Programming instructions

ADT-CNC4620 Programming Manual
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A: Geometric accuracy of the machine tool refers to the geometric shape accuracy of the basic parts
of the machine tool, geometric accuracy of relative position, and geometric accuracy of the relative
motion. The work precision of the machine tool is the precision of the machine tool in motion
state and under the effect of the cutting force. The precision of the machine tool in work state is
reflected on the precision of the processed parts.
32. What are the conditions of ribbon cutting?
A: When process plastic metal materials, the cutting speed is high, cutting thickness is low, cutting
angle is large, the slide amount of the chips is low, haven’t destroyed the materials, and thus form
ribbon chips.
33. What is the important meaning of process analysis?
A: Appropriate process analysis has important meaning to ensure processing quality, improve
productivity, reduce production cost, reduce labor strength and make reasonable process
regulations.
34. What are design reference and process reference (including assembly reference, positioning
reference, measurement reference and procedure reference)?
A: (1) Design reference is the reference on the part drawing to determine the positions of other
points, lines and surfaces.
(2) Process reference is the reference of the parts used in processing and assembly. According
to the purpose, it is divided into assembly reference, measurement reference, positioning
reference and procedure reference.
1) Assembly reference is used to confirm the position of the part in component and product
during assembly.
2) The measurement reference is used to measure the size and position of processed surface.
3) The positioning reference is used to make the workpiece occupy the proper position in
machine tool or clamp during processing.
4) Procedure reference is used to confirm the size, shape and position precision of the
processed surface on the procedure drawing.
35. What is the reason of positioning error? How to calculate?
A: When a batch of workpieces are processed in clamp, the reasons for errors in processing size
might be:
1) The maximum displacement of same batch of workpieces along the direction of processing
size caused by the size and geometric shape error of the positioning reference and the
clearance between the positioning reference and positioning components is called positioning
reference displacement error, which is expressed in NY.
2) The displacement of the size of same batch workpieces relative to procedure reference
caused by noncoincidence between procedure reference and positioning reference is called
reference noncoincidence error, which is expressed in ÑB.
The sum of above errors is positioning error, resulting in the formula ÑD=ÑY +ÑB. The
positioning reference displacement error and reference noncoincidence error that cause positioning
error also include many elements respectively in calculation. For example, in addition to the
clearance in NY, the geometric shape and position error of clamp positioning component
(verticality, coincidence degree) also have influence on reference displacement.