This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Dynamic Connecting Rod Bolt Self-Loosening in Internal Combustion Engines
Technical Paper
2010-01-0692
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
As automobile manufacturers continue to strive toward delivering vehicles with the highest possible blend of fuel efficiency, reliability, performance and cost, new engine designs need to be as optimized as possible. A significant barrier to engine efficiency is unnecessary reciprocating and rotating mass in the internal combustion engine, which has driven the advancement of computer modeling and finite element analysis in order to optimize these components. As a consequence of this drive to reduce mass and cost, the safety factor of a component is made as low as possible. When a component is considered optimized for its environment and has a very low safety factor, any unforeseen stresses or strains may cause the part to fail or perform unexpectedly. Such stresses can be caused from engine misalignment, crank throw bending or abnormal combustion phenomenon. This is especially problematic when a supplier of one component that is involved in a dynamic assembly is not able to predict external or unexpected forces caused by other components outside of its range of responsibility.
This is believed to be the root cause for recent dynamic connecting rod bolt self-loosening issues, which caused multiple engine failures during durability testing. A thorough investigation was conducted that relates the broader issue of fastener self-loosening to the specific example of the internal combustion connecting rod bolted joint. Through empirical evidence, firing engine measurements and analysis, the theory of bolt self-loosening in the connecting rod bolted joint is presented. Additionally, a new machine has been developed that accurately simulates connecting rod bolt self-loosening in a manner similar to the Junkers fastener vibration machine. This paper will also address fixes that can be made with regards to the fastener itself.
Recommended Content
Authors
Topic
Citation
Hall, C., Lapp, M., and Krause, R., "Dynamic Connecting Rod Bolt Self-Loosening in Internal Combustion Engines," SAE Technical Paper 2010-01-0692, 2010, https://doi.org/10.4271/2010-01-0692.Also In
Reliability and Robust Design in Automotive Engineering, 2010
Number: SP-2272; Published: 2010-04-13
Number: SP-2272; Published: 2010-04-13
References
- Junker, G.H. “New Criteria for Self-Loosening of Fasteners Under Vibration,” SAE Technical Paper 690055 1969
- Nassar, S Housari, B. 2007 Study of the effect of hole clearance and thread fit on the self-loosening of threaded fasteners Journal of Mechanical Design. 129 555 564
- Nassar, S Housari, B 2006 Effect of thread pitch and initial tension on the self-loosening of threaded fasteners Journal of Mechanical Design. 128 245 254
- Nassar, S Housari, B 2007 Effect of thread and bearing friction coefficients on the vibration-induced loosening of threaded fasteners Journal of Vibration and Acoustics 129 620 629
- Zhang, M Jiang, Y Lee, C 2007 Finite element modeling of self-loosening of bolted joints Journal of Mechanical Design 129 218 226
- Zhang, M Jiang, Y Lee, C 2003 A study of early stage self-loosening of bolted joints Journal of Mechanical Design 125 518
- Hashimura, S. Socie, D.F. “A Study of Loosening and Fatigue of Bolted Joints under Transverse Vibration,” SAE Technical Paper 2005-01-1320 2005
- Bickford, John Nassar, Sayed 1998 Handbook of bolts and bolted joints New York Marcel Dekker Inc.
- Bickford, J.H. 2007 Introduction to the Design and Behavior of Bolted Joints New York, NY CRC Press
- Braun, B. 2003 Systematic calculation of high duty bolted joints with one cylindrical bolt 2001 Dusseldorf: VDI 2230) Beuth Verlag GmbH
- Schambach, B. Determination of coefficient of friction of bolt nut assemblies under specified conditions 1991 Determination of coefficient of friction of bolt nut assemblies under specified conditions 1 Berlin DIN