Preparation work that must be done before programming the CNC machining center

For our CNC machining center, programming is essential before any production operation. Programming directly affects the efficient production and safe processing of our workpieces. So what should we do before programming? What are the precautions? Then Bian Xiao will give you a detailed introduction

After determining the processing technology of the CNC machining center, understand before programming:

1. Workpiece clamping method;

2. The size of the workpiece blank-to determine the processing range or whether multiple clamping is required;

3. The material of the workpiece-to choose what kind of tool to use for processing;

4. What tools are in stock? Avoid modifying the program because there is no such tool in the processing process. If you must use this tool, you can prepare it in advance.

What is the principle of setting the safety height in programming?

Safety height setting principle: generally higher than the highest surface of the island. Or set the programming zero point on the highest plane to minimize the risk of tool collision.

Why does the tool trajectory of the CNC machining center need post-processing after compilation?

Since different CNC machining center machine tools can recognize different address codes and CNC program formats, it is necessary to select the correct post-processing format for the machine tool used to ensure that the compiled program can run.

How to choose the cutting route?

The feed route refers to the trajectory and direction of the tool relative to the workpiece during CNC machining. The reasonable selection of the machining route is very important because it is closely related to the machining accuracy and surface quality of the parts. When determining the feed route:, the following points should be considered:

(1) The CNC machining center ensures the machining accuracy of the parts.

(2) It is convenient for numerical calculation and reduces programming workload.

(3) Seek the shortest machining route, reduce time and improve machining efficiency.

(4) Minimize the number of programs.

(5) Ensure the roughness requirements of the contour surface of the workpiece after machining, and arrange the final contour continuous machining in the last process.

(6) The advance and retreat (cut-in and cut-out) route of the CNC machining center tool should also be carefully considered to minimize the tool marks caused by stopping at the contour (elastic deformation caused by sudden changes in cutting force) and avoid cutting the workpiece vertically on the contour surface.

What aspects should be paid attention to when determining the workpiece clamping method?

When determining the positioning reference and clamping scheme, the following three points should be noted:

(1) Strive to unify the reference of design, process and programming calculation.

(2) Minimize the number of clamping times and try to process all the surfaces to be processed after one positioning.

(3) Avoid using manual adjustment schemes.

(4) The clamp should be opened smoothly, and its positioning and clamping mechanism should not affect the feed during the processing (such as collision). In such a situation, Chenghai CNC experts recommend using a vise or adding a bottom plate to pull the screws for clamping.

What principles should be followed in arranging the processing sequence?

The arrangement of the processing sequence should be based on the structure of the parts, the condition of the blank, and the need for positioning and clamping, emphasizing that the rigidity of the workpiece should not be destroyed. Generally speaking, it should be sorted according to the following principles:

(1) The processing of the previous process cannot affect the positioning and clamping of the next process, and the processing procedures of general machine tools should also be considered comprehensively.

(2) Perform the inner cavity addition process first, and then the shape processing process.

(3) It is best to connect with the same positioning clamping method or the same tool processing technology to reduce the number of repeated positioning, tool changes and moving platens.

(4) For multiple processes performed in the same installation, the process that causes less damage to the workpiece rigidity should be arranged first.

The division of CNC machining processes can generally be carried out according to the following methods:

(1) The tool centralized sorting method is to divide the processes according to the tools used, and all parts that can be completed with the same tool are completed. The second and third tools are used to complete the other parts that they can complete. This can reduce the number of tool changes, shorten idle time, and reduce unnecessary positioning errors.

(2) The machined parts can be divided into several parts such as internal shape, external shape, curved surface or plane according to their structural characteristics. Generally, planes and positioning surfaces are machined first, and then holes. Simple geometric shapes are machined first, and then complex geometric shapes; parts with lower precision are machined first, and then parts with higher precision requirements.

(3) For parts that are easy to deform during machining, shape correction is required because they may be deformed after rough machining. Therefore, generally speaking, rough machining and fine machining should be carried out separately. In summary, when dividing the process, we must flexibly grasp the structure and processability of the parts, the function of the machine tool, the content of the CNC machining of the parts, the number of installations, and the production organization of the unit. In addition, it is recommended to adopt the principle of centralized process or decentralized process, which should be determined according to the actual situation, but must be reasonable.