Wireless Force Transducer for Joining Module

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Solution Overview

Problem

Existing electromechanical joining modules face limitations in force measurement accuracy due to bearing friction, inertial mass, and complex cable connections, which lead to reduced service life and increased maintenance needs.

Innovation Solution

Integration of a force transducer with sensor electronics at the ram end for wireless near-field telemetry, utilizing a plunger coil for energy supply and data transmission, eliminating errors from friction and inertial mass and avoiding cable damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a force measuring device is integrated into the housing of the joining module, then force measurement is enabled, but measurement accuracy is limited due to bearing friction, force shunts, and inertial mass

Engineering Contradiction:
Improveforce measurement accuracyVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The force transducer is extracted from the stationary housing and relocated to the moving ram. This separation removes the measurement system from the sources of error (bearing friction, force shunts in the housing) and inertial mass affecting stationary measurements, enabling accurate dynamic force measurement directly at the point of application.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A wireless communication system serves as an intermediary between the moving force transducer and the stationary control unit. This mediator transmits measurement data without physical cable connections, eliminating cable-related failures while maintaining reliable data transfer throughout the ram's movement range.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a force transducer is integrated into the joining body, then force measurement accuracy is improved, but the cable connection becomes mechanically complex and prone to failure

Engineering Contradiction:
Improveforce measurement accuracyVSAvoidcable connection complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The mechanical cable connection system is replaced with an electromagnetic wireless communication system. The force transducer communicates with the control unit via radio frequency signals, eliminating all mechanical cable components that would otherwise be subject to wear, entanglement, and failure during the ram's linear movement.

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

3Use of energy by moving object

If a cable connection is used for the force transducer, then power and data transmission are enabled, but the service life is severely limited due to mechanical wear

Engineering Contradiction:
Improvepower transmissionVSAvoidservice life
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

Both power and data transmission are achieved wirelessly through electromagnetic fields. The control unit transmits power signals and receives measurement data via radio frequency communication, completely eliminating the need for physical cable connections that would otherwise experience mechanical wear and limit service life.

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

4Measurement precision

If the force transducer is attached at the end of the ram with wireless near-field telemetry, then measurement accuracy is improved and service life is extended, but additional components (plunger coil, sensor electronics) are added

Engineering Contradiction:
Improveforce measurement accuracyVSAvoidsystem structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The plunger coil serves multiple functions simultaneously: it acts as the actuator that drives the ram's linear movement, serves as the antenna for wireless power reception through near-field coupling, and functions as the communication channel for data transmission. This multi-functionality reduces the need for separate dedicated components.

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

Solution Approach 2:

The sensor electronics are integrated directly into the force transducer assembly at the ram end, combining the measurement function with the wireless communication interface. This integration eliminates separate cable connectors and reduces the overall component count while maintaining all necessary functions.

Inventive Principle:
Principle #5Merging (Combining)

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 provides high-accuracy, maintenance-free force measurements with extended service life, independent of movement cycles, and simplifies the structure for customer-specific adjustments without additional effort.

Implementation Method 1

the sensor electronics are connected to a plunger coil, which extends over the entire extendable area of the plunger. The stator has stator electronics near the plunger coil for the wireless supply of energy to the sensor electronics

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the sensor electronics are connected to a plunger coil, which extends over the entire extendable area of the plunger. The stator has stator electronics near the plunger coil for the wireless supply of energy to the sensor electronics and for receiving the measurement data using near-field telemetry

Methodology Applied
Scientific EffectNear-field telemetry: Electromagnetic Induction

Data Source

PatentEP2456594B1Electromechanical joining module having a force transducer
Publication Date: 2018.01.24 KISTLER HLDG AG
  • EP2456594B1 patent drawingFigure 1a~2
  • EP2456594B1 patent drawingFigure 3a~5

AI summary

The invention relates to an electromechanical joining module for applying a linear force to a joining element, comprising a stator (2), which represents the stationary part of the joining module, a tappet (3), which can be linearly extended out of the stator (2) and which has an outer tappet end (4), and a force transducer (5) for detecting forces that are applied to the joining element during the operation of the tappet end (4). According to the invention, the force transducer (5) is attached in the area of the tappet end (4) and has sensor electronics (7) for wirelessly transmitting measurement data by means of near-field and far-field telemetry.