NMMU - Becker: Full variable valve train on a combustion ... - DAAD

<strong>Full</strong> <strong>variable</strong> <strong>valve</strong> <strong>train</strong>
on a combustion engine
Faculty of Automotive Engineering
Department of engines and drive<strong>train</strong>

Index Part 1
• Current situation and trends in the automotive industry
• Advantages of a <strong>variable</strong> <strong>valve</strong> <strong>train</strong>
• Existing <strong>variable</strong> <strong>valve</strong><strong>train</strong> systems
• The test engine BMW K71
• <strong>Full</strong> <strong>variable</strong> <strong>valve</strong> control system of the Ostfalia
1

Project manager
Prof. Dr.-Ing. Udo <strong>Becker</strong>
• Ostfalia UAS
apprenticeship and research
• Department of engine and drive<strong>train</strong>
• Department of vehicle acoustics
• Nelson Mandela Metropolitan University
apprenticeship and research
• Department of engine and drive<strong>train</strong>
• Department of vehicle acoustics
2

Presenters
Dipl.-Ing.(FH) Marc Hochheuser
Ostfalia UAS
Department of engine and drive<strong>train</strong>
Nils Werner M.Sc
Ostfalia UAS
Department of engine and drive<strong>train</strong>
3

Current situation and trends
in the automotive industry
Reference: [1]
4

Current situation and trends
in the automotive industry
Reference: [2]
Emissions%
100
90
80
70
60
50
40
30
20
10
0
1970 1971 1975 1977 1979 1984 1988 1992 1996 2000 2005 2009
Year
CO
HC
NOx
5

Current situation and trends
in the automotive industry
Reference: [3]
Trend 1
low cost cars
6

Current situation and trends
in the automotive industry
Reference: [3]
Trend 2
hybrid and electric cars
7

Current situation and trends
in the automotive industry
Reference: [4]
Trend 3
optimising of existing systems
Downsizing – capacity
– turbocharger
Aerodynamic – cw value
Valve <strong>train</strong> – gas exchange
• stratified charging /
lean-burn combustion concept
• <strong>variable</strong> timing
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Advantages of a <strong>variable</strong> <strong>valve</strong> <strong>train</strong>
• New possibility for the gas exchange
• Improvement of the emissions
• Improvement for the fuel consumption
• Improvement of the engine performance
• Possibility for a non-restrictive intake system
• Dynamic operation over the full engine map
9

<strong>variable</strong> <strong>valve</strong> <strong>train</strong>
power stroke
compression stroke
exhaust stroke
intake stroke
10

<strong>variable</strong> <strong>valve</strong> <strong>train</strong>
11

<strong>variable</strong> <strong>valve</strong> <strong>train</strong>
12

<strong>variable</strong> <strong>valve</strong> <strong>train</strong>
13

Existing technologies
Reference: [5]
Reference: [6]
Reference: [1]
14

Existing technologies
Reference: [1]
• Only for intake systems possible
• Valve control over a magnetic <strong>valve</strong> and
a hydraulic fluid
Disadvantages
• Not possible für high RPM
• Only the intake is <strong>variable</strong>
15

Existing technologies
Reference: [5]
• VANOS is a system between the camshaft
and the chain
• Valve control over the engine oil pressure
Disadvantages
• Only possible to change the <strong>valve</strong> phasing
16

Existing technologies
Reference: [6]
• One camshaft for the intake and exhaust
Disadvantage
• Only possible to change the <strong>valve</strong> phasing
17

K71 engine
Conventional <strong>valve</strong><strong>train</strong>
Reference: [1]
2 Cyl. 4 stroke engine 798cc
Valve control with
• one intake camshaft
• one exhaust camshaft
Valve<strong>train</strong> is powered by a chain over the crankshaft
Camshaft are rigid and not <strong>variable</strong>
K71 Engine [1]
18

K71 engine
Conventional <strong>valve</strong><strong>train</strong>
P in kW
rpm
• At 8000 rpm 6kW of the engine power is used by the <strong>valve</strong> <strong>train</strong>
19

Ostfalia
New full <strong>variable</strong> <strong>valve</strong> <strong>train</strong>
• Valve control with a piezoelectric and a
hydraulic fluid
• full dynamic <strong>variable</strong>, intake and exhaust
• phasing
• lift
• opening time
• lift function
20

spring
piston
hydraulic control unit
• for two <strong>valve</strong>s (in/ex)
• controlled by a servo <strong>valve</strong>
housing
cylinder
23

servo cylinder
2 long holes 4 round holes
24

<strong>valve</strong> head
<strong>valve</strong>
• with controll piston
• tooth structure
piston
tooth structure
26

Dynamic multi body simulation
<strong>valve</strong> seat ring
<strong>valve</strong>
hydraulic body
<strong>valve</strong> guide
Illustration of the component material stresses at the <strong>valve</strong> touchdown point
800 rpm
original-
<strong>valve</strong> curve
27

piezo piezo
piston
input
electronic control unit
hydraulic
stroke ratio
servo piston
Hydraulic stroke ratio
• transmission ratio 138:1
Piezo actuator
• P-235.90
• max. 180 µm
28

Valvelift measurement system
Reference: [7]
sensor
7mm x 3.5mm
• high dynamic
• high resolution
• small size
• light weight
• wear system, non tactile
• in real powered engines
possible
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Thank you for your attention
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References
[1] http://benzinpreis.de/statistik.phtml (state: 22.08.2012)
[2] http://www.umweltzone.net/index.php
http://www.umweltauto.at/8.html (state: 02.08.2012)
[3] http://www.innovations-report.de/html/berichte/studien/bericht-
74384.html (state: 23.07.2012)
[4] http://www.fptmultiair.com/flash_multiair_eng/home.htm
(state: 22.08.2011)
[5] http://www.bmw.com/com/en/insights/
technology/technology_guide/articles/vanos_double_vanos.html.
(state: 16.08.2011)
[6] http://www.mahle.com/C125705E004FDAF9/vwContentByKey/W28LJ
FHW726STULEN (state: 23.09.2011)
[7] Sensitec Produktkatalog; (state: 11.12.2011)
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Thank you for your attention
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