Elastomeric Stop Disk for Hydraulic Brake Zero Point Stability

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Solution Overview

Problem

Brake devices without vacuum boosters face challenges in maintaining a stable zero point and reducing impact noise due to low self-damping, with existing solutions like rubber discs and corrugated spring washers failing to provide adequate damping and maintaining a defined zero point.

Innovation Solution

A stop disk with an elastomeric casing and a stiff core, where the casing is overmolded with EPDM polymer and the core is made of metal or fiber-reinforced plastic, allowing for defined compression and path-controlled damping, ensuring a constant zero point and effective noise reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a rubber disc is used for impact damping, then noise is reduced, but the zero point cannot be maintained within the required narrow tolerance due to high elasticity

Engineering Contradiction:
Improveimpact noiseVSAvoidzero point position
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The stop disk combines an elastomeric casing (for damping) with a stiff core made of metal or fiber-reinforced plastic (for dimensional stability). This composite structure allows the outer casing to absorb impact energy while the rigid core maintains the zero point position within narrow tolerances, resolving the contradiction between noise reduction and measurement precision.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If a thermoplastic material stop disk is used, then the zero point is maintained, but the damping effect is too small and the disc deforms over time

Engineering Contradiction:
Improvezero point positionVSAvoidimpact noise
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The invention replaces the homogeneous thermoplastic material with a composite structure consisting of an elastomeric casing and a stiff core. The elastomeric material provides sufficient damping effect to reduce impact noise, while the stiff core prevents deformation over time and maintains the zero point position.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the material parameters by selecting an elastomer with specific damping characteristics and a core material with high stiffness. This parameter optimization ensures both adequate damping effect and long-term dimensional stability, addressing the insufficient damping and deformation issues of thermoplastic materials.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If a corrugated spring washer is used for impact damping, then noise is reduced, but the zero point shifts and requires complex calibration

Engineering Contradiction:
Improveimpact noiseVSAvoidzero point position
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The stop disk combines an elastomeric casing (for damping) with a stiff core made of metal or fiber-reinforced plastic (for dimensional stability). This composite structure allows the outer casing to absorb impact energy while the rigid core maintains the zero point position within narrow tolerances, resolving the contradiction between noise reduction and measurement precision.

Inventive Principle:
Principle #40Composite materials

4Productivity

If the brake pedal is released quickly after braking, then the brake response is fast, but the cylinder piston returns at high speed causing hitting noise

Engineering Contradiction:
Improvebrake response speedVSAvoidhitting noise
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The elastomeric casing of the stop disk acts as a pre-positioned cushioning element that absorbs the impact energy when the cylinder piston returns quickly after braking. This beforehand cushioning allows fast brake response while preventing the hitting noise that would otherwise occur during rapid piston return.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 solution provides reliable, wear-free, and deformation-free damping, maintaining the zero point within narrow tolerances and reducing noise effectively, while being cost-effective and adaptable.

Implementation Method 1

The material for the casing is designed in such a way that at the same time sufficient damping is achieved and at the same time the existing restoring force is sufficient to establish contact between the cylinder piston and the core of the stop disk

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The stop disk can be elastically and reversibly compressed in the axial direction over a defined compression path

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentEP3697653B1Braking device for a hydraulic motor vehicle braking system comprising a stop disc
Publication Date: 2022.08.10 CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
  • EP3697653B1 patent drawingFigure 1
  • EP3697653B1 patent drawingFigure 2
  • EP3697653B1 patent drawingFigure 3a~3b

AI summary

In order to provide an improved braking device (1) without a vacuum booster, in which braking device the zero point of the cylinder piston (3) remains as durably as possible within defined close tolerances and simultaneously the impact noise is reliably reduced, according to the invention the stop disc (5) can be elastically reversibly compressed in the axial direction over a defined compression path (S) and comprises means for delimiting the compression path (S), said delimitation being defined in a path-controlled manner.