CNC Lathe Turning with Adjustable Rake Angle for Tool Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In metal cutting, particularly with hard materials, cutting tools experience wear on the rake and flank faces, leading to reduced tool life and eventual tool breakage, necessitating frequent replacements, which is inefficient and costly.
Innovation Solution
A turning method for CNC lathes that involves rearranging the cutting element's nominal rake angle to maintain effective clearance and rake angles, compensating for wear, thereby extending tool life and ensuring high-quality machined surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a CBN or ceramic cutting element is used to machine hard materials, then wear resistance is improved, but tool life is eventually limited by wear on the rake face and flank face
Solution Approach 1:
The patent applies dynamics by making the rake angle adjustable during the machining process. The cutting element's orientation is changed from a fixed static configuration to a dynamic one where the rake angle can be modified based on wear progression. This allows the tool to adapt its geometry to compensate for wear, thereby extending tool life while maintaining effective wear resistance of the CBN or ceramic material.
Solution Approach 2:
The patent implements parameter changes by varying the rake angle of the cutting element during machining. As the cutting element wears, the rake angle is adjusted (changed) to compensate for the wear effects. This parameter modification allows the tool to maintain optimal cutting conditions throughout its service life, extending the duration of action while the high wear resistance of CBN or ceramic continues to protect against material loss.
2Duration of action of moving object
If a secondary layer is applied on the rake face to increase resistance to crater formation, then tool life is somewhat prolonged, but wear eventually deteriorates the cutting properties
Solution Approach 1:
The patent overcomes the limitation of static secondary layers by introducing dynamic adjustment of the rake angle. While the secondary layer provides initial protection against crater formation, the ability to change the rake angle during machining allows continuous compensation for wear effects. This dynamic adaptation maintains reliable cutting properties throughout the tool's extended life, rather than allowing gradual deterioration.
Solution Approach 2:
The patent applies preliminary action by proactively adjusting the rake angle before significant deterioration of cutting properties occurs. By monitoring wear and adjusting the rake angle in advance, the system prevents the cutting element from reaching a state where cutting properties are compromised, thereby maintaining reliability throughout the extended tool life.
3Productivity
If the cutting element is used as long as possible for efficiency and economic reasons, then productivity is improved, but wear leads to tool breakage and reduced machining quality
Solution Approach 1:
The patent resolves this contradiction by making the rake angle dynamic rather than fixed. As the cutting element wears during extended use, the rake angle is adjusted to compensate for wear effects. This allows the tool to maintain consistent machining quality and surface finish throughout its extended service life, enabling continuous high-productivity operation without sacrificing precision or risking catastrophic failure.
Solution Approach 2:
The patent implements feedback by continuously monitoring the wear state of the cutting element and using this information to adjust the rake angle. This closed-loop control ensures that even as the tool is used extensively for high productivity, the system detects wear progression and makes compensatory adjustments to maintain manufacturing precision and prevent tool breakage.
Data Source
Figure 1~3
Figure 4~5
Figure 6A~6C
AI summary
The invention relates to a turning method for a CNC lathe involving at least two machining steps wherein a cutting element (1, 11) is re-arranged between the machining steps such that a nominal rake angle (γn) is changed. Thereby, the effective tool life may be increased and a high quality of the machined surfaces, and a stable cutting process, may be achieved even with a worn tool. The invention also relates to a system and to a computer program for performing the method.