Coils springs are characterised by considerable formability and high ability for the accumulation of energy. Owing to that, together with shock absorbers, they serve to basic purposes:
- isolate the interior of a vehicle from vibration caused by road surface unevenness,
- keep the wheels in contact with the road surface, which facilitates acceleration, braking or turning a vehicle.
The shape of end coils is of a crucial importance to a coil spring operation. It is recommended that a contact plain, if possible, create a full ring in order to eliminate eccentric load. The design of end coils should also ensure correct spring centring on resistance coils.
Cylindrical coil springs
The most commonly used springs in vehicle suspension design are cylindrical springs. They ensure constant spring rate at the constant ascending angle of the bar and allow a high degree of automation of production.
Pigtail coil springs
Pigtail end coils (decreased end coil diameter) allows a more secure fitting of the spring on bearing elements. That type of ending at one end of the spring do not cause much difficulty in production, however, the ending of two resistance coils in the same way requires additional operation with use of special tooling.
Miniblok springs
Mini block coil springs are characterised by variable diameter of particular coils. This system of design has such a result that during the application of load to the spring its coils successively set on resistance plain. Owing to that, it is possible to attain a particularly low spring under load, which does not limit trunk volume.
Moreover the miniblock spring is of progressive characteristic, that is spring rate increases with the increase of load. This is advantageous for human physiology from the point of view of vehicle vibration.
The production of that type of springs is more highly advanced technically regarding both bar material preparation and coiling process as well as heat treatment process.
