The metal cutting tool cuts off the surplus metal on the workpiece through the CNC machine tool, so that the workpiece is formed. CNC machine tools, east-west system and tool management are the basis of CNC machine tool power and quality assurance. So CNC machine tools in the processing of common problems and solutions and tools have a direct relationship.
The following are some problems frequently encountered in the process of NC machining, and there are many solutions. Therefore, if you do not have enough experience to directly find the breakthrough point of the problem, you can also use the “elimination method” for comparison.
These defects and detection methods are processed and tested for reference when we encounter problems in work.
- The scale of workpiece is accurate and the surface finish is poor
Cause of the problem
The tool tip is damaged and not sharp; the machine tool resonates and is not placed smoothly; the machine tool crawls; the processing technology is not good.
Solution:
If the tool is not sharp after being worn or damaged, it is necessary to grind the tool from the beginning or select a better tool to set the tool from the beginning; if the machine tool resonates or is not placed stably, adjust the level, lay the foundation and fix it stably; the reason for the creeping of the machine is that the guide rail of the carriage is severely worn, and the ball screw ball is worn or loosened, so the machine tool should be maintained.
Clean the iron wire after work and add lubricating oil in time to reduce friction; select the coolant suitable for workpiece processing, and select a higher spindle speed as far as possible when it can meet the processing requirements of other processes.
CNC machining
- Large and small taper of workpiece
Cause of the problem
The placement level of the machine tool is not adjusted well, one high and one low, resulting in unstable placement; when turning the long shaft, the contribution material is relatively hard, and the cutting tool is relatively deep, resulting in a tool yielding phenomenon; the tailstock thimble is not concentric with the spindle.
Solution:
Use level to adjust the levelness of the machine tool, lay a solid foundation, fix the machine tool and improve its toughness; select a reasonable process and appropriate cutting feed rate to avoid the force on the tool; adjust the tailstock.
- The driver phase light is normal, but the size of the workpiece processed is large or small
Cause of the problem
The carriage of the machine tool runs at high speed for a long time, which leads to the wear of screw rod and bearing;
The carriage can return to the machining starting point accurately every time, but the scale of the workpiece still changes. This phenomenon is generally caused by the spindle. The high-speed rolling of the spindle makes the bearing wear seriously, resulting in the change of machining scale.
Solution:
Use the dial indicator to lean against the bottom of the tool rest, and at the same time, modify a fixed cycle program through the system, check the repeated positioning accuracy of the carriage, adjust the screw clearance, and replace the bearing; use the dial indicator to check the repeated positioning accuracy of the tool rest, adjust the machinery or replace the tool rest; use the dial indicator to check whether the workpiece is accurately returned to the starting point of the program. If it can, overhaul the spindle and replace the bearing.
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