Crankshaft Flaw Detection Device for Eccentric Pin Inspection

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Solution Overview

Problem

Current crankshaft inspection methods require extensive manual scanning, making it time-consuming and labor-intensive to detect flaws on crank pins, journal sections, and webs, especially for large crankshafts, and existing automated systems are limited in their ability to inspect crank pins due to their eccentric rotation.

Innovation Solution

A crankshaft flaw detection device with a scanning unit comprising upper and lower side shaft flaw detection heads, a perpendicular surface flaw detection head, and a coupling arm, which allows for automated scanning of crank pins, webs, and journal sections by rotating the crankshaft, enabling the use of probes to detect flaws on all critical areas without displacing from their positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual scanning is used for flaw detection on crankshaft components, then comprehensive inspection coverage is achieved, but inspection time and labor requirements increase significantly

Engineering Contradiction:
Improveflaw detection coverageVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces manual mechanical scanning with an automated ultrasonic inspection system. The probe is positioned to contact the crank pin surface, and the system automatically scans the crank pin, web, and journal section while the crankshaft rotates, eliminating manual labor and significantly reducing inspection time while maintaining comprehensive flaw detection coverage

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The inspection system utilizes the natural rotation of the crankshaft during engine operation or testing to automatically bring different components (crank pin, web, journal section) into the inspection position. The crankshaft's own rotational movement serves the inspection process, eliminating the need for separate positioning mechanisms and reducing overall inspection time

Inventive Principle:
Principle #25Self-service

2Productivity

If automated peripheral scanning is used for journal sections, then inspection efficiency is improved, but crank pin inspection capability is lost due to eccentric rotation

Engineering Contradiction:
Improveinspection efficiencyVSAvoidinspection capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent positions the ultrasonic probe at an angled orientation relative to the crankshaft axis, allowing it to simultaneously inspect the crank pin (which rotates eccentrically), the web, and the journal section. This multi-dimensional positioning enables the single probe to cover all critical areas that would otherwise require multiple specialized inspection stations

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

Solution Approach 2:

The inspection system is designed with a universal probe positioning mechanism that can inspect multiple component types (crank pin, web, journal section) using a single integrated setup. The probe and positioning system are configured to handle the eccentric rotation of the crank pin while simultaneously covering the journal section, making the system versatile for comprehensive crankshaft inspection

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

3Ease of manufacture

If the probe position is fixed relative to the crankshaft axis, then journal section inspection is simplified, but the probe cannot follow the eccentric crank pin movement

Engineering Contradiction:
Improveprobe positioning simplicityVSAvoidcrank pin tracking capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The probe positioning system incorporates dynamic adjustment capabilities that allow the probe to automatically follow the eccentric movement of the crank pin during rotation. The positioning mechanism can dynamically change the probe's radial and axial positions to maintain optimal contact with the crank pin surface throughout its eccentric orbit, while still maintaining the ability to inspect the journal section

Inventive Principle:
Principle #15Dynamics

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 device significantly reduces flaw detection time by automating the scanning process across all critical areas of the crankshaft, achieving an 80% reduction in man-hours required for manual scanning while ensuring precise and comprehensive flaw detection.

Implementation Method 1

a quality inspection (ultrasonic examination) is required for these sections

Methodology Applied
Scientific EffectUltrasonic examination: Ultrasound

Data Source

PatentEP2894471B1Crankshaft flaw detection device
Publication Date: 2019.05.08 KOBE STEEL LTD
  • EP2894471B1 patent drawingFigure 1~2
  • EP2894471B1 patent drawingFigure 3(A)~4(B)
  • EP2894471B1 patent drawingFigure 5(A)~6(B)

AI summary

A crankshaft flaw detection device (1) used for detecting flaws in the crank pin, web, and fillet section of a crankshaft comprises: a pair of shaft flaw detection heads (2, 3) configured so as to be capable of sandwiching the crank pin (C2) therebetween, and having a first probe (2b) capable of detecting flaws on the shaft surface of the crank pin (C2) or a second probe (3b) capable of detecting flaws in a fillet section at the base of the shaft; and a perpendicular surface flaw detection head (4) configured so as to be capable of coming in contact with the crank pin (C2) and having a third probe (4b) capable of detecting flaws in the side surface of the web (C3). The crankshaft flaw detection device (1) is characterized by the perpendicular surface flaw detection head (4) and the pair of shaft flaw detection heads (2, 3) being movable within the perpendicular surface