Inspection square box

The inspection square box is mainly used for checking the parallelism and verticality of components and supporting workpieces during marking.It is generally a cube with the same side length,and can be made into various specifications and equal height square boxes and rectangular cylinders according to user requirements.A square box is a cubic cavity made of cast iron with six working faces,one of which has a V-shaped groove.The environmental conditions for square box calibration are normal temperature and constant humidity.

Requirements for inspection of square boxes:Each working surface of the square box must be free of rust,scratches,cracks,dents,and other defects that affect the metrological performance.Non working surfaces should be sandblasted and painted with chamfered edges.There should be a label on the inner wall of the square box,indicating the specifications,dimensions,level,factory number,and manufacturer name.

The inspection method for square boxes is similar to that of ordinary cast iron square boxes.For square boxes with a side length of 300mm or less,1mm measuring blocks are placed at both ends of the inspected surface of the square box during the inspection.A knife edge ruler is placed on the working surface of the measuring block,and then a measuring block is used to test the plug at each inspected point.The difference between the size of the equivalent block group when just inserted and the size of the measuring blocks at both ends is the deviation between the inspected point and the two ends.This calibration should also be carried out on several cross-sections of the square box working surface in the longitudinal,transverse,and diagonal directions.When the error direction in the measured straight lines at each position is consistent,the maximum value is taken.When the error direction is inconsistent,the sum of its large positive and large negative differences is taken as the flatness of the tested surface plane.

Testing the accuracy of the square box:In addition to verifying the flatness of the scraped square box,the contact spot should also be verified using the coloring method.The number of spots in any square with a side length of 25mm is:no less than 25 points for level 1 and level 2;Level 3 with no less than 20 points.