Coated Sheet Burring After Local Coating Removal

Solution Overview

Problem

Existing burring methods using friction heat on coated metal surfaces, particularly those with zinc-based coatings, fail to form flanges effectively due to interference from the coating, leading to defects such as fractured flanges.

Innovation Solution

A method involving the removal of the coating layer before burring, allowing for the effective conduction of friction heat and enabling the formation of a through hole and flange by rotating the burring tool through the coated metal surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a coating layer is present on the metal surface during burring, then the surface is protected from corrosion and wear, but the friction heat cannot be effectively conducted, leading to failed flange formation

Engineering Contradiction:

Improveflange formation qualityVSAvoidcoating layer interference

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The coating layer is removed in advance from the burring region before the burring operation begins. This preliminary removal action ensures that the metal surface is ready to receive and conduct friction heat effectively, allowing proper flange formation without the interference of the coating layer.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coating layer is selectively removed only from the specific region where burring will occur, while other areas of the workpiece may retain their protective coating. This localized treatment ensures that the coating's protective function is maintained where needed while eliminating its interference in the burring zone.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the coating layer is removed before burring, then friction heat can be effectively conducted for proper flange formation, but an additional processing step is required

Engineering Contradiction:

Improveflange qualityVSAvoidprocess steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The coating removal operation is integrated with the burring process by positioning the workpiece and coordinating the operations so that coating removal and subsequent burring are performed in a coordinated manner, reducing the need for separate, isolated processing steps and simplifying the overall manufacturing flow.

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If friction heat is applied on a coated surface, then the coating provides surface protection, but the heat conduction is blocked, causing defective flange formation

Engineering Contradiction:

Improvesurface protectionVSAvoidfriction heat conduction

Core Design Contradiction:

Object-affected harmful factorsVSTemperature

Solution Approach 1:

The coating layer is removed in advance from the burring region before the burring operation begins. This preliminary removal action ensures that the metal surface is ready to receive and conduct friction heat effectively, allowing proper flange formation without the interference of the coating layer.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The coating layer is selectively removed only from the specific region where burring will occur, while other areas of the workpiece may retain their protective coating. This localized treatment ensures that the coating's protective function is maintained where needed while eliminating its interference in the burring zone.

Inventive Principle:

Principle #3Local quality

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

Ensures the formation of a favorable through hole and flange without defects, facilitating the subsequent formation of internal threads on the flange surface.

Implementation Method 1

The frictional heating that occurs between the drilling tool and the metal sheet or metal pipe wall, and the friction pressure applied from the drilling tool to the metal sheet or metal pipe wall, melt the metal.

Methodology Applied

Scientific EffectFriction heating: Friction

Implementation Method 2

The first coating layer in a first region of the plate portion is removed

Methodology Applied

Scientific EffectCoating removal:

Data Source

PatentUS20250296176A1Workpiece processing method, machine tool, and non-transitory computer-readable recording medium

Publication Date: 2025.09.25 YAMAZAKI MAZAK KK

AI summary

A workpiece processing method includes preparing a workpiece having a plate portion that includes a base material and a first coating layer. The base material has a first surface and a second surface opposite to the first surface in a direction along a thickness of the base material. The first coating layer is provided on the second surface of the base material. The first coating layer in a first region of the plate portion is removed. A burring tool is moved in a first direction from the first surface toward the second surface in a rotating state to burr the plate portion so as to form a through hole and a flange in the first region of the plate portion after removing the first coating layer in the first region.