Analyze the key points of the layer-by-layer turning process in CNC turning

The key points of the process in CNC layer-by-layer turning mainly include the following aspects:

First, the basic principle of layer turning

Layer-by-layer turning is a process that divides deep processing grooves (such as thread grooves) into several layers at a certain depth. Through layer-by-layer processing, complex processing is transformed into multiple simple processing steps, thereby reducing cutting difficulty, improving processing accuracy and surface quality. During the layer-by-layer turning process, the cutting depth of each layer can be selected according to specific circumstances, usually being the same or decreasing layer by layer.

Second, analysis of key process points

Cutting depth control

During rough turning, the cutting depth of each layer can be appropriately increased to improve the processing efficiency. For example, when roughly turning trapezoidal threads, the cutting depth of each layer can be selected from 0.3mm to 0.5mm.

When performing finish turning, the cutting depth of each layer should be reduced to ensure processing accuracy and surface quality. For example, when precisely turning trapezoidal threads, the cutting depth of each layer can be selected from 0.05mm to 0.15mm.

Selection of knife movement mode:

Layer-by-layer turning usually adopts the combined application of the direct feed method and the left-right cutting method. On each layer, the cutting is carried out directly to a certain depth first, and then the cutting is carried out alternately left and right until the processing of that layer is completed.

When cutting left and right, the cutting depth should be kept constant. The turning tool should only make longitudinal feed to the left or right to avoid simultaneous cutting on three sides of the tool and reduce the force on the tool.

Cutting parameter optimization

According to the workpiece material, tool material and machine tool performance, the cutting parameters such as cutting speed, feed rate and depth of cut should be reasonably selected.

The cutting speed should not be too high to avoid overheating of the tool and accelerated wear. The feed rate should be moderate to ensure smooth cutting and smooth chip removal. The depth of cut should be adjusted according to the requirements of layer-by-layer turning.

Tool selection and wear monitoring

When rough turning, tools with high strength and good durability should be selected. When performing finish turning, tools with high precision and good durability should be selected.

During the processing, the wear of the cutting tools should be closely monitored, and severely worn tools should be replaced in a timely manner to ensure the processing quality and efficiency.

Cutting fluid usage:

During the layer-by-layer turning process, cutting fluid should be used for cooling and lubrication to lower the cutting temperature, reduce tool wear and improve the quality of the machined surface.

The selection of cutting fluid should be determined based on the material of the workpiece and processing requirements to ensure that the cutting fluid has good cooling, lubricating and anti-rust performance.

Programming and processing sequence:

The programming of layer-by-layer turning should take into account factors such as the cutting depth, tool path mode and cutting parameters of each layer to ensure the continuity and stability of the processing procedure.

The processing sequence should be reasonably arranged. Principles such as rough processing first and then fine processing, near processing first and then far processing, and internal and external intersection should be followed to improve processing efficiency and ensure processing quality.