Leaf Spring Suspension in detail

Introduction, types, assembly, advantages, disadvantages and application and also related images

1. AEN LCA 5 Leaf spring suspension Name : Aamin Rabkavi Atul Arkhade Adwait Vartak Prathmesh Kulkarni Under Guidance of Prof Ketan Karandikar

2. Introduction A leaf spring is a simple form of spring, commonly used for the suspension in heavy duty vehicles. It is also one of the oldest forms of spring, dating back to medieval times. The center of the arc provides location for the axle, while tie holes are provided at either end for attaching to the vehicle body. For very heavy vehicles, a leaf spring can be made from several leaves stacked on top of each other in several layers, often with progressively shorter leaves. Leaf springs can serve as damping to some extent as well as springing functions. For this reason manufacturers have experimented with mono-leaf springs.

3. Cont.. The standard dimensions for the width and thickness of the leaves section are as follows: Nominal thickness :- 3.2, 4.5, 5, 6, 6.5, 7, 7.5, 8, 9, 10, 11, 12, 14. Nominal width (mm) :- 32, 40, 45, 50, 55, 60, 65, 70, 80, 90, 100 and 125. The leaves are usually made up of steels. The factor of safety based on the yield strength is form 2 to 2.5 for the automobile suspension.

4. Nomenclature

5. Types

6. Tools Required 2 replacement leaf springs Ratchet wrench Floor jack 2 jack stands Penetrating oil Pliers Pry bar

7. Assembly Step 1 : Raise the rear wheels with a floor jack

8. Step 2 : Place jack stands in front of the back tires.

9. Step 3 : Push the car with your hand to make sure it is stable.

10. Step 4 : Use safety glasses & soak the spring’s nuts and bolts in oil

11. Step 5 : Remove the bolt from the shock pads with a ratchet wrench

12. Step 6 : Loosen the U-bolts to remove them

13. Step 7 : Unscrew the eyelet bolts on the spring’s ends

14. Step 8 : Repeat the steps to remove the other leaf spring

15. Step 9 : Position the new leaf spring under the mounting brackets

16. Step 10 : Screw the leaf spring to the front bracket with a ratchet wrench.

17. Step 11 : Attach the spring to the rear bracket

18. Step 12 : Install the U-bolts and shock pad

19. Step 13 : Secure the other leaf spring to the opposite tire

20. Step 14 : Remove the floor jack and you are done

21. Advantages The way the suspension is constructed is really simple and strong, acting as a linkage that holds the axle in position without the need for separate linkage. Extra weight and costs are reduced because of the rear axle location. This eliminates the need for trailing arms and a panhard rod (AKA track bar). Leaf springs support the weight of the chassis, making them ideal for commercial vehicles. They also control axle damping. The chassis roll can be controlled more efficiently due to the high rear moment centre and wide spring base. If the springs are mounted wider apart, the roll tendencies will be less.

22. Disadvantages They aren’t always the easiest to install – but there is a clear process to follow that makes life much easier. The ride comfort isn’t as great because of the inter-leaf friction between each leaf. Over time, the springs tend to lose shape and can sag. When the sag is uneven, it can alter the cross weight of the vehicle which can affect the handling slightly. This can also change the axle-to-mount angle. Wind-up and vibration can be caused by acceleration and braking torque. The wind-up can also cause nose-diving and rear-end squat.

23. Why choose leaf springs? Large layers of metal are what make up the basic anatomy of a leaf spring, meaning they can deal with huge vertical loads. They offer a huge amount of support between the wheels, axles and the vehicles chassis, making them perfect for commercial vans, pickups, trailers and trucks, where the need to support greater weights is essential.

24. Applications

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