根据光滑极限量规国家标准(GB1957—81),通规尺寸公差带的中心到工件最大实体尺寸之间的距离Z(简称为内缩值)如图1所示,Z按精度等级和基本尺寸分段,应符合国标规定的数值。设置内缩值Z的原因,是考虑到通规每次检测部通过合格件,因而将产生较多的磨损,故Z值起着保证量规预定使用期限的重要作用,为量规设计的标准参数之 According to the national standard for smooth limit gauge (GB1957-81), the distance Z between the center of the gauge tolerance band and the largest physical dimension of the workpiece (abbreviated as shrinkage value) is shown in Fig. 1, Z is divided by accuracy class and basic dimension Paragraph, should be consistent with the national standard values. The reason for setting the retraction value Z is that it takes more consideration of each pass of the pass through the qualified parts and thus produces more wear and tear. Therefore, the value of Z plays an important role in guaranteeing the intended service life of the gauge and is the standard parameter for the gauge design