Cutting Insert Grooves with Varying Clearance Angles

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Solution Overview

Problem

Cutting inserts with a cutting edge mounted on tools experience high cutting forces and low cutting performance due to uncut portions of the work material interfering with grooves, leading to vibration and strength deterioration.

Innovation Solution

The cutting insert features grooves extending from the side surface to the upper surface, with varying clearance angles, where the clearance angle nearest to the low-positioned portion is greater than that nearest to the high-positioned portion, reducing interference and vibration, and maintaining the strength of the cutting edge by retaining the height of the high-positioned corner cutting edges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If grooves are added to the cutting insert to reduce cutting force, then cutting performance is improved, but uncut portions interfere with the grooves causing vibration and strength deterioration

Engineering Contradiction:
Improvecutting performanceVSAvoidvibration and strength deterioration
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by varying the clearance angles of different grooves based on their specific positions. The groove nearest to the low-positioned corner portion has a larger clearance angle, while the groove nearest to the high-positioned corner portion has a smaller clearance angle. This localized differentiation allows each groove to optimally handle the interference from uncut portions in its specific region, reducing vibration and preventing strength deterioration while maintaining improved cutting performance.

Inventive Principle:
Principle #3Local quality

2Productivity

If the cutting edge is made thinner to improve cutting performance, then cutting force is reduced, but strength of the cutting edge deteriorates

Engineering Contradiction:
Improvecutting performanceVSAvoidstrength of the cutting edge
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent applies parameter changes by optimizing the clearance angles of the grooves. By setting the clearance angle of the groove nearest to the low-positioned corner portion to be larger than that of the groove nearest to the high-positioned corner portion, the design allows the cutting edge to be thinner for improved cutting performance while the varying clearance angles compensate for the reduced strength, preventing interference-induced vibration and maintaining overall structural integrity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2070620B1Cutting insert, cutting tool using the same, and cutting method
Publication Date: 2019.06.05 KYOCERA CORP
  • EP2070620B1 patent drawingFigure 1~2
  • EP2070620B1 patent drawingFigure 3
  • EP2070620B1 patent drawingFigure 4(a)~4(c)

AI summary

A cutting edge is formed at a ridge between an upper surface and a side surface. In the side surface, a plurality of grooves are formed so as to extend from the side surface to the upper surface to divide the cutting edge, and the clearance angles within these grooves are formed so as to increase from one end of the cutting edge toward the other end of the cutting edge. This achieves a cutting insert having small cutting force and excellent cutting performance. Among the plurality of grooves, the groove nearest to the one end of the cutting edge has preferably a width increasing from the upper surface of the cutting insert toward the lower surface.