はかり用の一体型平行ばね機構の変位特性(第1報)

同一寸法の板ばねの場合

抄録

There is a singular point in the movement, whose rectilinear displacement remains constant independent of the loading position of a mass. The point is located at the geometrical center of two springs. It is, however, clarified in this paper that strictly analyzing displacement of springs by using the theory of beam subject to combined loads, the point deviates from the center. The results reported are; (1) The deviation of the point is expressed as, x_p/l₀=-(3/175)(δy₀/t₀)² (s/l₀), where l₀, t₀; half length and thickness of leaf spring, s; loading position of the mass, measured from the center, and δy₀; displacement of the point at s=0, equivalent to the true value of the mass. (2) Letting δy, be displacement of an arbitrary point x, the ratio, (δy-δy₀)/δy₀ means the error rate of the mass to be weighed. The ratio is written as, (δy-δy₀)/δy₀_??_(t₀/L₀)²(s/l₀)(x/l₀), where L₀; height between two springs. Since t₀/L₀ is, in general, very small, as small values of s/l₀ and x/l₀ as possible contribute to the design of a balance with high accuracy.