Force Sensor Assembly with Integrated Strain Gauges

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Solution Overview

Problem

Existing force sensors for axial force measurement, particularly in automotive applications, are complex and costly to manufacture and assemble, lacking a straightforward and cost-effective solution.

Innovation Solution

A force sensor assembly comprising a force ring with sensing elements, a printed circuit board, a covering plate, and a sensor cap, which can be easily assembled by stacking and welding components, with strain gauges measuring deformation and electronic components for signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional force sensor designs are used, then measurement function is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsensor structure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple functional components (force ring with strain gauges, PCB with electronics, covering plate for protection, and sensor cap for sealing) into a single integrated assembly. The force ring integrates both the structural element and the sensing element (strain gauges), eliminating the need for separate mounting brackets and reducing assembly steps while maintaining measurement functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The force ring serves multiple functions simultaneously: it acts as the structural load-bearing component, the sensing element (through integrated strain gauges), and the mounting base for the PCB and covering plate. This multi-functionality reduces the total number of parts needed and simplifies the overall sensor structure.

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

2Ease of manufacture

If traditional force sensor designs are used, then measurement function is achieved, but manufacturing cost increases

Engineering Contradiction:
Improvemanufacturing cost-effectivenessVSAvoidsensor assembly complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines multiple functional components (force ring with strain gauges, PCB with electronics, covering plate for protection, and sensor cap for sealing) into a single integrated assembly. The force ring integrates both the structural element and the sensing element (strain gauges), eliminating the need for separate mounting brackets and reducing assembly steps while maintaining measurement functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor is divided into distinct modular components (force ring assembly, PCB assembly, covering plate, sensor cap) that can be manufactured separately and then easily assembled. This segmentation allows for standardized manufacturing processes and simplifies quality control while reducing overall complexity.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If strain gauges are positioned on force ring regions, then axial force measurement is enabled, but component strain increases

Engineering Contradiction:
Improveaxial force measurement capabilityVSAvoidcomponent strain tolerance
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The strain gauges are strategically positioned on specific regions of the force ring where stress concentration occurs during axial loading. By placing sensors only in these critical local areas rather than uniformly across the entire ring, the design achieves accurate measurement while minimizing the overall strain burden on the component structure.

Inventive Principle:
Principle #3Local quality

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 assembly is simpler, more cost-effective to produce, and suitable for automotive applications, such as electromagnetic brake systems, offering reliable axial force measurement with minimal strain on components.

Implementation Method 1

a force ring provided with at least two sensing elements configured to sense the deformation of the force ring

Methodology Applied
Scientific EffectStrain gauge measurement: Piezoresistive Effect

Implementation Method 2

welding an outer rim and an inner rim of a sensor cap covering the printed circuit board and covering plate to the force ring

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP2546625B1Force sensor assembly and method for assembling a force sensor assembly
Publication Date: 2016.04.13 SENSATA TECHNOLOGIES INC
  • EP2546625B1 patent drawingFigure 1
  • EP2546625B1 patent drawingFigure 2~3
  • EP2546625B1 patent drawingFigure 4~5

AI summary

Force sensor assembly and method of manufacturing such a force sensor assembly. The force sensor assembly has axis of measurement along an axial direction (14) of the force sensor assembly (1) and comprises a force ring (2) provided with at least two sensing elements (3), a printed circuit board (4) having electronic components (5) thereon, a covering plate (6) for holding the printed circuit board (4) onto the force ring (2), and a sensor cap (7) covering the printed circuit board (4) and covering plate (6) and attached to the force ring (2). Manufacturing is easily accomplished using stacking, fixing and welding.