Adjustable Optical Axis Defect Inspection for Inclined Pipe Threads

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Solution Overview

Problem

Existing defect inspecting apparatuses are unable to accurately inspect defects on inclined load faces and thread bottom faces of pipes, and fail to inspect defects on the outer peripheral surface of lip parts, leading to potential oil leakage and pipe damage.

Innovation Solution

The apparatus employs multiple light sources and image capture devices with adjustable optical axes to illuminate and capture images of inclined surfaces, ensuring that reflection light is received optimally, allowing for clear imaging and defect detection on the outer peripheral surface of the lip part, load face, and thread bottom face inspection zones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the optical axis of the image capture device coincides with the direction perpendicular to the pipe axis direction, then the device structure is simple, but the device cannot grab the image of the load face inclined inwardly in the pipe axis direction

Engineering Contradiction:
Improvedevice structureVSAvoidimage capture capability
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent makes the optical axis of the image capture device adjustable rather than fixed, allowing it to be dynamically oriented at an angle that captures the inclined load face. This transforms a static structure into a dynamic one that can adapt to different inspection requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces an angular dimension to the optical axis orientation, allowing the image capture device to inspect surfaces in three-dimensional space rather than being constrained to a single perpendicular direction. This enables capture of the inclined load face by rotating the optical axis away from the pipe axis perpendicular direction.

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

2Strength

If the load face is inclined inwardly in the pipe axis direction, then the structural design accommodates stress distribution, but the reflection light cannot be received by the image capture device with perpendicular optical axis

Engineering Contradiction:
Improvestress distributionVSAvoidreflection light reception
Core Design Contradiction:
StrengthVSLoss of information

Solution Approach 1:

The optical axis is made adjustable to dynamically align with the inclined load face, enabling the image capture device to receive reflection light from surfaces oriented at various angles. This resolves the information loss caused by the fixed perpendicular orientation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the orientation parameter of the optical axis from a fixed perpendicular angle to an adjustable angle that can be optimized for receiving reflection light from the inclined load face, thereby maintaining both structural integrity and inspection capability.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If a single light source and image capture device are used, then the device complexity is reduced, but the inspection coverage of multiple zones (lip part, load face, thread bottom face) is insufficient

Engineering Contradiction:
Improvenumber of componentsVSAvoidinspection coverage
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent employs adjustable optical axes for light sources and image capture devices, allowing a single component to dynamically target multiple inspection zones (lip part, load face, thread bottom face) by changing its orientation angle, thereby achieving multi-zone coverage without increasing component count.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The inspection device is designed with universal capability to inspect multiple zones through adjustable optical axes, allowing the same hardware configuration to serve multiple inspection functions by reorienting the optical path to different surfaces.

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

This solution enables high-accuracy defect inspection on inclined surfaces, preventing oil leakage and pipe damage by effectively capturing images of the lip part, load face, and thread bottom face inspection zones, even when the load face is inclined inwardly.

Implementation Method 1

a first light source for illuminating the outer peripheral surface of the lip part

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

an image capture device for grabbing the image of the outer peripheral surface of the pipe by receiving the reflection light reflected by the outer peripheral surface of the pipe

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2530457B1Defect inspection device
Publication Date: 2021.03.17 NIPPON STEEL CORPORATION
  • EP2530457B1 patent drawingFigure 1
  • EP2530457B1 patent drawingFigure 2A~2B
  • EP2530457B1 patent drawingFigure 3

AI summary

There is provided a defect inspecting apparatus capable of inspecting defects on a load face and in a thread bottom face inspection zone of a pipe or tube in which the load face is inclined inwardly in the pipe or tube axis direction, and also capable of inspecting a defect on the outer peripheral surface of a lip part. The defect inspecting apparatus includes a first light source 2, a first image capture device 3 that receives the reflection light emitted from the first light source and reflected by the outer peripheral surface of a lip part 102 to grab the image of the outer peripheral surface of the lip part, a second light source 7, a second image capture device 8 that receives the reflection light emitted from the second light source and reflected by a load face 103 to grab the image of the load face, a third light source 9, a third image capture device 10 that receives the reflection light emitted from the third light source and reflected by a thread bottom face inspection zone 106 to grab the image of the thread bottom face inspection zone, and an inspection device for inspecting defects on the outer peripheral surface of the lip part, on the load face, and in the thread bottom face inspection zone by processing the captured images grabbed by the first to third image capture devices.