To process key mold components, such as cores, inserts, and copper cores, mold factories primarily use CNC machining centers. The quality of cores and inserts directly determines the quality of molded parts, while the quality of copper core machining directly affects EDM processing. Ensuring CNC machining quality depends on pre-processing preparation. This role requires extensive machining experience, mold knowledge, and effective communication, especially with the production team and colleagues.
CNC Machining Process
Here’s the CNC machining process:
Read the drawings and program sheets.
Transfer the corresponding program to the machine tool.
Check the program header and cutting parameters.
Determine machining dimensions and allowances on the workpiece.
Properly clamp the workpiece.
Accurately align the workpiece.
Accurately establish workpiece coordinates.
Properly select tools and cutting parameters.
Properly clamp the tools.
Use a safe test cutting method.
Observe the machining process.
Adjust cutting parameters.
Give timely feedback to relevant personnel about any problems during machining.
Inspect the workpiece’s quality after machining.
Precautions Before Processing
For new molds, ensure the processing drawings meet all requirements and the data is clear. A supervisor must sign the drawings, and you must fill in all columns.
Check that the quality department has given the workpiece a qualified mark.
After receiving the program sheet, check whether the workpiece’s reference position is consistent with the drawing’s reference position.
Carefully read each requirement on the program sheet and confirm whether the program is consistent with the drawing’s requirements. If you find any problems, you must solve them with the programmer and the production team.
Based on the material and size of the workpiece, judge whether the tool the programmer selected for roughing or finishing is reasonable. If you find the tool application is unreasonable, you should notify the programmer immediately to make changes. This will improve processing efficiency and accuracy.
Precautions for Clamping Workpieces
When you clamp the workpiece, pay attention to the bracket’s position and the nut bolt’s extension length on the pressure plate. Also, the screw should not hit the bottom when you lock the corner.
You typically process copper for the locking plate. Before you load it, compare the number of cuts to the number on the program sheet to ensure consistency. At the same time, check to see if you have tightened the screws for closing the plate.
When you collect multiple copper materials on one board, check whether the direction is correct and if each copper material will interfere during processing.
Clamp the workpiece according to the shape on the drawing on the program sheet and the workpiece size data. Note that the workpiece size data is written as XxYxZ. If there’s a loose parts drawing, check whether the drawing on the program sheet is consistent with it. Pay attention to the direction of out-feed and the placement of the X and Y axes.
When you clamp the workpiece, you must check whether its size meets the size requirements on the program sheet. If there is a loose parts drawing, you must check whether the size on the program sheet is the same as the size on that drawing.
Precautions for Clamping Tools
Securely clamp the tool. It should not be too short in the tool holder.
Before each tool insertion, check that the tool meets the requirements. You should determine the tool’s insertion length based on the machining depth on the program sheet. Generally, it should be about 2mm longer than the machining depth. Also, consider whether the tool holder will collide with the workpiece.
If you are machining at very deep depths, consult with the programmer. Consider using a two-step tool insertion method. First, insert the tool to half to two-thirds of its length. Then, when you machine at a deeper depth, insert a longer tool. This will improve machining efficiency.
When you use an extended tool insert, it is particularly important to understand the insertion depth and the required tool length.
Precautions for Calibrating and Aligning Workpieces
When you drag the workpiece, pay attention to its verticality. Drag one side flat, then drag the vertical side.
When you center the workpiece, you must center it twice for verification.
After centering, check the center position according to the external dimensions on the program sheet and the dimensions on the loose parts drawing.
You must use the centering method to center all workpieces. You must also use the centering method to find the zero position on the workpiece’s edge and then move to the edge. You must ensure the margins on both sides are consistent. If a situation requires you to count only one side, you must first confirm with the production team. After you have completed the one-side counting, remember to compensate for the centering rod’s radius.
The zero position you input for the workpiece’s center must be the same as the three-axis center in the workstation computer drawing.
Workplace Organization
Follow 5S requirements.
Keep tools, gauges, fixtures, and workpieces neatly organized.
Clean the machine tools.
Clean the workplace floor.
Return finished tools, unused tools, and gauges to storage.
Send finished workpieces to quality inspection or the appropriate department.