Stepped Rake Face Cutting Insert for Scratch-Free Machining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cutting inserts often leave scratch marks on processed workpieces due to their design, which does not effectively manage the interaction between the cutting edge and the workpiece surface.
Innovation Solution
The cutting insert features a rake face with a level difference portion that crosses or does not cross the main cutting edge, along with a specific angle and distance configuration, to reduce the occurrence of scratch marks by controlling the swarf outlet direction and velocity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the rake face has a substantially constant inclination angle in the extending direction of the main cutting edge, then the cutting insert structure is simple, but scratch marks remain on the processed surface
Solution Approach 1:
The rake face is segmented into multiple portions (first, second, third rake face portions) with different inclination angles. The second rake face portion has a smaller inclination angle than the first rake face portion, creating a level difference portion that divides the previously uniform rake face into functionally distinct zones for chip control and surface finish optimization.
Solution Approach 2:
Different regions of the rake face are given different inclination angles tailored to their specific functions. The first rake face portion (larger angle) handles general chip flow, while the second rake face portion (smaller angle) specifically controls swarf outlet direction to prevent scratch marks, and the third rake face portion handles the corner cutting edge area.
2Productivity
If the swarf outlet direction is not controlled, then the cutting process is simple, but scratch marks are generated on the workpiece surface
Solution Approach 1:
The inclination angle parameter of the rake face is changed in the second rake face portion to create a level difference. This parameter change redirects the swarf outlet direction away from the processed surface, preventing scratch marks while maintaining cutting efficiency through the optimized angle configuration.
3Object-affected harmful factors
If the rake face inclination angle varies in the extending direction of the main cutting edge, then scratch marks are suppressed, but the rake face structure becomes complex
Solution Approach 1:
The rake face is divided into three distinct portions, each with specific inclination angle characteristics. This segmentation allows the second rake face portion to have a different angle for scratch mark suppression while the first and third portions maintain appropriate angles for their respective functions, managing complexity through systematic division.
Solution Approach 2:
The multi-portion rake face structure serves multiple functions simultaneously: the first portion manages general chip flow, the second portion controls swarf outlet direction to prevent scratch marks, and the third portion handles corner cutting edge chip evacuation. This multi-functionality justifies the increased structural complexity by delivering multiple performance benefits in a single integrated design.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A cutting insert according to the present disclosure includes a first surface, a second surface, a side surface, and a cutting edge. The first surface has a rake face continuous to the cutting edge. The cutting edge has a corner cutting edge, a flat cutting edge, and a main cutting edge. The rake face has a first rake face portion, a second rake face portion, and a third rake face portion, the first rake face portion being continuous to the flat cutting edge, the second rake face portion being continuous to the main cutting edge, the third rake face portion being continuous to the corner cutting edge and being located between the first rake face portion and the second rake face portion. The rake face is provided with a level difference portion. The level difference portion is constituted of a rising surface, a first region, and a second region. The rising surface rises from the first region and is continuous to the second region. The main cutting edge includes a first main cutting edge portion, a second main cutting edge portion, and a third main cutting edge portion continuous to the corner cutting edge. The first main cutting edge portion is continuous to the third main cutting edge portion at a first boundary portion, rises from the first boundary portion, and is continuous to the second main cutting edge portion at a second boundary portion.