用表示式來畫

End_pitch=0.5-------------------------------------終止卷螺距

OD=1----------------------------------------------彈簧外直徑

Start_pitch=0.1075--------------------------------起始卷螺距

Turns=5-------------------------------------------彈簧圈數

Wire_dia=0.05-------------------------------------彈簧線徑

height=Turns*mean_pitch---------------------------彈簧高度

mean_pitch=(Start_pitch+End_pitch)/2--------------平均螺距

[mm]p0=Wire_dia

[mm]p1=0

rad=OD/2------------------------------------------彈簧外半徑

t=1-----------------------------------------------規律曲線

x=t*height

x1=0

x2=mean_pitch

x3=height-mean_pitch

x4=height

xt=cos(360*Turns*t)*rad---------------------------X規律

yt=sin(360*Turns*t)*rad---------------------------Y規律

z1=0

z2=Start_pitch

z3=height-End_pitch

z4=height

zt=zt1+zt2+zt3+zt4--------------------------------Z規律

zt1=(((x-x2)*(x-x3)*(x-x4)/((x1-x2)*(x1-x3)*(x1-x4))))*z1

zt2=(((x-x1)*(x-x3)*(x-x4)/((x2-x1)*(x2-x3)*(x2-x4))))*z2

zt3=(((x-x1)*(x-x2)*(x-x4)/((x3-x1)*(x3-x2)*(x3-x4))))*z3

zt4=(((x-x1)*(x-x2)*(x-x3)/((x4-x1)*(x4-x2)*(x4-x3))))*z4

變螺距彈簧在已知起始螺距和終止螺距、圈數條件下利用拉格朗日插值法確定Z值變化規律