Hole and Countersink Production in Polycrystalline Superhard Inserts

Solution Overview

Problem

Current methods for manufacturing superhard cutting inserts with integral clamping holes are inefficient due to the need for extensive electrical discharge grinding, which increases costs and time, and are not scalable for large quantities, especially when trying to maintain uniformity across different grades of polycrystalline cubic boron nitride (PCBN) and polycrystalline diamond (PCD).

Innovation Solution

A method that simultaneously produces holes and countersinks in polycrystalline superhard material inserts using a laser machine, wire electrical discharge machine, and electrical discharge grinding machine, minimizing the use of electrical discharge grinding and allowing for the same process to be applied to all grades, with the ability to sever inserts with relief angles in a single setup, reducing the need for multiple electrodes and optimizing the use of disc utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If electrical discharge grinding is used to produce holes and countersinks in superhard material inserts, then manufacturing precision is improved, but manufacturing time and cost increase significantly

Engineering Contradiction:

Improvehole and countersink precisionVSAvoidmanufacturing time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The manufacturing process is segmented into multiple stages: roughing with laser drilling, intermediate shaping with wire electrical discharge machining, and final finishing with electrical discharge grinding. This segmentation allows each process to optimize for its specific function, reducing total manufacturing time while maintaining precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The laser drilling process performs preliminary action by creating the initial hole structure and removing the majority of material before electrical discharge processes are applied. This preliminary material removal significantly reduces the subsequent grinding time and complexity.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If electrical discharge grinding is used to produce holes and countersinks in superhard material inserts, then manufacturing precision is improved, but manufacturing cost increases

Engineering Contradiction:

Improvehole and countersink precisionVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The manufacturing process is segmented into multiple stages: roughing with laser drilling, intermediate shaping with wire electrical discharge machining, and final finishing with electrical discharge grinding. This segmentation allows each process to optimize for its specific function, reducing total manufacturing time while maintaining precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The process replaces extensive mechanical electrical discharge grinding with a combination of laser thermal processing and wire electrical discharge machining. This substitution reduces the demand for expensive electrical discharge grinding operations while achieving the required precision through complementary processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If multiple electrodes are used in electrical discharge machining, then manufacturing flexibility is improved, but device complexity increases

Engineering Contradiction:

Improvemanufacturing flexibilityVSAvoidelectrode management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The wire electrical discharge machining process uses a single continuous wire electrode that can be programmed to create multiple different hole patterns and countersink geometries on the same workpiece. This single electrode performs multiple functions that would traditionally require multiple specialized electrodes, reducing device complexity while maintaining flexibility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The process achieves manufacturing flexibility by changing electrical discharge parameters (current, pulse duration, wire tension, feed rate) and programming coordinates rather than physically changing electrodes. This allows adaptation to different insert geometries and hole configurations without the complexity of managing multiple electrodes.

Inventive Principle:

Principle #35Parameter changes

4Productivity

If laser drilling is used for hole production, then productivity is improved, but manufacturing precision may be compromised

Engineering Contradiction:

Improvehole production speedVSAvoidhole geometry precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The manufacturing process is segmented into multiple stages: roughing with laser drilling, intermediate shaping with wire electrical discharge machining, and final finishing with electrical discharge grinding. This segmentation allows each process to optimize for its specific function, reducing total manufacturing time while maintaining precision.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The laser drilling process performs preliminary action by creating the initial hole structure and removing the majority of material before electrical discharge processes are applied. This preliminary material removal significantly reduces the subsequent grinding time and complexity.

Inventive Principle:

Principle #10Preliminary action

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

This method reduces grinding costs and time by minimizing the amount of superhard material removed and allows for more efficient production of tool inserts that meet ISO standards, maintaining accuracy and consistency across different grades, thereby simplifying the manufacturing process and achieving economic benefits in large-scale production.

Implementation Method 1

The holes are produced by using a laser machine

Methodology Applied

Scientific EffectLaser: Laser

Implementation Method 2

forming the holes using a laser machine

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

wire electrical discharge machine

Methodology Applied

Scientific EffectElectrical discharge machining: Electrical Discharge Machining

Implementation Method 4

electrical discharge grinding machine

Methodology Applied

Scientific EffectElectrical discharge grinding: Electrical Discharge Machining

Data Source

PatentEP2678129B1Method of producing holes and countersinks in polycrystalline bodies

Publication Date: 2017.07.19 DIAMOND INNOVATIONS INC

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AI summary

A method of producing at least one through-hole and countersink in at least one ultrahard insert including the steps of providing a body (28, 30, 32, 34) having a first major surface (12) and an opposite second major surface (14); forming at least one pilot hole (28) in said body using a laser, wherein said at least one pilot hole extends from said first major surface to the opposite second major surface of said body;cutting said pilot hole using a wire electrical discharge machine (WEDM) to produce a straight cylindrical portion (26) and top conical portion (22); forming a countersink (24) on at least one side of said body using an electrical discharge grinding machine (EDG); and severing said at least one ultrahard insert from said body forming a finished insert, wherein said finished insert includes a through-hole and a countersink.