Cutting Insert Dual Rake Face Chip Control

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Solution Overview

Problem

Existing cutting inserts generate thick chips, leading to increased heat and wear on the cutting edges, resulting in reduced tool life due to the small rake angle along cutting edges and the likelihood of chips colliding with the rake face, causing further wear.

Innovation Solution

A cutting insert with a rake face featuring two distinct rake angles, where the first rake face has a smaller angle for effective cutting and the second rake face has a larger angle to reduce chip thickness and prevent chip contact, combined with a chip breaker design that promotes chip curling and deformation, thereby reducing heat generation and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a small rake angle is used along cutting edges, then effective cutting is achieved, but thick chips are generated leading to increased heat and wear

Engineering Contradiction:
Improvecutting efficiencyVSAvoidchip temperature
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The rake face is divided into two distinct regions: a first rake face with a smaller rake angle for effective cutting, and a second rake face with a larger rake angle for chip thinning. This segmentation allows each region to perform its specific function optimally, resolving the contradiction between cutting efficiency and chip temperature control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different rake angles are applied to different locations on the rake face. The first rake face (near the cutting edge) has a smaller angle for effective cutting, while the second rake face (further from the cutting edge) has a larger angle for chip thinning. This local differentiation addresses the contradiction by providing location-specific functionality.

Inventive Principle:
Principle #3Local quality

2Productivity

If a small rake angle is used along cutting edges, then effective cutting is achieved, but the cutting insert wears away faster reducing tool life

Engineering Contradiction:
Improvecutting efficiencyVSAvoidtool life
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The rake face is segmented into two functional zones with different rake angles. The first rake face maintains smaller angles for effective cutting, while the second rake face provides larger angles to thin chips before they contact the breaker wall, reducing wear and extending tool life.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rake face exhibits local quality variations with different rake angles in different regions. This local differentiation allows the cutting insert to maintain both cutting efficiency and reduced wear through location-specific rake angle optimization.

Inventive Principle:
Principle #3Local quality

3Productivity

If chips are thick, then they collide against the breaker wall surface, but this causes increased wear on the rake face

Engineering Contradiction:
Improvechip breaking functionVSAvoidrake face material loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The second rake face with a larger rake angle performs preliminary chip thinning before the chips reach the breaker wall surface. This preliminary action reduces chip thickness, preventing excessive collision and wear on the rake face while maintaining effective chip breaking.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2481504B1Cutting insert and cutting tool
Publication Date: 2019.07.24 TUNGALOY CORP
  • EP2481504B1 patent drawingFigure 1
  • EP2481504B1 patent drawingFigure 2
  • EP2481504B1 patent drawingFigure 3

AI summary

The present invention relates to a cutting insert with a cutting edge. The cutting insert includes a rake face (24) extending along a cutting edge (22a, 22b) and a rising wall surface (32a) extending so as to form a recess (34) along the cutting edge (22a, 22b) together with the rake face (24). The rake face (24) is formed to have a positive rake angle, and includes a first rake face (24a) and a second rake face (24b) arranged in order in a direction in which a distance from the cutting edge (22a, 22b) increases. The second rake face (24b) is larger than the first rake face (24a) in rake angle.