Simulation Model
Formerly, all design and testing work on supplier's products was carried out at the premises of the automotive manufacturer. Nowadays, responsibility for the component through to the complete control system lies with the supplier, for this reason the developer of engine components has a team of highly qualified employees in the fields of development and design. They ensure that products are designed to fullfill customer requirements starting with analysis and simulation, through testing to the application itself.Demands on "intelligent" valve trains include
a. Reduced Noise
b. Reducd Friction
c. Reduced Exhaust Emissions
d. Reduced Fuel Consumption.
The overal objective is : - Valve train systems with reduced mass but increased stiffeness.
- Approach : For optimum design of our engine systems, we use state of the analysis and simulation methods, including kinematic and kinetic calculation, finitreee elements anayses, topologiacal optimization and dynamic simulation. Example : In order to verify the design of a rocker arm valve train, we analyse the dynamic behavioour with the aid of an equivalent Multi Body System see image below :
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| Engine Mechanism |
Test Set Up For Dynamic Measurement
This engine components must fullfill customer requirements in relation to function and reability and must thus achieve the highest quality standard. Here too shown the example of analysisi and simulation we usse the most advanced technology : - Engine Test Rigs, Subassembly Test Rigs, Pulsers and special equipment. Example : - For Dynamic Measurement of Valve trains, we use the most advanced laser measuring technology ( see the image ).
Measurement System
0. Incremental encoder or clock/measurement trigger
1. Pressure In Hydraulic Element.
2. Valve Lift
3. Valve Velocity
4. Valve Stem Force
5. Valve Spring Tension
A. Wheatstone Full Bridge
B. DC Force Amplifier
C. Instrumented Load Measuring Points Valve Timing Drives - The 1911 Patent
The Father of the hydraulic valve lash adjustment elemet (1) recalls aspects of history of the internal combustion engine : It was shortly after the invention of the internal combustion engine itself that imaginative inventors focused their attention on gas exchange valve drives controlled by cams. The Frenchman Amedee Ballee aplied in 1911 for a patent for a valve timing drive that he had already designed as a low friction, maintenance free system :
Cam traacking by roller bearing
Automatic, hydraulic valve lash compensation
Direct valve actuation
Camshaft driven direct via gear ratio reduction or short chain.
The grave disadvantage of this valve train arrangement was the so Caller"L" heard engine design. The combustion chamber could not be arranged directly over the piston but extendes to the valve inlets located to the sides pf the cylinders.
It was Quicly recognizes that irregularly shaped compression and combstion chamber arrangements of this type allowed only moderate levels of chombustion effeciently. THe combustion chambers had to be made more compact and arranged previously gided in the cylinder block came to be located in a "suspended" arrangement in the cylinder head. The camshaft remained at its original position in the cylinder block.
Next followed by the OHV pushrod valve trains...for the further development of valve timing drives.
