“Detailed Explanation of Reaming Tools and Processing Technology for CNC Milling Machines”
I. Introduction
In the processing of CNC milling machines, reaming is an important method for semi-finishing and finishing holes. The reasonable selection of reaming tools and the correct determination of cutting parameters are crucial for ensuring the machining accuracy and surface quality of holes. This article will introduce in detail the characteristics of reaming tools for CNC milling machines, cutting parameters, coolant selection, and processing technology requirements.
In the processing of CNC milling machines, reaming is an important method for semi-finishing and finishing holes. The reasonable selection of reaming tools and the correct determination of cutting parameters are crucial for ensuring the machining accuracy and surface quality of holes. This article will introduce in detail the characteristics of reaming tools for CNC milling machines, cutting parameters, coolant selection, and processing technology requirements.
II. Composition and Characteristics of Reaming Tools for CNC Milling Machines
Standard machine reamer
The standard machine reamer is composed of a working part, a neck, and a shank. There are three shank forms: straight shank, taper shank, and sleeve type, to meet the clamping requirements of different CNC milling machines.
The working part (cutting edge part) of the reamer is divided into a cutting part and a calibration part. The cutting part is conical and undertakes the main cutting work. The calibration part includes a cylinder and an inverted cone. The cylindrical part mainly plays the role of guiding the reamer, calibrating the machined hole, and polishing. The inverted cone mainly plays the role of reducing the friction between the reamer and the hole wall and preventing the hole diameter from expanding.
Single-edged reamer with indexable carbide inserts
The single-edged reamer with indexable carbide inserts has high cutting efficiency and durability. The insert can be replaced, reducing tool cost.
It is suitable for processing materials with high hardness, such as alloy steel, stainless steel, etc.
Floating reamer
The floating reamer can automatically adjust the center and compensate for the deviation between the machine tool spindle and the workpiece hole, improving the reaming accuracy.
It is especially suitable for processing occasions with high requirements for hole position accuracy.
Standard machine reamer
The standard machine reamer is composed of a working part, a neck, and a shank. There are three shank forms: straight shank, taper shank, and sleeve type, to meet the clamping requirements of different CNC milling machines.
The working part (cutting edge part) of the reamer is divided into a cutting part and a calibration part. The cutting part is conical and undertakes the main cutting work. The calibration part includes a cylinder and an inverted cone. The cylindrical part mainly plays the role of guiding the reamer, calibrating the machined hole, and polishing. The inverted cone mainly plays the role of reducing the friction between the reamer and the hole wall and preventing the hole diameter from expanding.
Single-edged reamer with indexable carbide inserts
The single-edged reamer with indexable carbide inserts has high cutting efficiency and durability. The insert can be replaced, reducing tool cost.
It is suitable for processing materials with high hardness, such as alloy steel, stainless steel, etc.
Floating reamer
The floating reamer can automatically adjust the center and compensate for the deviation between the machine tool spindle and the workpiece hole, improving the reaming accuracy.
It is especially suitable for processing occasions with high requirements for hole position accuracy.
III. Cutting Parameters for Reaming on CNC Milling Machines
Depth of cut
The depth of cut is taken as the reaming allowance. The rough reaming allowance is 0.15 – 0.35mm, and the fine reaming allowance is 0.05 – 0.15mm. Reasonable control of the depth of cut can ensure the machining quality of reaming and avoid tool damage or a decrease in hole surface quality due to excessive cutting force.
Cutting speed
When rough reaming steel parts, the cutting speed is generally 5 – 7m/min; when fine reaming, the cutting speed is 2 – 5m/min. For different materials, the cutting speed should be adjusted appropriately. For example, when processing cast iron parts, the cutting speed can be appropriately reduced.
Feed rate
The feed rate is generally 0.2 – 1.2mm. If the feed rate is too small, slippage and gnawing phenomena will occur, affecting the surface quality of the hole; if the feed rate is too large, the cutting force will increase, resulting in aggravated tool wear. In actual processing, the feed rate should be reasonably selected according to factors such as workpiece material, hole diameter, and machining accuracy requirements.
Depth of cut
The depth of cut is taken as the reaming allowance. The rough reaming allowance is 0.15 – 0.35mm, and the fine reaming allowance is 0.05 – 0.15mm. Reasonable control of the depth of cut can ensure the machining quality of reaming and avoid tool damage or a decrease in hole surface quality due to excessive cutting force.
Cutting speed
When rough reaming steel parts, the cutting speed is generally 5 – 7m/min; when fine reaming, the cutting speed is 2 – 5m/min. For different materials, the cutting speed should be adjusted appropriately. For example, when processing cast iron parts, the cutting speed can be appropriately reduced.
Feed rate
The feed rate is generally 0.2 – 1.2mm. If the feed rate is too small, slippage and gnawing phenomena will occur, affecting the surface quality of the hole; if the feed rate is too large, the cutting force will increase, resulting in aggravated tool wear. In actual processing, the feed rate should be reasonably selected according to factors such as workpiece material, hole diameter, and machining accuracy requirements.
IV. Coolant Selection
Reaming on steel
Emulsified liquid is suitable for reaming on steel. Emulsified liquid has good cooling, lubricating, and rust-proof properties, which can effectively reduce the cutting temperature, reduce tool wear, and improve the surface quality of holes.
Reaming on cast iron parts
Sometimes kerosene is used for reaming on cast iron parts. Kerosene has good lubricating properties and can reduce the friction between the reamer and the hole wall and prevent the hole diameter from expanding. However, the cooling effect of kerosene is relatively poor, and attention should be paid to controlling the cutting temperature during processing.
Reaming on steel
Emulsified liquid is suitable for reaming on steel. Emulsified liquid has good cooling, lubricating, and rust-proof properties, which can effectively reduce the cutting temperature, reduce tool wear, and improve the surface quality of holes.
Reaming on cast iron parts
Sometimes kerosene is used for reaming on cast iron parts. Kerosene has good lubricating properties and can reduce the friction between the reamer and the hole wall and prevent the hole diameter from expanding. However, the cooling effect of kerosene is relatively poor, and attention should be paid to controlling the cutting temperature during processing.
V. Processing Technology Requirements for Reaming on CNC Milling Machines
Hole position accuracy
Reaming generally cannot correct the position error of the hole. Therefore, before reaming, the position accuracy of the hole should be guaranteed by the previous process. During processing, the positioning of the workpiece should be accurate and reliable to avoid affecting the position accuracy of the hole due to workpiece movement.
Processing sequence
Generally, rough reaming is performed first, and then fine reaming. Rough reaming mainly removes most of the allowance and provides a good processing foundation for fine reaming. Fine reaming further improves the machining accuracy and surface quality of the hole.
Installation and adjustment of tools
When installing the reamer, ensure that the connection between the tool shank and the machine tool spindle is firm and reliable. The center height of the tool should be consistent with the center height of the workpiece to ensure the reaming accuracy.
For floating reamers, adjust the floating range according to processing requirements to ensure that the tool can automatically adjust the center.
Monitoring and control during processing
During processing, pay close attention to parameters such as cutting force, cutting temperature, and hole size changes. If abnormal conditions are found, adjust the cutting parameters or replace the tool in time.
Regularly check the wear condition of the reamer and replace the severely worn tool in time to ensure processing quality.
Hole position accuracy
Reaming generally cannot correct the position error of the hole. Therefore, before reaming, the position accuracy of the hole should be guaranteed by the previous process. During processing, the positioning of the workpiece should be accurate and reliable to avoid affecting the position accuracy of the hole due to workpiece movement.
Processing sequence
Generally, rough reaming is performed first, and then fine reaming. Rough reaming mainly removes most of the allowance and provides a good processing foundation for fine reaming. Fine reaming further improves the machining accuracy and surface quality of the hole.
Installation and adjustment of tools
When installing the reamer, ensure that the connection between the tool shank and the machine tool spindle is firm and reliable. The center height of the tool should be consistent with the center height of the workpiece to ensure the reaming accuracy.
For floating reamers, adjust the floating range according to processing requirements to ensure that the tool can automatically adjust the center.
Monitoring and control during processing
During processing, pay close attention to parameters such as cutting force, cutting temperature, and hole size changes. If abnormal conditions are found, adjust the cutting parameters or replace the tool in time.
Regularly check the wear condition of the reamer and replace the severely worn tool in time to ensure processing quality.
VI. Conclusion
Reaming on CNC milling machines is an important hole processing method. Reasonable selection of reaming tools, determination of cutting parameters and selection of coolant, and strict compliance with processing technology requirements are of great significance for ensuring the machining accuracy and surface quality of holes. In actual processing, according to factors such as workpiece material, hole size, and accuracy requirements, various factors should be comprehensively considered to select suitable reaming tools and processing technologies to improve processing efficiency and quality. At the same time, continuously accumulate processing experience and optimize processing parameters to provide strong support for the efficient processing of CNC milling machines.
Reaming on CNC milling machines is an important hole processing method. Reasonable selection of reaming tools, determination of cutting parameters and selection of coolant, and strict compliance with processing technology requirements are of great significance for ensuring the machining accuracy and surface quality of holes. In actual processing, according to factors such as workpiece material, hole size, and accuracy requirements, various factors should be comprehensively considered to select suitable reaming tools and processing technologies to improve processing efficiency and quality. At the same time, continuously accumulate processing experience and optimize processing parameters to provide strong support for the efficient processing of CNC milling machines.