It has been less than five years since cnc precision machining

The ultra-fine processing equipment of mechanical processing manufacturers mainly includes: CNC machining centers, fine grinding machines and CNC lathes, etc.; CNC machining center machine tools have high precision, and have common advantages in high precision, complex, and small batch parts processing; fine grinding machines are fine processing equipment One is mainly finishing, which is mainly for the processing of hardened parts; CNC lathes are also active processing equipment, and the processing of general shafts, rods, and round parts has advantages for special precision requirements or small batch parts.

cnc precision machining

A. CNC processing technology and working principle

1. Distinguish between working procedure and working step; determine the tool setting point and tool changing point;

2. Determination of processing routes; selection of processing methods and determination of processing schemes.

3. Reasonable selection of machine tools, select different types of workpiece accuracy;

4. Installation of parts and selection of fixtures;

5. Selection of cutting tools and determination of cutting amount;

6. Technical analysis of CNC machining parts, reasonable processing technology.

B. Correct operation method of CNC precision processing plant

Mainly digitize a few pieces of information and process information on the machining parts map of Changzhou machinery parts, that is, the relative motion path of the tool and the workpiece, the change of the spindle speed and feed speed during the CNC machining process, the coolant switch, the workpiece and the tool The manipulations and operations such as changing are all compiled into a processing program according to the prescribed code and format, and then the program is input into the CNC system.

The numerical control system performs the corresponding calculation and processing according to the requirements of the program, and then announces the control instructions, so that the coordinate axes, spindles, and auxiliary actions are in harmony with each other, to realize the relative movement of the tool and the workpiece, and to actively complete the processing of the parts.

cnc precision machining

C. The precision selection of CNC machine tools considers these factors

The precision of CNC machine tools is different from the precision of processing technology. They show two different concepts of CNC machine tools. One is the precision of the machine tool and the other is the precision of the process. These two reasons seem to be unrelated, but they are actually related. )

It is wrong to regard the azimuth accuracy on the manufacturer's sample or product qualification certificate as the machining accuracy of the machine tool. The azimuth accuracy indicated on the sample or certificate is the accuracy of the machine tool, and the machining accuracy is the sum of errors that occur in various factors in the entire process system, including the errors that the machine tool itself promises. When selecting the model, please refer to the evaluation method of process ability kp as the basis for selecting the accuracy.

CNC precision has a decisive influence on processing quality. It should be noted that machining accuracy and machine tool accuracy are two different concepts. The stiffness of the machine tool directly affects the yield and processing accuracy. The processing speed of the machining center is much higher than that of the general machine tool, and the motor power is also higher than the general machine tool of the same standard, so the rigidity of its structural design is also much higher than the general machine tool. When ordering, according to the process requirements, the maximum torque, power, axial force and feed force allowed, the calculation is based on the values provided by the manufacturer.

cnc precision machining

D. How to maintain the high strength of the parts for fine parts processing

The criteria for improving the strength of parts are: selecting high-strength materials, heat-treating the materials to increase strength and reduce internal stress, manipulating the processing technology to reduce or eliminate micro-defects, etc.; strive to reduce the load on the parts; increase the risk profile of the parts Scale, design the shape of the section reasonably to increase the moment of inertia of the section; properly touch the structure of the parts to reduce the degree of stress concentration, etc.

CNC fine parts processing can carry out multi-coordinate linkage and can process parts with complex shapes; high processing accuracy and stable processing quality; mass production, product quality is easy to control; when processing parts are changed, generally only need to change the CNC program, can Save production preparation time; high precision and rigidity of the machine tool, you can choose a favorable amount of processing, high yield (generally 3 to 5 times the general machine tool); high degree of machine tool initiative, can reduce labor intensity; for the operator The professional quality requirements are lower, and the skills of the maintenance personnel are higher.

The first prerequisite for CNC fine parts processing is the accuracy of the process reference. The reference on the mechanical drawings are indicated by capital letters A, B, C, D, etc. with a specific circled reference symbol. When the reference symbol is aligned with the surface When the extension line of the surface or the scale limit of the surface indicates that the surface is the reference. When the reference symbol is aligned with the scale line, it indicates that the center line of the entity marked with the scale is used as the reference.