Load Measuring Device for Construction Machine with Cylinder Balance Validation

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Solution Overview

Problem

Conventional load measuring apparatuses for construction machines, such as dump trucks, face challenges in maintaining precise load measurement due to unstable longitudinal and lateral balance caused by varying suspension cylinder pressures and inappropriate maintenance, leading to measurement errors, especially when only three or two out of four suspension cylinders bear the load.

Innovation Solution

A load measuring apparatus with a loading weight confirmation module that calculates and outputs loading weight only when all suspension cylinders have loads equal to or greater than specified values, ensuring precise measurement by invalidating calculations when any cylinder's load is below the threshold, thereby maintaining vehicle balance and preventing large measurement errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If load measurement is performed using conventional suspension cylinders, then load measurement capability is provided, but measurement precision deteriorates when suspension cylinder pressure is below specified value due to unstable vehicle balance

Engineering Contradiction:
Improveloading weight measurement precisionVSAvoidmeasurement reliability under varying suspension pressure
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The loading weight confirmation module performs preliminary validation by checking whether loads of all suspension cylinders are equal to or larger than specified values before the loading weight arithmetic module calculates the loading weight. This preliminary check prevents inaccurate measurements from being output, ensuring that only reliable measurements are provided when vehicle balance is stable.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If loading weight calculation is performed without checking suspension cylinder loads, then measurement coverage is increased, but measurement precision deteriorates due to inclusion of inaccurate measurements

Engineering Contradiction:
Improvemeasurement output volumeVSAvoidloading weight measurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The loading weight confirmation module provides feedback by validating suspension cylinder load conditions before allowing the loading weight arithmetic module to perform calculations. This feedback mechanism ensures that only measurements taken under stable vehicle balance conditions (when all suspension cylinders have sufficient load) are output, maintaining high measurement precision while still providing comprehensive measurement coverage when conditions are appropriate.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3306283B1Load measuring device for construction machine
Publication Date: 2020.12.23 HITACHI CONSTRUCTION MACHINERY CO LTD
  • EP3306283B1 patent drawingFigure 1~2
  • EP3306283B1 patent drawingFigure 3
  • EP3306283B1 patent drawingFigure 4

AI summary

An object of the present invention is to provide a new load measuring apparatus for a construction machine that enables more enhancing measurement precision by monitoring a condition of a suspension cylinder. The load measuring apparatus for a construction machine according to the present invention is provided with a loading weight arithmetic module 111 that calculates a loading weight on the basis of loads of plural suspension cylinders 51 and a loading weight confirmation module 112 that outputs the calculated loading weight when the loads of the suspension cylinders 51 are all equal to or larger than a specified value and makes the calculated loading weight ineffective without outputting the loading weight when any one of the loads is below the specified value.