In recent years, with the rapid development of the socialist market economy, the industrial demand for the quality of machine-processed products is also higher and higher, especially some high-precision parts, the machining accuracy and quality of the product has a very high demand.
The CNC lathe is an important tool for high-precision parts processing. Many parts require the use of CNC lathes. However, with the continuous improvement of modern processing, the efficiency of CNC lathe processing struggles to meet the demand for high-precision parts.
To address this, effective control of the influencing factors in CNC lathe high-precision parts processing is necessary.
At this stage, there is still a lot of room for improvement in the quality of CNC lathe parts processing, so it is necessary to adjust the CNC lathe in order to improve the quality of parts with irregular shape but with high processing accuracy.
CNC parts
The importance of CNC lathe high precision parts processing quality control
Before the use of CNC lathes, factories have been using ordinary lathes, which are mainly used for manual work.
In the machining process, workers must effectively control errors with the human eye, three-grip chucks, turntables, and other components. This helps improve the processing quality of the parts.
However, the efficiency and accuracy of this process are not high. It also cannot be scaled for large production. As a result, it is difficult to meet the current rapid development of social and economic needs.
With the development of science and technology, the increased demand for parts is growing, and CNC machines are gradually replacing general machine tools for parts manufacturing.
In CNC turning, the operator only needs to input the programmed NC code into the machine’s control system, and then the lathe will cut according to the specified path.
In modern machine tool equipment, the increasing use of various types of CNC machine tools underscores the importance of enhancing machine tool production quality and elevating manufacturing standards.
CNC Technology’s Role in Global Competitiveness and National Development Strategies
In today’s global economic integration, the market competitiveness of machine tools is getting stronger and stronger, and a country’s level of machine tool manufacturing can also reflect the side of the country’s production strength, which helps to achieve the international competitive environment of mechanical competitiveness .
Currently, many developed countries in the West treat CNC machining equipment and CNC technology as a key part of their national development strategy.
This approach aims to enhance their technological strength. These countries constantly learn from the experience of other developed nations and adopt advanced technology. This contributes significantly to improving the national manufacturing level.
CNC turner high-precision parts processing influencing factors
Some studies have shown that there is a large error between the machining accuracy of CNC machines and the actual needs of production. In the manufacturing process of high-precision workpieces, due to programming, equipment, procedures and many other aspects, the processing quality of the machine tool also has a greater impact.
Usually, we will choose the ratio of the manufacturing error of the machine tool to the process error, if the casting parts require higher precision, then the error of the CNC machine will be greater.
Therefore, to improve the accuracy of the casting process, so that it meets the production requirements, it is necessary to strictly control the various factors affecting the accuracy of the machine tool, at the same time with the processing of the actual combination of targeted optimisation and improvement, which will help to improve the accuracy of CNC lathe machining. (Table 1)
Table 1 CNC lathe processing error
1. Servo system driving factors
CNC machine tool servo control system actuators have an important impact on the manufacture of high-precision workpieces, generally through the servo drive to drive the machine tool fixture device, so as to achieve the manufacture of high-precision workpieces.
The process is: through the CNC car on the ball screw monitoring, servo and drive motor help to ensure that the manufacture of high-precision CNC machine tool shape.
However, in actual production, due to the error of the ball screw drive, it will have a great impact on the machining accuracy of the machine tool.
In practice, the screw must reverse the mechanism, which is highly susceptible to idling, followed by a reverse backlash deviation.
The CNC machine tool will torsion when subjected to external action, resulting in elastic backlash in certain machining areas, which severely restricts the machine tool’s machining accuracy.
2. Turning tool control factors
In the process of CNC machine tool mould making, in order to meet the shape requirements of the mould, it is necessary to cut a suitable tool.
When cutting the tool, the control surface of the tool and the size of the spindle are very prone to error, which leads to the cutting deformation of the part.
This necessitates selecting optimal cutting parameters as much as possible during the CNC machine’s programming process, while simultaneously addressing issues like cutting errors that arise due to the challenge of precisely executing the tool’s movement path.
High-precision parts quality control strategy based on CNC turners
1. Control servo system drive error
When designing the CNC machine tool, it is necessary to tightly control the servo drive to keep it within the optimized interval.
Effective control of the servo drive manufacturing deviation, first of all, from the characteristics of the operation of the drive equipment to optimise the link, the drive equipment for efficient regulation, so as to ensure that the machine tool in the process of driving can achieve efficient management.
On this basis, we further optimize the load and air pressure of the servo drive system to enable efficient loading of parts by the servo drive, thereby enhancing the control accuracy of the machined parts.
In order to improve the accuracy of the CNC machine, after installing the servo device, but also to do a good job of optimal control of the machine’s machining state.
2. Machine cutting parameters control
(1) Correct selection of tools.
In the CNC machine before cutting, we must first consider the material of the tool, in the selection of tools, in addition to better toughness, hardness and wear resistance, but also have the ability to resist high pressure and high temperature.
Currently, cemented carbide and high-speed steel are the most commonly used cutting tools. Cemented carbide exhibits better high-temperature performance than high-speed steel (up to 1000°C) and possesses excellent high-temperature characteristics (hardness and wear resistance).
(2) Tool selection.
By making reasonable selections of tool parameters, such as the deviation of the tool tip from the spindle center, the tool tip radius, and the main inclination angle, one can achieve precise control over the radial and axial directions of the workpiece.
In the selection, comprehensive consideration of the workpiece material, machining requirements and models and other factors, in order to determine the optimal machining process.
(3) Workpiece positioning method.
When positioning the workpiece, it is advisable to minimize the amount of cutting. Utilizing a CNC machine in conjunction with clamping enhances the efficiency of workpiece clamping. This approach not only shortens the machining cycle but also applies to various parts of the fastening, resulting in a more favorable economic effect.
CNC parts
3. Strictly control the geometrical accuracy of turning tool operation
In the CNC lathe, the geometric accuracy of the turning tool directly affects the processing of high-precision parts. Based on this, CNC lathe designers must consider actual production conditions.
During the manufacturing process, one should continuously implement optimization and improvement. This helps further improve the geometric accuracy of the turning tool. As a result, the tool will have better extrusion performance and manufacturing precision.
Additionally, one can effectively regulate and control the use of the tool.
During the tool manufacturing process, manufacturers typically design the overall structure with a tilt to fully utilize the functionality of CNC machine tools. This design approach enhances the bearing capacity and bending performance of CNC machine tools.
4. Improvement of error compensation
CNC lathe in the processing of high-precision parts during the use of error compensation technology can significantly improve the actual processing efficiency of CNC lathe, the technology is an effective complement to the current coordinate axis, the use of software and hardware combination of methods for high-precision parts processing.
The 0.5 level closed-loop control has been studied, as the reverse deviation will lead to a decrease in the positioning accuracy of the workpiece. This deviation should be eliminated by reverse error compensation.
Similar to the parts machining accuracy limitation, the error compensation technology can make reasonable use of the current CNC lathe without changing the original design, which greatly saves the production cost. In addition to this, manufacturers also utilize the error compensation method for ball screws with needle feed.
Since in the production process of CNC machine tools, the accuracy of pin feeding is likely to cause errors in the accuracy of CNC machine tools, therefore, CNC machine tool controllers should choose the method of gap compensation;
To compensate for the offset of the ballscrew, thus improving the service life and stability of the ballscrew of CNC machine tools.
5. Application of optimal processing technology
To enhance the machining accuracy of high-precision parts on a CNC lathe, one must take two crucial actions. Firstly, one must efficiently manipulate the CNC machine.
Second, efficient regulation and control of the cutting method and manufacturing process are essential. These measures will improve both the efficiency and accuracy of high-precision workpiece manufacturing, ultimately enhancing the overall quality of the workpieces.
First, the machining process of the CNC control device should be closely controlled. The goal is to complete the high-precision parts in one attempt. If it cannot be done in one attempt, try to minimize the number of replacements.
Additionally, separate the fine machine tools from the coarse ones. This will help enhance the quality of high-precision zero-point machining.
In addition, it is also necessary to preferentially select the CNC lathe process path, in the selection of travelling trajectory, shorten the machine tool’s work cycle, increase the cutting efficiency of the tool, remove unnecessary work steps; thus achieving the purpose of improving the economic efficiency of the CNC machine tool process.
Before processing high-precision workpieces with a CNC machine tool, one must debug it, reprogram it, and then restart it so that the CNC machine can operate autonomously until the end of the manufacturing process.
The operator has to perform process programme entry, tooling, programming, monitoring of production conditions, assembly and disassembly.
To reduce work intensity and achieve intelligent machine operation, in addition to the processing phase of the CNC lathe, one should strive to accurately determine surface roughness and accuracy. The process of calculating these values should be further streamlined to lessen the workload on the CNC machine.
6. Error prevention strategy
The development of error prevention strategies, in the design and production of CNC lathes during the continuous improvement of lathe fixture parts accuracy, from the overall level to reduce the process accuracy deviation.
However, for parts manufacturers, based on the original CNC lathe, it is often difficult to improve the accuracy of parts processing, which requires changes to the original CNC lathe. Therefore, the error prevention strategy has a high cost of use [8].
Optimisation solutions
1. Enhance the operator’s ability to strengthen the accuracy of tool setting and status
During CNC lathe processing, tool control is an important part of processing high-precision parts, and the operation is more difficult.
Tool calibration and clamping accuracy will have a direct impact on the subsequent processing steps of high-precision parts, and will also control the machining accuracy of the workpiece, and improve the manufacturing quality of high-precision parts of great significance.
At present, the detailed division of knife to knife has two kinds of manual knife and automatic knife knife, of which the manual knife is more common.
In the cutting process, the manual knife is very easy to cause abnormal knife problems, resulting in abnormal tool wear, therefore, to improve the process technology of the operators, improve the training of the operators to the knife and loading skills is an important way to improve the processing quality of the workpiece.
2. Use simulation software to increase the rationality and accuracy of CNC programme
In today’s rapid development of science and technology, a variety of simulation simulation software is endless, CNC simulation simulation system to help designers accurately complete the programming code verification;
In the actual production process, you can visualise the process of high-precision parts, in the simulation of parts cutting, you can check it, so as to optimise the source program code, to achieve the quality of high-precision parts processing.
Conclusion
In conclusion, CNC lathe is the basis and important carrier of machining production, with a high degree of automation, high operating efficiency and other advantages, optimization and improvement of CNC lathe technology, help to improve the quality of CNC lathe high-precision parts processing.
