Motor Vehicle Control Device with Prestressing Means

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Solution Overview

Problem

Existing motor vehicle control devices with force sensors face issues of non-uniform actuation force, excessive strain requirements, and instability due to the need for precise center pressing, which affects ergonomic comfort and operational efficiency.

Innovation Solution

Incorporating a prestressing means made of flexible material between the force sensor's sensitive surface and the facade, which exerts a prestressing pressure to shift the operating zone and reduce the deformation stroke necessary for activation, allowing for more precise and uniform pressure detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the force sensor is used without prestressing means, then the structure is simple, but the actuating force is non-uniform and excessive strain is required for activation

Engineering Contradiction:
Improveactuating force uniformityVSAvoidstructure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The prestressing means applies a preliminary prestress to the force sensor before actual operation, pre-positioning the sensitive surface in an optimal state. This preliminary action ensures that when the user presses the control, the force sensor is already in a state that provides uniform actuating force across the deformable zone, eliminating the need for precise center pressing while maintaining structural simplicity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The prestressing means changes the stress state parameter of the force sensor by applying a controlled prestress. This parameter change shifts the operating point of the force sensor to a region where the relationship between applied force and sensor response is more linear and uniform, reducing the excessive strain required for activation while maintaining ease of manufacture.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the deformable zone is made more rigid for quality and stability, then stability improves, but the deformation stroke required for activation increases

Engineering Contradiction:
Improvefacade stabilityVSAvoiddeformation stroke
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The prestressing means acts as a counterbalancing mechanism that applies a prestress force to compensate for the increased rigidity of the facade. This counter-stress pre-loads the force sensor, creating a state where less additional deformation is needed to reach the activation threshold, thereby reducing the required deformation stroke while maintaining facade stability.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

By applying prestress beforehand, the system pre-prepares the force sensor to be closer to its activation state. This preliminary action means that when the user applies force during normal operation, the sensor requires less additional deformation to trigger the control function, effectively reducing the deformation stroke without compromising facade rigidity.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the operating zone is shifted using prestressing means, then the deformation stroke is reduced, but the device complexity increases

Engineering Contradiction:
Improveactivation response speedVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The prestressing means applies stress locally to the force sensor in specific regions, creating zones of different stress states. This localized prestressing shifts the operating zone of the force sensor to optimize responsiveness in critical areas while maintaining overall device simplicity. The local quality change allows rapid activation response without requiring complex system-wide modifications.

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

This solution enables immediate and precise resistance variation detection with reduced deformation stroke, enhancing ergonomic comfort and operational efficiency by ensuring consistent activation with lower pressure requirements and improved stability.

Implementation Method 1

a prestressing means arranged on said sensitive surface to exert a prestress bearing pressure on said sensitive surface in order to shift the operating zone of the force sensor

Methodology Applied
Scientific EffectPrestress: Mechanical Force

Implementation Method 2

force sensors using pressure sensitive resistors (also known as 'FSR' sensor for 'Force Sensing Resistor') have made significant progress. The sensitive surfaces of the force sensors make it possible to detect a simple pressure from the driver's finger

Methodology Applied
Scientific EffectPressure sensitive resistance: Piezoresistive Effect

Data Source

PatentEP2678183B1Motor vehicle control device
Publication Date: 2016.04.06 VALEO SYST THERMIQUES SAS
  • EP2678183B1 patent drawingFigure 1~3

AI summary

The present invention relates to a control device for a motor vehicle comprising: - at least one force sensor (2) having at least one surface sensitive to a bearing pressure (4a, 4b, 4c), a façade (3) comprising at least one deformable region (3a, 3b, 3c) associated with said sensitive surface (4a, 4b, 4c) of said force sensor (2), characterized in that it further comprises a preloading means(5a, 5b, 5c, 5d) arranged on said sensitive surface (4a, 4b, 4c) to apply a preloading pressure (Pc) to said sensitive surface (4a, 4b, 4c) in order to offset the operating zone of the force sensor (2).