1 Scribing tool and scribing method
Method of marking with a stylus
Commonly used marking tools Common scribing tools include needles, gauges, paddles, scribing discs, square boxes, flat plates, and like punches.2 Choice of dash reference
When marking, the rest of the dimension lines should be drawn based on a certain line or a certain surface on the workpiece. Such a line (or surface) is called a dash reference. The dash reference should be consistent with the design datum. The datum of the blank is generally selected with its axis or mounting plane as the reference. The support base shown in FIG. 1 should be based on the design reference B surface and the A line (symmetry line) as a rule, and the full size limit can be drawn according to the dimensions on the drawing.
Figure 1 benchmarking
3 steps
Lines are divided into flat and three-dimensional lines. Plane scribing marks a surface of a workpiece in a manner similar to mechanical drawing. Three-dimensional scribes are scribed on several surfaces of the workpiece, such as in the length, width, height direction, or other oblique direction. The three-dimensional scribing of the workpiece is usually performed on a scribing platform. When scribing, the workpieces are often supported by jacks, and some workpieces can also be supported by square boxes, V-shaped blocks, and the like.
1) Preparation before scribing
Before blanking, blanks should be cleaned (clear the surface of the blanks to remove burrs). The scribe surface should be coated with a thin and uniform coating. The blank surface should be white or chalk. (Gentiana violet plus shellac and alcohol) or green paint (malachite green plus shellac and alcohol). Holes in the workpiece, but also use lead or block block holes in order to determine the center of the hole.
2) three-dimensional marking operation
FIG. 2 shows a three-dimensional scribing method of a bearing housing, which is a blank line. The lines and specific steps are shown in Figures 2b to f.
Figure 2 The three-dimensional scribe of the bearing seat