4L V8
6.5L V12
6.4L V8
6.0L V8
3.9L V6
5.3L V8
6.0L V8
5.7L V8
Why the gap?
Schaeffler Symposium 2014 Dave Kehr 3
Operating principal of cylinder deactivation
Engine Speed in rpm
To
rqu
e in
Nm
4-cylinder mode
Engine Speed in rpm
To
rqu
e in
Nm
8-cylinder mode
Road load curve
Lowest
specific fuel
consumption
Constant
specific fuel
consumption
Engine is
operating closer to
lowest fuel
consumption
Schaeffler Symposium 2014 Dave Kehr 4
Fuel consumption improvement potential p
me
0
1
2
3
4
5
6
7
8
bar
10
n 1000 1500 2000 min-1 3000
-20 -18-16
-14
-12
-10-8
-6
-4-2
0
2
46
6
8
8
be in %
Differenz-Kennfeld 1,4l 4Zgegenüber 1,4l 4Z - ZAS
20
18
16
14
12
10
8
6
4
2
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
-20
bra
ke m
ean
eff
ecti
ve
pre
ssu
re i
n b
ar
engine speed in rpm
Benefit for 4
cylinder mode
Benefit for 2
cylinder mode
Theoretical
switching
threshold
Optimum
combustion
1.4L 4 cyl. with 2 cyl. operation
Schaeffler Symposium 2014 Dave Kehr 5
Two different cylinder deactivation strategies
Drehzahlbereich
Direct injection can improve cylinder deactivation NVH
So
urc
e: M
TZ
"T
he
Ne
w A
MG
5.5
L V
8 N
atu
rally
Asp
ira
ted
En
gin
e w
ith
Cylin
de
r S
hu
t-o
ff"
BDC TDC BDC TDC BDC TDC BDC TDC BDC TDC BDC TDC BDC TDC BDC TDC BDC TDC BDC TDC
Traditional Recent
development
Higher combustion pressures
More pressure variation
Lower combustion pressures
Less pressure variation
Schaeffler Symposium 2014 Dave Kehr 6
Switching strategy – managing torque change
Ignition angle-
efficiency
Actu
ato
r sh
ifti
ng
Filling- target
Actual filling
4 Cyl. Mode Switch-over phase Time 8 Cyl. Mode
En
gin
e To
rqu
e
Cylinder filling (Throttle position)
Sourc
e: M
TZ
Sourc
e: M
TZ
The n
ew
Audi V
8 T
FS
I E
ngin
e P
art
2
Working principle
Schaeffler Symposium 2014 Dave Kehr 7
Switchable finger follower
Valve train with switchable
finger follower and hydraulic
support element
Schaeffler Symposium 2014 Dave Kehr 8
Switchable finger follower
Full lift mode
Deactivation mode
Oil supply
Exhaust Intake
Exhaust Intake
Schaeffler Symposium 2014 Dave Kehr 9
Switchable pivot element
Working principle
Oil supply
Intake
Exhaust
cyl 4 cyl 2 cyl 3 cyl 1
Schaeffler Symposium 2014 Dave Kehr 10
Controlled oil circuit layout
cyl 4 cyl 2 cyl 3 cyl 1
Switching window
independent VCT
Switching window
up to 180° (cam)
Simple oil galleries
Switching window
up to 250° (cam) -
VCT Influence
Cylinder selective
Compact oil
galleries
Oil circuit design Advantages
Para
llel
Cylin
der
sele
cta
ble
Intake
Exhaust
Schaeffler Symposium 2014 Dave Kehr 11
Variable valve lift by cam shifting system (2-step)
Cylinder- and camshaft selective
variability
Provides OBD signal
Can be upgraded to 3-step
(modular principle)
System Advantages
Title
Schaeffler Symposium 2014 Dave Kehr
Chapter
Variabilität durch Schiebenocken-
System (2-Stufigkeit)
- Zylinder- und
nockenwellenselektive Variabilität
- OBD-Signal "aktiv/integriert"
ausbaufähig zur 3-Stufigkeit
(Baukastenprinzip)
12
Schaeffler Symposium 2014 Dave Kehr 13
Electro-hydraulic valve train systems
Uniair-System
Fully variable Lift
Zero lift capable
Provides OBD
signal
Advantages
Schaeffler Symposium 2014 Dave Kehr 14
Fuel consumption improvement potential using CDA
Number of Cylinders per Engine
Fu
el C
on
su
mp
tio
n R
ed
ucti
on
in
%
8 6 4 3
15
8
5 4
Schaeffler Symposium 2014 Dave Kehr 15
Final thoughts
We offer the right components…
…for fuel efficient technology
By failing to prepare,
you are preparing to fail
” ‟
Benjamin Franklin
1706 – 1790