气弹簧

弹簧的弹性系数k与弹簧的直径，弹簧的线径，弹簧的材料，弹簧的有效圈数有关。具体关系是：
与弹簧圈的直径成反比，与弹簧的线径的4次方成正比，与弹簧的材料的弹性模量成正比，与弹簧的有效圈数成反比。
c=F/λ＝Gd4/8D23＝Gd/8C3n
上式中：
c：弹簧的刚度(即所说的弹性系数，中学物理叫倔强系数k)；
F：弹簧所受的载荷；
λ：弹簧在受载荷F时所产生的变形量；
G：弹簧材料的切变模量(钢为8×104MPa，青铜为4×104MPa)；
d：弹簧丝直径；
D2：弹簧直径；
n：弹簧有效圈数；
C：弹簧的旋绕比(又称为弹簧指数)。
由上式可知。当其它条件相同时，C值愈小的弹簧，刚度愈大，亦即弹簧愈硬；反之则愈软。还应注意到，C值愈小，弹簧内、外侧的应力差愈悬殊，卷制愈难，材料利用率也愈低，并且在工作时将引起较大的扭应力。所以在设计弹簧时，一般规定C≥4，且当弹簧丝直径d越小时，C值越宜取大值。

中译英：
The elasticity of the spring coefficient K and the diameter of the springs, spring wire, spring material, the effective coil number of the spring. Specific relationship is:
And the spring coil diameter inversely, and the spring wire diameter4 times proportional to the spring, and the elastic modulus of the material is directly proportional to the effective coil number, and the spring is inversely proportional.
c=F/λ＝Gd4/8D23＝Gd/8C3n
Type of:
C:the stiffness of the spring(i.e., the elastic coefficient, high school physics called stiffness coefficient K);
F:spring loads;
Lambda:spring in the load of F generated by deformation of;
G:spring material 's shear modulus(steel is 8×104MPa to 4×104MPa, bronze);
D:spring wire diameter;
D2:diameter of spring;
N:the effective coil number of springs;
C:spring winding ratio(also known as the spring index).
Based on the formula one. When the other conditions were the same, C value is a small spring, stiffness is bigger, namely spring more hard; otherwise the soft. It should also be noted that, C value is small, spring, lateral stress difference is disparate, winding more difficult, the material utilization rate is lower, and the work will lead to larger torsional stress. So in the design of a spring, general provisions of C≥4, and when the spring wire diameter d more hours, C value is to employ large value.
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