Electroactive Polymer Reaction Disc for Adjustable Brake Pedal Resistance

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Solution Overview

Problem

Hydraulic brake systems in vehicles face challenges in varying pedal resistance effectively, as conventional reaction discs are not compressible and lack adjustable properties to enhance pedal feel and braking performance.

Innovation Solution

Integration of two independently controllable electroactive polymer actuators arranged coaxially within a reaction disc, allowing for adjustable pedal resistance by altering the disc's properties through radial expansion and contraction, which is achieved by energizing one actuator to force elastomer material outward and the other to compress axially, within a predetermined outer circumference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional reaction disc material is used, then structural simplicity is maintained, but pedal resistance cannot be adjusted

Engineering Contradiction:
Improvepedal resistance adjustmentVSAvoidreaction disc structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The reaction disc transitions from a static, fixed-property component to a dynamic, adjustable component through the integration of electroactive polymer actuators. These actuators enable the reaction disc to change its mechanical properties (stiffness, damping) in real-time based on operating conditions, allowing pedal resistance adjustment while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the physical parameters of the reaction disc by incorporating electroactive polymer actuators that can alter the disc's stiffness and damping characteristics. By controlling the electrical voltage applied to these actuators, the system can dynamically adjust the pedal resistance without requiring multiple different reaction disc components.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If polymer actuators are added to enable resistance adjustment, then adaptability improves, but integration complexity increases

Engineering Contradiction:
Improveoperational flexibilityVSAvoidintegration into braking system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention merges the polymer actuators with the existing reaction disc structure, combining two previously separate functions (structural support and resistance adjustment) into a single integrated component. This approach reduces the number of separate parts and simplifies integration into the braking system while maintaining operational flexibility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reaction disc is designed to serve multiple functions simultaneously: it maintains its primary structural role in the braking system while also incorporating polymer actuators that enable dynamic resistance adjustment. This multi-functionality reduces the need for additional separate components and simplifies overall system integration.

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

3Force

If outer circumference is limited, then radial expansion is constrained, but axial compression is enhanced

Engineering Contradiction:
Improveaxial compression forceVSAvoidradial expansion area
Core Design Contradiction:
ForceVSArea of stationary object

Solution Approach 1:

The invention applies different constraints to different directions of the reaction disc: the outer circumference is constrained to limit radial expansion, while the axial direction is left free to accommodate compression. This anisotropic constraint strategy enhances axial compression force while maintaining structural integrity, allowing the polymer actuators to effectively adjust pedal resistance through axial deformation.

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 allows for simple and space-saving adjustment of brake pedal resistance based on operating states, improving pedal feel and braking performance by varying the reaction disc's properties, enabling a stronger or linear braking effect without noticeable counterforce, thus enhancing driver experience and system efficiency.

Implementation Method 1

having at least one first electroactive polymer actuator

Methodology Applied
Scientific EffectElectroactive polymer: Electroactive Polymer

Data Source

PatentEP3303081B1Device for varying a pedal resistance, brake system
Publication Date: 2019.04.03 ROBERT BOSCH GMBH
  • EP3303081B1 patent drawingFigure 1
  • EP3303081B1 patent drawingFigure 2~3
  • EP3303081B1 patent drawingFigure 4A~4B

AI summary

The invention relates to a device for varying a pedal resistance of a hydraulic brake system (1), comprising at least one electroactive polymer actuator (15, 16). A reaction disc (10) is provided, which has at least two independently controllable polymer actuators (15, 16) which are arranged coaxially to each other.