Stepped End Mill with Dividing Grooves for Wire Stripping

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Solution Overview

Problem

Existing end mills are limited in their application to only milling layered composite materials and struggle with delamination and fiber protrusions when processing fiber composite plastics, and they are not suitable for stripping wires effectively.

Innovation Solution

An end mill design with a shaft and cutting head featuring helically extending cutting webs divided by counter-rotating helical dividing grooves, allowing for a transition section with a smaller diameter that enables machining and stripping of wires with rectangular cross-sections, and incorporating negative rake angles and angled open spaces for improved surface quality and reduced friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the end mill is designed with a uniform outer diameter and standard cutting edges for milling layered composite materials, then delamination and fiber protrusions are prevented through opposing axial cutting forces, but the tool cannot effectively strip wires with rectangular cross-sections

Engineering Contradiction:
Improveapplication rangeVSAvoidsurface quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The cutting head is divided into multiple cutting steps with different outer diameters (first cutting step with diameter D1, second cutting step with diameter D2 < D1), allowing each step to perform different functions. The dividing grooves segment the cutting edges into multiple cutting edge segments, creating both main cutting edges for material removal and auxiliary cutting edges for surface finishing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the tool are given different properties: the first cutting step has a larger diameter for effective wire stripping, while the second cutting step has a smaller diameter for precise surface finishing. The cutting edges have different orientations and functions (main vs auxiliary) to address different requirements of the wire stripping process

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the end mill uses a single cutting step design optimized for milling, then machining precision for layered composite materials is maintained, but the tool cannot adapt to wire stripping applications requiring different geometric contours

Engineering Contradiction:
Improvefunctional capabilityVSAvoidtool structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The end mill is designed to perform multiple functions: wire stripping, surface finishing, and potentially milling operations. The multiple cutting steps with different diameters and the divided cutting edges enable the tool to adapt to different operational requirements within a single tool structure

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The tool transitions from a two-dimensional cutting edge to a three-dimensional multi-step structure with varying diameters along the axial direction. This dimensional expansion allows the tool to engage with workpieces at different radii and perform diverse operations

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If the end mill employs dividing grooves to create multiple cutting edge segments, then opposing cutting forces are generated to prevent delamination, but the tool structure becomes more complex and manufacturing more difficult

Engineering Contradiction:
Improvedelamination preventionVSAvoidtool fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The cutting edges are divided into multiple segments by dividing grooves, creating distinct main cutting edges and auxiliary cutting edges. This segmentation enables the generation of opposing cutting forces that prevent delamination while maintaining controllable manufacturing through systematic groove placement

Inventive Principle:
Principle #1Segmentation

4Productivity

If the end mill uses a larger outer diameter for effective wire stripping, then material removal efficiency is improved, but surface quality on the machined workpiece deteriorates due to increased cutting forces

Engineering Contradiction:
Improvestripping efficiencyVSAvoidsurface finish quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The cutting process is segmented into two distinct steps: the first cutting step with larger diameter D1 performs aggressive material removal for efficient stripping, while the second cutting step with smaller diameter D2 performs precise surface finishing. This segmentation allows both high productivity and high precision to be achieved in sequence

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a single-diameter design to a multi-diameter design along the axial dimension. This allows the tool to apply different cutting intensities at different axial positions, achieving both efficient material removal and high-quality surface finish

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4454795A1End mill
Publication Date: 2024.10.30 GUEHRING KG
  • EP4454795A1 patent drawingFigure 1~2
  • EP4454795A1 patent drawingFigure 3
  • EP4454795A1 patent drawing

AI summary

The present invention relates to an end mill (1; 100) with a shank (10) and a cutting head (20) having a number of helically extending cutting edges (50) spaced apart from one another by clamping grooves (30), wherein the cutting edges (50) are divided into cutting edge segments (60) at least over a portion of their length by a number of counter-helically extending dividing grooves (40). The cutting head (20) is divided into a shank-side cutting step (22) and an end-side cutting step (24) adjoining the shank-side cutting step (22) via a transition section (23), the end-side cutting step having a smaller cutting diameter than the shank-side cutting step (22).