Bidirectional Spline Cutting Tool for Resin Layer Removal

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Solution Overview

Problem

Conventional cutting tools cannot effectively process male spline shafts with portions larger in diameter than the splines due to the inability to pull out the tool after forward movement, resulting in incomplete resin layer removal and scratching issues.

Innovation Solution

A cutting tool with blade portions formed on both ends, allowing for forward and rearward movement to accurately process splines by using first and second blade portions to remove the resin layer in sequential steps, ensuring complete processing without scratching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the cutting tool has blade portions only on one end, then the structure is simple, but the tool cannot be pulled out from shafts with portions larger in diameter than the splines

Engineering Contradiction:
Improvecutting tool structureVSAvoidtool extraction
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The cutting tool is segmented into multiple functional zones along its axial direction. Blade portions are provided at both the first end and second end of the tool body, allowing different segments to perform cutting functions during forward and rearward movements respectively. This segmentation enables the tool to be extracted from shafts with varying diameter portions without getting stuck.

Inventive Principle:
Principle #1Segmentation

2Productivity

If the cutting tool moves forward only, then the processing direction is simple, but the resin layer springs back and is not cut in a predetermined manner

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidresin layer cutting precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The cutting process employs periodic bidirectional movement rather than continuous unidirectional motion. The tool alternates between forward movement (where the first blade portions cut the resin layer) and rearward movement (where the second blade portions cut the sprung-back resin layer). This periodic action ensures complete and precise removal of the resin layer without springback issues.

Inventive Principle:
Principle #19Periodic action

3Device complexity

If the blade portions are directed toward one direction, then the tool design is simple, but the tool cannot process shafts with varying diameter portions effectively

Engineering Contradiction:
Improveblade portion configurationVSAvoidshaft type adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The cutting tool is designed with multi-functionality to handle various shaft configurations. By providing blade portions at both ends directed toward respective ends, the tool can universally process different types of shafts including those with portions larger in diameter than the splines. The first blade portions handle forward movement cutting while the second blade portions handle rearward movement cutting, making the tool adaptable to diverse processing requirements.

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

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate processing of male splines on shafts with varying diameters, preventing resin layer scratching and ensuring complete removal during both forward and rearward movements.

Implementation Method 1

The blade portions are disposed on one end side in the axial direction, and directed toward the one end side... the resin layer which is formed on the male spline shaft 21 in a thicker manner is scratched off by the cutting tool 25

Methodology Applied
Scientific EffectMechanical cutting: Abrasion

Data Source

PatentEP3040147B1Cutting tool and spline processing method
Publication Date: 2021.06.16 JTEKT CORP
  • EP3040147B1 patent drawingFigure 1
  • EP3040147B1 patent drawingFigure 2
  • EP3040147B1 patent drawingFigure 3

AI summary

A cylindrical cutting tool for processing splines formed on an outer circumference of a shaft member to extend in an axial direction includes blade portions which are formed in a spline shape on an inner circumference. The blade portions include: a first blade portion which is formed in a terminal end portion in a first direction along the axial direction and which is directed substantially toward the first direction; and a second blade portion which is formed in a terminal end portion in a second direction along the axial direction and opposite to the first direction and which is directed substantially toward the second direction.