Please tell me about the deflection of the compression coil springs. In general, it is stated that the amount of deflection should be in the range of 20% to 80% of the total amount of deflection, but if a spring is designed and used outside the above range, what kind of problems might occur?
Spring Newbie, thank you for your contribution!
The reason why it is appropriate that the amount of deflection of the compression coil spring is between 20% and 80% of the total deflection is that when the compression coil spring is compressed, the contact part of the seat coil changes and therefore it is difficult to obtain linear characteristics immediately after, and near when the spring reaches its solid height. In order to obtain linear characteristics from immediately after compression to when the spring reaches its solid height, we can design an open end without a seat coil, or eliminate the contact between the coils due to compression by creating a closed end and set the pitch angle. Applying these methods, we can design a structure to expand the range of linear characteristics. (In calculation, you can consider that the effective number of coils changes slightly.)
This is an additional question for the above answer.
When using springs, the initial load is set individually using a mechanism that adjusts the amount of deflection for each spring, and no special provision is required when the amount of deflection during use changes (that is, load characteristics). If you don’t need the linearity of the load characteristic, is it okay to use it at 5% to 95%, for example, without being bound by the idea of 20% to 80%? What are the possible disadvantages of this usage?
If the linearity of the load characteristics is not required, it may be used in the range exceeding 20% to 80%. As a caveat, the load characteristics will rise as the spring reaches its solid height, there is a possibility that a higher stress than the calculated stress will be applied. Therefore, it is necessary to consider the possibility that the spring will reach its solid height when designing. If you can tell us the detailed specifications here , we will propose a design. Thank you!
