Electric Tool Torque Correlation for Reliable Tightening Measurement

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Solution Overview

Problem

The reliability of tightening torque values measured by electric tools is not adequately improved by existing technologies, which often rely on single measurement methods and lack comprehensive management systems.

Innovation Solution

An electric tool system that includes an electric tool with a tightening unit and a sensor to measure tightening torque, an inspection device to measure applied tightening force, and an association processor to associate first and second torque measured values, thereby enhancing the reliability of torque measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single sensor measures tightening torque in the electric tool, then the device complexity is reduced, but the measurement precision and reliability of torque values deteriorate

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent combines multiple measurement systems (sensor in electric tool and measuring unit in inspection device) into an integrated measurement network. The association processor merges data from both sources to produce a comprehensive torque measurement that overcomes the limitations of single-sensor measurement, thereby improving measurement precision while maintaining manageable system complexity through systematic integration.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The association processor acts as an intermediary that receives measurement data from both the sensor in the electric tool and the measuring unit in the inspection device. It processes and correlates these measurements, using the first torque measured value and second torque measured value to determine tool condition and calibration status, thereby enhancing measurement reliability without requiring direct complex interaction between the measurement devices.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If multiple measurement systems are integrated to improve torque measurement reliability, then the measurement precision improves, but the device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The association processor serves multiple functions: it receives torque measurements from both the sensor and measuring unit, determines tool condition based on correlated measurements, manages calibration processes, and outputs comprehensive measurement results. This multi-functionality consolidates what could be separate complex systems into a single versatile processing unit, improving reliability while controlling overall system complexity.

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

Solution Approach 2:

The system implements feedback mechanisms where the association processor continuously monitors torque measurements from both sources, compares the first torque measured value with the second torque measured value, and uses this feedback to determine tool condition and trigger calibration when necessary. This feedback loop ensures high reliability by continuously validating measurements while maintaining manageable complexity through automated decision-making.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the electric tool is frequently calibrated to maintain accurate torque measurements, then the measurement precision is maintained, but the productivity decreases

Engineering Contradiction:
Improvemeasurement precisionVSAvoidproductivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs preliminary condition assessment by continuously monitoring torque measurements from both the sensor and measuring unit through the association processor. By determining tool condition in advance based on correlated measurements, the system can predict when calibration is actually needed, avoiding unnecessary calibration operations and maintaining productivity while ensuring measurement precision is maintained when required.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The association processor automatically monitors torque measurements, compares first torque measured value with second torque measured value, determines tool condition, and manages calibration timing without requiring constant manual intervention. This self-service capability maintains measurement precision through automated condition-based calibration decisions, reducing productivity loss associated with frequent manual calibration while ensuring accuracy is maintained.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3995259B1Electric tool system, electric tool, and method for managing electric tool
Publication Date: 2025.03.05 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3995259B1 patent drawingFigure 1
  • EP3995259B1 patent drawingFigure 2
  • EP3995259B1 patent drawingFigure 3

AI summary

An object of the present disclosure is to improve the reliability of a tightening torque value measured by an electric tool. An electric tool system (10) includes an electric tool (1) and an inspection device (2). The electric tool (1) includes: a tightening unit (11) configured to tighten a workpiece onto an attaching target by driving force of a drive source; and a sensor (12) configured to measure a tightening torque provided by the tightening unit (11). The inspection device (2) includes a measuring unit (21) configured to measure tightening force applied from the tightening unit (11). The electric tool system (10) further includes an association processor (F1) configured to associate a first torque measured value with a second torque measured value. The first torque measured value corresponds to a measurement result by the sensor (12). The second torque measured value corresponds to a measurement result by the measuring unit (21).