DETROIT, Oct. 21 /PRNewswire-FirstCall/ -- Siemens VDO Automotive has
successfully transitioned the world's first piezo-electronic common-rail (PCR)
diesel injection system from the drawing board to the streets during the past
two years. The unique diesel common-rail system is on display this week at
the 2002 Convergence conference on automotive electronics.
Years ahead of the competition, Siemens VDO Automotive already has
produced over 1.5 million piezo injectors since start of high-volume
production in 2001. Since then, the company has received numerous high-volume
contracts from PSA, Volkswagen and other major European vehicle manufacturers.
The use of piezo-electronic actuators in the new common-rail diesel
injection systems from Siemens VDO Automotive is resulting in quieter, lower-
emission diesel engines. Modern injection systems are one of the main reasons
the diesel engine vehicle market is growing so rapidly in Europe. Higher
torque, lower fuel consumption, improved emissions and engine noise all depend
on injection quality.
Two factors, in particular, determine the quality of a diesel direct
injection system: the pressure at which fuel is injected into the cylinder and
the ability to precisely control each individual injection cycle. The Siemens
VDO Automotive piezo common-rail system offers significant benefits addressing
both factors.
A common-rail injection system separates the two functions -- generating
pressure and injecting -- by first storing the fuel under high pressure in a
central container (rail), then delivering it to the individual injection
valves (injectors) only on demand. This ensures injection pressure of up to
1,600 bar is available at all times, even at low engine speeds. The high
pressure produces a fine atomization of fuel that burns more completely in the
combustion chamber. This results in lower fuel consumption and better engine
performance.
Speed is the greatest advantage realized by the Siemens VDO Automotive
piezo injectors. With the PCR system, the switching elements operate much
faster than the conventional solenoid valves, making it is possible to split
the injector fuel volume into as many as five individual injections.
Future engine management strategies could include two pre-injections with
very small volumes of fuel, followed by the main and two smaller post-
injections. The pre-injections serve primarily to build an evenly distributed
pressure in the combustion chamber, thereby reducing noise during combustion.
The post-injections are provided for the exhaust gas post-treatment which can
help reduce engine emissions.
Piezo-electronic actuators are switching elements utilizing the specific
behavior of piezoelectric crystals. When an electric charge is connected to
such a crystal, the crystal lattice changes within a few milliseconds and
expands. Only when the material is discharged does it return to its original
dimensions. The company uses this unique property to control fuel flow in the
injector.
Other components of the Siemens VDO Automotive common-rail systems also
satisfy the very high demands for automotive diesel fuel injection systems.
For example, injector nozzle bores can have a diameter as small as 0.12
millimeters. The permitted manufacturing tolerance for the bores is less than
0.003 millimeters. The high-pressure pump has an efficiency rating up to 95
percent and is volume-controlled.
Siemens VDO Automotive's high-speed precision injectors and common-rail
systems are today positioned to help diesel engine makers meet future European
and U.S. exhaust emissions regulations.
Siemens VDO Automotive is a tier-one supplier of automotive
electronic/electrical systems and components with applications covering
gasoline and diesel powertrain systems, safety and chassis systems, body
electronics and interior and infotainment. Worldwide sales reflecting partial
fiscal year 2000/2001 totaled $5.6 billion.
Siemens AG (NYSE: SI), headquartered in Munich, is a leading global
electronics and engineering company. It employs more than 450,000 people in
193 countries and reported worldwide sales in excess of $72.7 billion in
fiscal 2001 (10/1/00 - 9/30/01).
The United States is Siemens' largest market, with 77,000 employees and
sales of more than $18.9 billion in fiscal 2001. Siemens is a leading
provider of advanced technology solutions in the information and
communications, medical, power, automation and control, transportation and
lighting sectors, and leverages its global network of innovation and
unparalleled technological heritage to deliver business results for Siemens'
customers around the globe. For more information about Siemens in the U.S.,
go to http://www.usa.siemens.com .
SOURCE Siemens VDO Automotive
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Related links:
http://www.usa.siemensvdo.com
CONTACT:
David Ladd, +1-248-209-5822,
david.ladd@siemens.com , or Brad Warner, +1-248-209-5826,
brad.warner@siemens.com , both of Siemens VDO Automotive
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