“Detailed Explanation of Common Machining Methods for CNC Machine Tools – Boring Machining”
I. Introduction
In the field of machining with CNC machine tools, boring machining is an extremely important technological means. It can expand the inner diameter of holes or other circular contours with cutting tools and has wide applications from semi-rough machining to finish machining. CNC machine tool manufacturers will hereby introduce in detail the principles, methods, characteristics, and applications of boring machining.
In the field of machining with CNC machine tools, boring machining is an extremely important technological means. It can expand the inner diameter of holes or other circular contours with cutting tools and has wide applications from semi-rough machining to finish machining. CNC machine tool manufacturers will hereby introduce in detail the principles, methods, characteristics, and applications of boring machining.
II. Definition and Principle of Boring Machining
Boring is a cutting process in which a rotating single-edged boring cutter is used to expand a prefabricated hole on a workpiece to a certain size to achieve the required precision and surface roughness. The cutting tool used is usually a single-edged boring cutter, also known as a boring bar. Boring is generally carried out on boring machines, machining centers, and combination machine tools. It is mainly used to process cylindrical holes, threaded holes, grooves inside holes, and end faces on workpieces such as boxes, brackets, and machine bases. When special accessories are used, inner and outer spherical surfaces, tapered holes, and other special-shaped holes can also be processed.
Boring is a cutting process in which a rotating single-edged boring cutter is used to expand a prefabricated hole on a workpiece to a certain size to achieve the required precision and surface roughness. The cutting tool used is usually a single-edged boring cutter, also known as a boring bar. Boring is generally carried out on boring machines, machining centers, and combination machine tools. It is mainly used to process cylindrical holes, threaded holes, grooves inside holes, and end faces on workpieces such as boxes, brackets, and machine bases. When special accessories are used, inner and outer spherical surfaces, tapered holes, and other special-shaped holes can also be processed.
III. Classification of Boring Machining
- Rough boring
Rough boring is the first process of boring machining. The main purpose is to remove most of the allowance and lay a foundation for subsequent semi-finish boring and finish boring. During rough boring, the cutting parameters are relatively large, but the processing precision requirements are low. Generally, high-speed steel cutter heads are used, and the cutting speed is 20-50 meters/minute. - Semi-finish boring
Semi-finish boring is carried out after rough boring to further improve the hole precision and surface quality. At this time, the cutting parameters are moderate, and the processing precision requirements are higher than those of rough boring. When using a high-speed steel cutter head, the cutting speed can be appropriately increased. - Finish boring
Finish boring is the last process of boring machining and requires high precision and surface roughness. During finish boring, the cutting parameters are small to ensure processing quality. When using a carbide cutter head, the cutting speed can reach more than 150 meters/minute. For precision boring with very high precision and surface roughness requirements, a jig boring machine is generally used, and cutting tools made of ultra-hard materials such as carbide, diamond, and cubic boron nitride are used. A very small feed rate (0.02-0.08 mm/rev) and cutting depth (0.05-0.1 mm) are selected, and the cutting speed is higher than that of ordinary boring.
IV. Tools for Boring Machining
- Single-edged boring cutter
The single-edged boring cutter is the most commonly used tool in boring machining. It has a simple structure and strong versatility. Different materials and geometric shapes can be selected according to different processing requirements. - Eccentric boring cutter
The eccentric boring cutter is suitable for processing some holes with special shapes, such as eccentric holes. It controls the processing size by adjusting the eccentricity. - Rotating blade
The rotating blade can improve the service life and processing efficiency of the tool. It can automatically rotate during the processing process to make the cutting edge wear evenly. - Special back boring cutter
The back boring cutter is used for processing back bored holes. On CNC machine tools, we often use non-standard tools and use CNC machining programs for back boring.
V. Process Characteristics of Boring Machining
- Wide processing range
Boring machining can process holes of various shapes, including cylindrical holes, threaded holes, grooves inside holes, and end faces. At the same time, special-shaped holes such as inner and outer spherical surfaces and tapered holes can also be processed. - High processing precision
By reasonably selecting cutting tools, cutting parameters, and processing technologies, high processing precision can be achieved. Generally speaking, the boring precision of steel materials can reach IT9-7, and the surface roughness is Ra2.5-0.16 microns. For precision boring, the processing precision can reach IT7-6, and the surface roughness is Ra0.63-0.08 microns. - Strong adaptability
Boring machining can be carried out on different types of machine tools, such as boring machines, machining centers, and combination machine tools. At the same time, different cutting tools and processing technologies can be selected according to different processing requirements. - Large overhang distance and easy to generate vibration
Due to the large overhang distance of the boring bar, vibration is easy to occur. Therefore, appropriate cutting parameters need to be selected during the processing process to reduce the impact of vibration on processing quality.
VI. Application Fields of Boring Machining
- Machinery manufacturing industry
In the machinery manufacturing industry, boring machining is widely used in the processing of workpieces such as boxes, brackets, and machine bases. These workpieces usually need to be processed with high-precision cylindrical holes, threaded holes, and grooves inside holes. - Automotive manufacturing industry
In the automotive manufacturing industry, key components such as engine blocks and transmission cases need to be processed with high precision by boring. The processing quality of these components directly affects the performance and reliability of automobiles. - Aerospace industry
The aerospace industry has extremely high requirements for the processing precision and quality of components. Boring machining is mainly used to process key components such as engine blades and turbine discs in the aerospace field. - Mold manufacturing industry
In the mold manufacturing industry, the cavities and cores of molds usually need to be processed with high precision by boring. The processing quality of these components directly affects the service life of molds and the quality of products.
VII. Precautions for Boring Machining
- Tool selection
Select appropriate tool materials and geometric shapes according to different processing requirements. For high-precision processing, tools made of ultra-hard materials should be selected. - Selection of cutting parameters
Reasonably select cutting parameters to avoid excessive cutting force and vibration. During rough boring, the cutting parameters can be appropriately increased to improve processing efficiency; during finish boring, the cutting parameters should be reduced to ensure processing quality. - Workpiece installation
Ensure that the workpiece is firmly installed to avoid displacement during processing. For high-precision processing, special fixtures and positioning devices should be used. - Machine tool precision
Select a machine tool with high precision and good stability for boring machining. Regularly maintain and maintain the machine tool to ensure its precision and performance. - Processing process monitoring
During the processing process, closely monitor the processing status and timely adjust the cutting parameters and tool wear. For high-precision processing, online detection technology should be used to monitor the processing size and surface quality in real time.
VIII. Conclusion
As one of the common machining methods for CNC machine tools, boring machining has characteristics such as a wide processing range, high precision, and strong adaptability. It has wide applications in industries such as machinery manufacturing, automotive manufacturing, aerospace, and mold manufacturing. When performing boring machining, it is necessary to reasonably select cutting tools, cutting parameters, and processing technologies, pay attention to workpiece installation and machine tool precision, and strengthen processing process monitoring to ensure processing quality and efficiency. With the continuous development of CNC technology, the precision and efficiency of boring machining will continue to improve, making greater contributions to the development of the manufacturing industry.
As one of the common machining methods for CNC machine tools, boring machining has characteristics such as a wide processing range, high precision, and strong adaptability. It has wide applications in industries such as machinery manufacturing, automotive manufacturing, aerospace, and mold manufacturing. When performing boring machining, it is necessary to reasonably select cutting tools, cutting parameters, and processing technologies, pay attention to workpiece installation and machine tool precision, and strengthen processing process monitoring to ensure processing quality and efficiency. With the continuous development of CNC technology, the precision and efficiency of boring machining will continue to improve, making greater contributions to the development of the manufacturing industry.