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Valve Train Simulation

DIGITAL ENGINEERING AND EVALUATION
3D Virtual Validation Model

In automotive engineering, precision in valve train systems is enhanced through the integration of a 3D Multi-Body System (MBS) valvetrain model. This model simulates valve train dynamics and interactions with synchronous drives accurately, including the effects of hydraulic valve lash adjusters and combustion back pressure. It allows for quick evaluation of design changes on chain dynamics, facilitating rapid optimization.

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A key focus is on Noise, Vibration, and Harshness (NVH) optimization, achieved by using non-circular or irregular pitch sprockets for resonance cancellation. Dynamic valve drive simulations, particularly with MBS springs, show a high correlation with real engine performance, confirming the model's effectiveness in predicting accurate valve train behaviors. This advanced modeling capability accelerates the development of high-performance engines with reduced NVH.

Single Valve Train Model | Multi Mass Spring

​For an accurate simulation of the entire valve train system, it is crucial to physically precise model each single valve train along with all its components and parts

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  • Valve stroke and acceleration were used to compare simulation and measurement.

  • At high speed (8000 rpm) the effect of spring eigen behavior is most important.

  • The detailed acceleration behavior during opening and closing of the valve can only be simulated with a multi mass spring. A simple Voigt-Kelvin approach would not be sufficient. 

Cam shaft dynamic and phaser influence

  • Angle adjustment for intake and exhaust leads to great variation in camshaft excitations

  • Result: Change of phase and amplitude in excitation torque

  • During development procedure adjustment times are not known / partially known

  • Excitation variation also affects dynamics and strength  of valve train parts

Variable cam contour

Shiftable valve trains play a crucial role in optimizing the fuel consumption of combustion engines by enabling variable control of the valve opening times.

 

  • 3D contact model for intake and exhaust cam shaft

  • Shifting procedure is realized within the SIMDRIVE controller structure

  • The shift pin is guided in a real contour to change cam contour 

  • Used for optimized fuel injection or cylinder cut off

  • Force and bending moment analysis of the shift pin

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