| 摘要 |
PURPOSE:To obtain the non-linear load characteristic of a coil spring even when a pitch and diameter of the coil spring, consisting of a spring strand in constant diameter, are formed to constant, by using an alloy of Ni-Ti system for material of the spring strand forming the coil part. CONSTITUTION:For instance, in a closely wound tension coil spring having a coil part formed by a spring strand, an alloy of Ni-Ti system is used as material of the spring strand to obtain a non-linear load characteristic when the coil part formed by the spring strand in a constant diameter is not applied with initial tension further its pitch and diameter are even constant respectively. Composition of the above described alloy is arranged to, for instance, 51-52a t% Ni and 48-49a t% Ti. In this way, there can be obtained a non-linear sag S- load W characteristic. Accordingly, a desired non-linear load characteristic can be obtained by setting diameters of the spring strand and the coil part and effective windings to a suitable constant value respectively. |
