Weighing Device Through-Hole Laser Processing for Eccentric Load Errors

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Solution Overview

Problem

Existing laser processing methods for weighing devices expose the monolithic structure outside the housing member, leading to potential eccentric load errors due to inadequate eccentric load adjustment after assembly.

Innovation Solution

A weighing device with a housing member containing through holes for guiding laser light to the strain body, combined with an adjustment device that irradiates and processes the strain body to reduce eccentric load errors, using a control unit to determine optimal irradiation positions and amounts based on measured weighing values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If laser processing is performed before housing assembly, then manufacturing efficiency is improved, but eccentric load error increases due to inability to perform adjustment after assembly

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoideccentric load error
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by providing through-holes in the housing member during the manufacturing stage, enabling future laser processing access. This preliminary structural preparation allows the strain body to be processed after housing assembly, resolving the contradiction between early processing efficiency and later adjustment precision.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the strain body is exposed outside the housing member, then laser processing access is improved, but measurement accuracy deteriorates due to eccentric load error

Engineering Contradiction:
Improvelaser processing accessVSAvoidweight measurement accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements nesting by placing the strain body inside the housing member while providing through-holes that allow laser light to reach the strain body from outside. This nested configuration maintains the protective enclosure while enabling external processing access, resolving the contradiction between ease of operation and measurement precision.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The through-holes in the housing member act as intermediaries, transmitting laser light from the external processing environment to the internal strain body. This intermediary structure enables laser processing access without requiring the strain body to be exposed outside the housing, thus maintaining measurement accuracy while improving operational ease.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the housing member is made opaque for protection, then environmental protection is improved, but laser light transmission to strain body deteriorates

Engineering Contradiction:
Improveenvironmental protectionVSAvoidlaser light transmission
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The housing member is segmented with localized through-holes that provide laser light transmission paths while maintaining the overall opaque protective structure. This segmentation allows selective transparency where needed (for laser access) while preserving opacity for environmental protection, resolving the contradiction between protection and energy transmission.

Inventive Principle:
Principle #1Segmentation

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

Effectively reduces eccentric load errors by accurately adjusting the strain body through controlled laser processing, ensuring precise weight measurements.

Implementation Method 1

irradiating the recess with laser light so that the value measured by the force sensor of the weighing cell becomes the expected result

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentEP4614121A1Weighing device, weighing adjustment device, and weighing adjustment method
Publication Date: 2025.09.10 SHINKO DENSHI
  • EP4614121A1 patent drawingFigure 1
  • EP4614121A1 patent drawingFigure 2
  • EP4614121A1 patent drawingFigure 3

AI summary

The weighing device 1A according to one embodiment includes a weighing pan 2 on which an object to be weighed is placed, a load cell 4 having a strain body 5 disposed below the weighing pan 2 so that a load of the object placed on the weighing pan 2 is applied to the strain body 5, and a housing member 3 accommodating the load cell 4. The housing member 3 is provided with a through-hole 31a for guiding laser light irradiated from the outside of the housing member 3 to the strain body 5 disposed inside the housing member 3.