Circular Cutting Insert Clamping for Precise Edge Indexing

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Solution Overview

Problem

Existing cutting tools with indexable cutting inserts face challenges in optimizing the indexing of circular cutting edges, leading to non-optimum usage and increased production costs, especially with ultra-hard inserts like cubic boron nitride, due to the risk of improper indexing.

Innovation Solution

A cutting tool design featuring a toolholder with a pocket, a clamp, and a fastening element, where a resilient element connects the clamp to the toolholder body, allowing for adjustable clamping forces to facilitate rotational indexing of cutting edges, providing tactile feedback for optimal engagement of indexing elements and preventing the cutting unit from falling out during indexation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a cutting insert with a circular cutting edge is used, then the cutting edge can be indexed to create multiple cutting edge portions, but the risk of non-optimum indexing increases which affects cutting quality or increases production cost

Engineering Contradiction:
Improvenumber of cutting edge portionsVSAvoidindexing precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent introduces indexing indication elements as intermediary components that mediate between the cutting unit and the operator. These elements provide tactile feedback during rotation to indicate when a cutting edge portion is properly positioned, thereby improving indexing precision without compromising the ability to create multiple cutting edge portions

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The indexing indication elements provide tactile feedback to the operator during the indexing process. When a cutting edge portion is properly positioned, the operator feels a distinct tactile signal, enabling precise indexing. This feedback mechanism directly addresses the precision problem while maintaining productivity

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If indexing indication elements are added to guide proper indexing, then indexing precision improves, but the device complexity increases

Engineering Contradiction:
Improveindexing precisionVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Rather than making the entire cutting tool complex, the patent applies indexing indication elements only at specific local positions where indexing occurs. The elements are positioned to provide tactile feedback only when needed during rotation, keeping the rest of the tool structure simple and maintaining ease of manufacture

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The indexing indication elements change their physical state or position in response to rotation, providing tactile feedback only at specific angular positions. This dynamic parameter change allows precise indexing guidance without requiring complex mechanical structures throughout the entire tool

Inventive Principle:
Principle #35Parameter changes

3Strength

If a clamp is used to secure the cutting unit, then the cutting unit is held firmly during cutting, but the cutting unit cannot be rotated for indexing

Engineering Contradiction:
Improveclamping forceVSAvoidindexing operation
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The clamp is designed with dynamic characteristics that allow it to transition between a locked state during cutting (providing strong clamping force) and a released state during indexing (allowing free rotation). The resilient element enables this dynamic behavior by storing and releasing mechanical energy as needed

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If the fastening element is loosened to allow indexing, then the cutting unit can be rotated, but the cutting unit may fall out of the pocket

Engineering Contradiction:
Improveindexing operationVSAvoidcutting unit retention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The resilient element is pre-configured to provide a biasing force that prevents the cutting unit from falling out during indexing operations. This beforehand cushioning mechanism ensures that even when the fastening element is loosened, the cutting unit remains securely retained through the elastic restoring force

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The solution reduces the risk of non-optimum indexing, ensures maximum usage of cutting edges, and maintains stability and contact during the indexing process, thereby optimizing the cutting operation and extending the life of the cutting insert.

Implementation Method 1

the cutting tool further comprises a resilient element connecting the clamp with the toolholder body, wherein the resilient element is configured to generate a biasing force acting on the clamp to press the clamping surface towards the cutting unit top surface

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4353386A1A cutting tool comprising a cutting edge and a method for indexing such a cutting edge
Publication Date: 2024.04.17 SECO TOOLS AB
  • EP4353386A1 patent drawingFigure 1~2
  • EP4353386A1 patent drawingFigure 3~4
  • EP4353386A1 patent drawingFigure 5~6

AI summary

The invention is related to a cutting tool (100) comprising a toolholder body (110), a cutting unit (120), a clamp (160) having a clamping surface (162), and a fastening element (180), wherein the cutting unit (120) is secured in the toolholder body (110) by the fastening element (180) which is adjustable to generate a clamping force acting on the clamp (160) to press the clamping surface (162) toward the cutting unit (120). The cutting unit (120) comprises a circular cutting edge (124) comprising a plurality of cutting edge portions (126). The cutting tool (100) is configured to be shifted between an operation state and an indexing state by adjusting the fastening element (180) to provide a corresponding clamping force, wherein the cutting tool (100) further comprises a resilient element (190) connecting the clamp (160) with the toolholder body (110), wherein the resilient element (190) is configured to generate a biasing force acting on the clamp (160) to press the clamping surface (162) towards the cutting unit top surface (130), wherein - in the operation state, the clamping force is larger than the biasing force, - in the indexing state, the clamping force is smaller than the biasing force. The invention also relates to a method (200) for indexing the cutting edge (124) in the cutting tool (100).