Valve springs success- ful in AUDI diesel engine - Scherdel GmbH

REPORTS ON RESEARCH AND DEVELOPMENT, MANUFACTURING, MATERIAL TECHNOLOGY AND THE PRACTICAL APPLICA-
TIONS OF ENGINEERING SPRINGS AND ON THE SYSTEMS, MACHINERY AND TOOLING DIVISIONS OF THE SCHERDEL GROUP
Dear reader,
According to Prof. Dr. Bernd
Gottschalk, the President of the
German Association of the Automotive
Industry, the past year
was a good year for the automotive
industry, providing a sound
economic basis. As far as the
SCHERDEL Group is concerned,
I am pleased to report that, despite
increased competition, we
are heading in the right direction.
This is particularly encouraging in
view of the increasing strain on
our budget: e.g. another rise in
the price of materials; customers
cancelling agreed price reductions;
rebates in relation to fixed price
agreements; and a marked increase
in the cost of energy. In
addition to our long-term plans to
ensure continuous growth, it is our
investment in machines and buildings
which enables our committed
staff to achieve success in the
field of innovative products. In order
to meet the growing demands
of the market and to consolidate
the leading position of the
SCHERDEL Group in relation to
metal working, our aim is to continue
presenting new ideas in the
context of a constructive dialogue
with our customers. We can thus
meet with confidence whatever
challenges the future may bring.
With this in mind, I wish you all
the best for 2007!
Walter Bach
Group Managing Director
Valve springs successful
in AUDI diesel engine
Le Mans winner, Frank Biela, on a visit
to SCHERDEL
T
he 2006 Le Mans race included
some outstanding success stories:
for the sixth time Audi Sport won the
classic Le Mans event and, for the first
time in racing history, with a diesel engine.
One small but by no means insignificant
part of the successful diesel
engine is the SCHERDEL valve spring.
In order to ensure the quality of valve
spring required for success in such a
race, an extensive range of equipment
is required in the Development and
Production Divisions. The Development
Division at SCHERDEL has access to
calculation programs for all types of
springs, kinematic calculations and dynamic
simulations. The activities of the
Development Division include not only
extensive materials- and processdevelopment
work but failure analysis
as well. The manufacture of valve
springs is carried out on partially or fully
interlinked installations using a variety
of elaborate production processes.
In the Prototype Shop prototype
springs of all kinds can be made
speedily and flexibly — even in small
lots. Frank Biela, a friendly winner of
the 2006 event at Le Mans, didn't want
to miss the opportunity of visiting
SCHERDEL, the supplier of "his" valve
springs, and so he came along with
Dominik Schraml, one of the young
talents in motor-racing.
During a tour of the works Biela was
impressed not only by the quality of the
production process but also by the staff
and the technical equipment in the Prototype
Shop. The Le Mans winner encouraged
the staff to continue producing
high-quality springs to be used for
winning races in the future too.
SCHERDEL assured him that no effort
would be spared in this respect and
wished him success for the rest of the
racing season.
After some interesting discussions,
Frank Biela set off for America to take
part in the first race with the R10 TDI in
the ALMS series in Salt Lake City.
(Albrecht Busse)
1
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION EDITION 1/2007 E

ASSOCIATED COMPANIES
Data mining optimizes pro duction processes,
giving decision-makers mo re transparency
Zeitsprung, a company which provides new techn ologies for process optimization
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION
2
Dr. Hans Härtl,
General Manager and Head
of Development at Zeitsprung
Intelligente
Prozesse GmbH
Personal details:
Hans Härtl was born in Tirschenreuth
on 30.8.1956.
Marital status: married, 1 child.
After attending primary and secondary
school in Tirschenreuth,
Hans Härtl began studying mathematics
(subsidiary subject:
physics) at the University of
Bayreuth. He graduated in 1984.
He then founded the company
known as ASIBA GmbH (head-office
now in Regensburg), with financial
assistance from the Federal
Ministry for Research and Technology,
based on an application
for a patent. The company develops
software products and distributes
hardware for the field of
graphics.
Sale of company shares, move to
the University of Karlsruhe where
he studied for a doctorate in informatics
(1986 to 1991). From 1992
until 2006 worked with Schott AG:
first of all with Schott Rohrglas in
Mitterteich, then from 2003 with
Schott Glaswerke in Mainz where
he founded a department specializing
in "Industrial IT". In charge of
process-oriented IT systems
throughout the whole concern.
Founding of the company known
as Zeitsprung GmbH & Co. KG in
May 2006, with its head-office in
Tirschenreuth. Aim of the company:
product development and services
in the field of process- and
production-oriented IT ("Manufacturing
Intelligence Software"), with
special reference to small and
medium-sized enterprises. Continuing
close co-operation with
Schott AG.
Hobbies are photography and cycling
in summer; in winter snowboarding.
C
General Manager, Dr. Hans Härtl, and Andreas
Ackermann, Development Manager, analysing
technical manufacturing processes.
omplex production technologies,
in which a large number of interactive
physical and technical parameters
have a decisive influence on the success
or failure of a product, on its quality
or on its profitability in general, often
create great problems for technicians,
managers or company directors in relation
to assessing the success of a project
and making decisions. The newly
founded company known as "Zeitsprung
Intelligente Prozesse" in
Tirschenreuth / Lohnsitz, in which
SCHERDEL GmbH holds an interest,
provides a new type of software technology
which represents a decisive step
forward in the analysis of technical
manufacturing processes and their optimization.
The aim is to minimize productivity
losses, to enhance quality and
to optimize all processes in relation to
cost. Here, Zeitsprung - Intelligente
Prozesse GmbH & Co. KG makes a decisive
contribution to the safeguarding
of production locations. The General
Manager and Head of Development,
Dr. Hans Härtl, is convinced that in the
future, for the first time, his new technology
will provide the management too
with a detailed insight into technical
processes from the businessman's
point of view.
Zeitsprung GmbH & Co. KG focuses
on the cost-effective use of advanced
technologies in the field of knowledge
processing. The object of this "data
mining" is to provide a clear presentation
of production processes which will
help to enhance process stability for
the customer.
Diagram of a production process taking business aspects into consideration.
The aim is to pinpoint the influential
factors, to weight them, and on this
basis to determine the parameters
which provide the best production
results. On this "information platform",
technical processes – in metal working,
for example – can be imaged and in
this way clearly represented, analysed
and optimized. It is thus possible to
combine extremely compact process
operations, even in the real-time range
– for example, force curves in relation
to an automatic punching machine –
with product information such as materials
used, supplier, batch etc. Until
now, combining these different data
fields required an immense expenditure
of time and effort. The new method
means that technical processes can be
depicted with hitherto unequalled resolution
and transparency. The effect can
be compared to that of the new generation
of camera CCDs in digital photography.
The additional information thus
obtained can be used directly to increase
efficiency.
"Traditional" process indices (e.g.
Overall Equipment Efficiency indices for
yield or efficiency) are like the cockpit
of a vehicle – they provide basic data
concerning the efficiency of a production
process and are a prerequisite for
reliable operation. The recording and
documentation of such data is therefore
important. However, this data does not
help us to decide about the direction of
travel. For this we need the kind of
"navigation system" which is provided
by the Zeitsprung technology and which
contains the directional information required
for intelligent route planning. The
strategies thus evolved help us to reach
our destination more efficiently: by indicating
the shortest distance, for example,
and the shortest time; by avoiding
problematic roadworks or production
stoppages, as in the case of "traffic
hold-ups"; or by showing us how to
make a "dynamic detour" round technical
problems.
The appropriate evaluation of a production
process on a Zeitsprung Data
Warehouse is thus equivalent to the
use of a navigation system in a complex
arrangement of routes and variants,
in order to reach our destination
more quickly. Here, the storage of compressed
process parameters provided
by Zeitsprung symbolizes "map material"
for possible ways of proceeding.
Here, as in the case of electronic maps,
the "routes" which a process has actually
travelled are recorded automatically
and divided up into appropriate stages.
These then provide the basic information
for decision-making.
The Zeitsprung technology has
already proved successful in industrial
production processes – in the glass industry,
for example – and has achieved
an immense increase in efficiency coupled
with an optimization of cost. This
provides the newly founded company
with a solid base as demonstrated by
the orders already extending well into
the coming year. (Dietmar Kiermaier)
Like a route planner, the technology
provided by Zeitsprung makes
it possible to decide how the
speed, cost-effectiveness and
quality of production processes
can be optimized.
Traditional process indices provide
basic data concerning the efficiency
of a production process – like
the cockpit of a vehicle.
For more information contact:
Zeitsprung - Intelligente
Prozesse GmbH
c/o Herr Dr. Hans Härtl
Lohnsitz 5
95643 Tirschenreuth
Phone 09631/6005986
Fax 09631/600846
www.z-ip.de
info@z-ip.de
3
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION

COMPANY NEWS
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION
Staff profile
We'd like to introduce staff members
to you who will act as your
contact if required.
Jérôme Quet
Application technology engineer
Jérôme Quet was born on 07.05.
1976 and has been working with
SCHERDEL in Beauvais since
June 2004.
In addition to assisting with the
diversification of the range of
products, he is mainly involved in
the development of new process
technologies at the location in
Beauvais.
This also includes product development
with the appropriate industrialization
and the realization of
improvement methods (5S etc.)
with project handling (APQP). As
application technology engineer
he is also involved in the control
and monitoring of plans for measures
relating to production equipment
and investments, and therefore
has a decisive influence on
rationalization measures and the
reorganization of production divisions.
Mr Quet is unmarried but lives in
a domestic partnership. His hobbies
are music (he is a keen
drummer), swimming and mountain
biking. In addition to playing
badminton in a club he is also interested
in the cinema and do-ityourself
activities.
New ultrasonic cleaning
installation in Beauvais
Record level in cleanliness requirements
I
n order to satisfy the increasing customer
demands in relation to the
quality and cleanliness of technically
sophisticated components, the
SCHERDEL subsidiary, Herckelbout
Dawson, has invested in a new cleaning
installation at their location in
Beauvais, France. The components
are treated by an ultrasonic process
and also with a detergent. This state-ofthe-art
installation has a special monitoring
system permitting traceability of
the components. Defective products
can be reliably identified during the
production process, thus avoiding
problems with the customer.
Cleanliness is a top priority: The new installation
in Beauvais operates under clean-room conditions.
The new cleaning installation was developed
in co-operation with the Fisa
Group, which has been making a name
for itself since 1981 with the manufacture
of ultrasonic cleaning machines for
the automotive, aircraft and electronics
industry, for the manufacturers of optical
appliances and for medical engineering.
The cleaning installation consists
of a water-treatment facility, a
turning unit, digital weighing scales, two
ultrasonic rinsing units (type 1 and 2), a
drying oven, various secondary-treatment
stages and a welding unit for
packaging bags, as well as the special
monitoring software.
In order to avoid soiling from external
sources, "clean-room" conditions were
created: All the technical equipment is
enclosed in a kind of cabin and the staff
wear overalls and a head-covering.
the composition of its mineral salts
plays a crucial part with regard to the
trouble-free operation of the cleaning
installation. A water-treatment facility,
adapted to suit the existing tap-water,
has therefore been integrated. This provides
optimum conditions for co-ordinating
the following factors in the baths:
water hardness, pH-value and concentration
of detergent. Additional important
parameters are composition of materials,
temperature and duration of
treatment, and ultrasonic frequency setting.
Thanks to the experience which
has already been gained here, optimum
settings can be selected for any type of
spring. This also means that the exchange
of fluid required in the installation
can be minimized – a valuable contribution
to the protection of the environment.
The following example shows the outstanding
results achieved:
Customer requirements in
relation to cleanliness:
• 4.00 milligrams of dirt particles per
packaging unit / 10 springs
• former D6 installation using ultrasonics:
2.42 milligrams of dirt particles
per packaging unit / 10 springs
• new ultrasonic cleaning installation:
0.52 milligrams of dirt particles per
packaging unit / 10 springs
As the example shows, the customers'
cleanliness requirements are exceeded
by far. The investment made here is in
line with the standards of the
SCHERDEL Group in relation to innovation
and quality. It guarantees that
the requirements for ISO 14001 certification,
which the Beauvais factory has
had since December 2003, will continue
to be met in the future.
(J. Quet / D. Kiermaier)
4
The quality of the water in relation to

COMPANY NEWS
New development in
CNC free-form milling
Reichenbacher Hamuel co-operates with Technical College in
Coburg and Merkel, the maker of sports weapons
I
n relation to the manufacture of
high-precision gun barrels the firm of
Merkel in Thüringen occupies an important
market position. The rifle stocks
themselves are made of high-quality
wood – an unworked part can easily
cost 400 euros or more – and until
now, on account of their complicated
three-dimensional free form, they have
mainly been shaped by hand. In order
to produce larger numbers economically,
a machine had to be found which
was able to mill this free form completely
in one clamping process, i.e. in
a single operation. Unfortunately, such
a machine did not exist and so Merkel
contacted a manufacturer of special
machines for wood-working, whose
milling machines of various types they
had been using for more than 20 years:
Reichenbacher Hamuel from Dörfles-
Esbach near Coburg, a member of the
SCHERDEL Group. This engineering
company offers a wide range of general-purpose
CNC milling machines for
treating wood, plastics and aluminium.
View of part of Reichenbacher Hamuel's newly
developed rotational milling centre.
The new development is a machine
which breaks new ground internationally
in the complex field of free-form machining
of wooden parts. This machine
with the designation ECO 1712-B
Sprint is a portal milling centre with two
milling machine tables on which, using
dual-channel technology, rifle stocks of
the same or different design can undergo
rotational milling to the required
shape at the same time. The most
During the rotational milling process the 5-axis
unit machines the revolving rifle stock.
striking feature: on the two milling machine
tables the workpieces are
clamped in revolving devices, which
means that, as well as the five machining
axes for each of the two milling
heads, the CNC centre has two additional
axes. These axes (2 x 6) are coordinated
by the control software, thus
making it possible to shape the complicated
free form of the rifle stocks without
any visible transition lines in the
material and with a precision in the
lower tenth-of-a-millimetre range.
In order to shorten the cycle time per
workpiece and thus reduce operating
costs, the ECO 1712-B can provide a
milling feed of 20 metres per minute, at
24,000 revolutions per minute – previously
it was only 10,000 r.p.m. Thanks
to the use of HSK 63-F cones, which
ensure that in addition the tool-holding
fixture is in contact with an end face,
undesirable vibrations are considerably
reduced. This greatly improves the surface
finish of the workpiece.
When editing the production data, the
laser lab of the Technical College in
Coburg uses a scanner and special
software to supply precise data records
of rifle stocks to within a hundredth
of a millimetre.
From the block of wood roughly
shaped by a saw, an unworked
part is produced which then undergoes
the final milling process in
the CNC machining centre.
Photos:
Merkel Jagd- und Sportwaffen
GmbH, 98527 Suhl
5
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION

RESEARCH
Potential of modern spring materials for spring components
subjected to dyna mic stress in the valve train
New engine designs require springs with improved characteristics and enhanced load-bearing capacity
- Choice of material is crucial - paper presented at the conference of the Association of German Engineers (part 1)
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION
Authors:
Dr.-Ing. Hilmar Brödler,
Dipl.-Ing. Wolfgang Stark,
Jürgen Hartmann
SCHERDEL GmbH,
Marktredwitz
Paper presented by Dr.
Hilmar Brödler at the 2nd
conference of the Association
of German Engineers,
"Valve train and cylinder
head", on 25./26.10.2006
in Leonberg
Diagram 1: Summary of valvespring
materials.
M
odern valve-train designs and
increasingly variable factors in
the cylinder head increase the working
load on the various spring elements,
which have to be adapted to meet future
requirements – among other things
and in particular by the use of higherstrength
materials. New materials,
processes and designs are available
and are being used to an increasing extent.
Introduction
The increasingly stringent requirements
relating to the emission and fuel
consumption values of internal combustion
engines, which are associated with
a large number of individual measures,
in particular minimization of mass and
the reduction of power loss due to friction,
as well as the greater demands
made on the dynamics of vehicle movement,
mean an increase in the requirements
relating to the different spring elements
in the valve train. The new
down-sizing concepts – often with supercharged
engines and, in some cases,
combined with high-speed concepts
– call for a valve spring with good dynamic
characteristics and, as a rule, of
the same dimensions or, as the case
may be, even smaller. Rising engine
temperatures due to direct injection
systems, increased metal-cladding of
the engine and various other influential
factors additionally increase the temperatures
which the components have
to withstand. Exhaust-gas soot filters in
diesel engines or additional filters in the
exhaust tract of petrol engines raise the
exhaust counterpressure at the exhaust
valve and necessitate a greater closing
pressure while the dimensions remain
unchanged.
These examples demonstrate how the
various types of spring in the valve train
– in particular the valve springs, springs
for switchable bucket tappets, compression
springs for hydraulic valve-play
compensation, torsion springs and spiral
springs for variable valve-train elements,
as well as springs for camshaft
adjusters and others – are subjected to
ever-increasing stress, while the performance
of the components must be continuously
improved and, in particular,
their weight and dimensions steadily reduced.
In addition to achieving an optimum
component design using modern design
tools, for years now particular attention
has been paid to the materials
used and the ways in which they are
processed, in order to meet the demands
made on the spring elements.
The following is intended to provide a
general idea of the materials currently
in use or in the process of development,
as well as their manufacturers
and manufacturing processes. Reference
is also made to the design requirements
and to the handling of these
materials, as well as to the techniques
and processes used.
Diagram 2a: Relative increases in the price of
valve-spring wire.
Materials
rod-wire manufacturers
Taking the valve-spring as an example,
the following describes the most
commonly used materials. Diagram 1
provides some reference values for
the three material qualities VD SiCr,
VD SiCrV and VD SiCrNiV, given that
the mechanical-technological parameters
refer to wire with a diameter of
3.0 mm.
The three materials SiCr, SiCrV and
SiCrNiV are the valve-spring materials
most frequently used today. These materials,
which are readily available from
various manufacturers, are characterized
by the fact that they are produced
using the Superclean process, i.e. deoxidizing
with silicon, and subjected to
elaborate testing procedures during billet
treatment, rolling and the various
wire-drawing stages. Particularly for
spring elements subjected to a high level
of dynamic stress, these three materials
provide an excellent surface quality
and a very low inclusion rate. The
Superclean process ensures that the
composition of inclusions in the threematerial
system SiO2-CaO-Al2O3 is
regulated in such a way that they are
ductile and therefore produce only a
very slight notch effect in the metal
lattice. In addition, there are specifications
relating to surface-crack detection
to a permissible depth of 40 µm and
relating to the defined depth of partial
decarburization.
The three materials mentioned have
the following characteristics:
SiCr - High-strength standard material
with good ductility and very good crackarresting
ability
SiCrV - Higher-strength material with a
finer structure
SiCrNiV - Super high-strength material
with very good temperature resistance,
particularly suitable for nitration.
In addition to the technical characteristics
of these materials, an important
factor is their cost. The following summary
provides a comparison of the cost
of the individual qualities of material.
The estimated proportion of the use of
these materials is also indicated.
(To be continued) (Dr. Hilmar Brödler)
wire-drawers
Diagram 2b: Estimate of the proportion
of the use of the different
valve-spring qualities in relation to
the total.
Supplier market
Today there is only a limited number
of suppliers who manufacture
these sophisticated materials. Here
we must distinguish between the
rod-wire manufacturers and those
involved in the next stage, the
wire-drawers. Diagram 3 illustrates
the current global situation in relation
to the supply chains – rod-wire
manufacturers / wire-drawers – for
valve-spring wires.
(as of: 10/2006)
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION
6
1)
in the case of nitrated springs a
reduction in setting loss is possible.
7

The whole is more than the
sum of its parts
SCHERDEL Group offers clients an additional advantage
thanks to a wide variety of synergy effects
TECHNOLOGY & PRODUCT DEVELOPMENT - PROCESS OPTIMIZATION - NEWS AND INFORMATION
P
rogress based on tradition.
Maybe this motto sounds a bit
old-fashioned. And of course it
would be if we didn't revitalise it
continuously. We are constantly
striving after progress in all areas.
Engineering
springs
Development and
production of:
valve springs
compression springs
tension springs
disk springs
sleeve springs
torsion springs
retractor springs, constant
force springs and spiral
springs
spring elements for oil
distribution rings
Tools and
equipment
Development /
design /
production of:
punching tools
bending tools
stamping tools
follow-on composite tools
transfer tools
gauges, gripping devices
peripheral equipment for
automatic handling machines
and special machines
Stamping and
bending technology
Stampings and
shaped components:
thickness of material
0.1 - 3 mm
wire shapes: wire diameter
0.1 - 4 mm
Machines
and systems
Development /
design /
production of:
high-speed and portal
milling machines
single-axis and
coordinate tables
linear robots
handling portals
machine-tool
components
special machines for
spring production
This is something we owe to ourselves
and to our customers. Our
aim is to save you time and money,
and present you with new opportunities.
Indeed the above motto
could be changed to: “At
Automation and
control technology
feeder equipment
assembly devices
ZARIAN single and multiaxis
motion systems
control systems for
special machines
KANYA aluminium profile
module systems
Vehicle
components
formed wire springs
vehicle seat frames:
riveted, upset,
clamped, welded
(projection welded,
spot welded,
pressure welded,
MIG-MAG welded)
Surface
finishing
SCHERDEL progress is a tradition”.
This is guaranteed by the potential
available in the individual companies
in the Group and it applies to
all the following divisions:
cleaning
phosphating
powder coating
cathodic electro
immersion painting
Delta “Magni” products
(Delta Tone, Delta Seal)
Connection
technology
Development /
design /
production of:
standard hose clamps
compact hose clamps
prestressed hose clamps
double hose clamps
Research and
development
testing of materials
and components
design and project work
on components, machines
and systems
development of systems
software development
information transfer
specialist tutoring for studies
and degree work
Assembly
technology
Development /
design /
production of:
spring packs for
automatic transmission
spring supports for car tailgates
return springs for variable valvetrain
systems in engines
pre-assembled tambour door
systems with integrated torsion
springs for the furniture industry
8
SCHERDEL GmbH, PO Box 4 40, 95604 Marktredwitz, Germany, Phone: +49 9 23 16 03-0, Fax: +49 9 23 16 03-4 62