钢琴击弦机构中的两项性能指标,是在我们的设计、制作、维修中不容忽视的两个问题。一是弦槌击弦至距弦1～3mm处时,顶杆与凸轮脱开,弦槌靠惯性力击弦,即我们通常所说的“断联”尺寸;二是弦槌击弦后返回,被托木托住时,弦槌距弦的距离,这里我们暂且称“返回”尺寸。试对其尺寸的变化所造成的影响分析如下: Two performance indicators in a piano strike mechanism are two issues that can not be ignored in our design, production and maintenance. First, the hammer hit the strings to 1 ~ 3mm away from the chord, ejector and cam off, the hammer by inertial force string, which we commonly referred to as “broken couplets” size; second hammer hit the string back , Was propped wood support, the distance from the string chord, here we temporarily call “back” size. The impact of changing the size of the test is as follows: