design project- helper coil spring syspension.pptx

automobile

1. DESIGN OF COIL HELPER SPRING FOR LEAF SPRING SUSPENSION SYSTEM Presented by R.MOHANRAJ

2. ABSTRACT The use of heavy vehicles for carrying goods gets developed more nowadays , but the load carrying capacity differs for each and every vehicle. But the suspension system is especially meant for absorbing shocks and impact loads. We got a result of common failures in front leaf suspension system, particularly in the master leaf ends and together analyzed. To overcome this failure of leaf spring, this project DESIGN OF COIL HELPER SPRING FOR LEAF SPRING SUSPENSION SYSTEM is a part of front leaf suspension system design for heavy vehicles by the use of coil helper spring. This will be the first ever coil spring attachment in front axle of the heavy vehicles.

3. SUSPENSION SYSTEM A suspension system plays a number of roles. It stabilizes the truck when traveling over smooth highway as well as over rough terrain. It cushions the chassis from road shock and enables the driver to steer the truck. It maintains the proper axle spacing and alignment. It provides a smooth ride when both loaded and unloaded

4. LEAF SPRING SUSPENSION A leaf spring is a steel plate or stack of clamped steel plates. Most leaf springs used in trucks today are manufactured from spring steel. Spring steel is middle-alloy steel that has been tempered, that is, heat-treated. The result is to provide a leaf spring plate with considerable ability to flex without permanently deforming. Leaf springs may consist of a single leaf or a series of leaves clamped together, known as a spring pack.

5. COIL SPRING SUSPENSION The helical spring are made up of a wire coiled in the form of a helix and is primarily intended for compressive or tensile loads. The cross-section of the wire from which the spring is made may be circular, square or rectangular. The two forms of helical springs are compression helical spring and tension helical spring. Common one used in automobile suspension is compression helical spring.

6. LEAF SPRING FAILURE ANALYSIS Fails when the load is maximum Fails at the master leaf corners Stress concentration is more at the ends

7. OBJECTIVE OF THE PROJECT By implementing the coil spring as a helper spring in front leaf suspension system. This coil helper spring is to split up the transmitted loads reduce the breakage of leaf springs. Increasing life time of leaf spring It involves the work associated in minimizing the energy absorbed by the suspension while travelling and loading of goods.

8. REASON FOR COIL SPRING AS A HELPER SPRING These are easy to manufacture. These are available in wide range. These are reliable. These have constant spring rate. Their performance can be predicted more accurately. Their characteristics can be varied by changing dimensions.

9. MATERIALS FOR OPEN COIL HELICAL COMPRESSION SPRINGS

10. DESIGN CALCULATIONS Leaf spring suspension without helper coil spring suspension: Max permissible stress (failure stress) on the full length leaves is Max permissible deflection (failure deflection) on the full length leaves is  

11. Leaf spring suspension with helper coil spring suspension Deflection by the Coil Spring  

12. Shear stress acting on the coil helper spring Overall result of suspension system: Reduction in deflection by the implementation of coil helper spring  

13. FINAL ARRANGEMENT

14. DETAILED VIEW OF THE FINAL SETUP Part No Part Name Total Qty 1 Chassis 1 2 shackle 2 3 Bolt set(shackle) 6 4 Supporting bar 2 5 Main leaf 2 6 Supporting plate 1 7 Upper cup 1 8 Coil spring 1 9 Lower cup 1 10 Graduated leafs 10 11 Bolt 2 12 Washer 2 13 Nut 2

15. ANALYSING USING ANSYS Deflection analysis Stress analysis

16. conclusion F rom this concept of suspension system, the coil spring arrangement in the leaf spring suspension system increases the life time efficiency of the leaf spring compared to normal springs and reduces the total vehicle deflection. And also produces smooth running on on/off road conditions.

17. references Manual on Design and Application of Leaf Springs, SAE HS788, Society of Automotive Engineers, Warrendale , PA, April 1980. “Result of very high cycle fatigue test on helical compression springs”. C.Berger , B. Kaiser. 27 th June 2006. “Failure modes of mechanical springs”. William H. Skewis . “Failure analysis of passenger car coil spring”. S.K. Das, N.K.Mukhopadhyay , B. Ravi kumar , D.K. Bhattacharya. 28 th Feb 2006. “Design and failure modes of automotive suspension springs”. Y. Prawoto , M. Ikeda, S.K Manville, A. Nishikawa.21 st feb 2008 Automobile engineering by R.S. Khrumi . A textbook of machine design by R.S kurumi . Machine design by S.M Jalaudin . Design data book by PSG College of technology .