Self-Centering Decoupling Shim for Disc Brake Caliper Eccentricity

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Solution Overview

Problem

In motor vehicle disc brakes, the decoupling plate can become eccentric during braking, limiting its sliding travel and preventing the desired freedom of movement between the brake pad and caliper, which compromises the decoupling function.

Innovation Solution

Incorporating elastic return means, such as two springs made in one piece with the decoupling plate, to return the plate to a central position relative to the pad support, ensuring it can slide freely and maintain decoupling functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a decoupling plate is interposed between the piston and pad support to prevent piston penetration into the insulating coating, then the decoupling function is improved, but the plate may become eccentric and limit sliding travel

Engineering Contradiction:
Improvedecoupling functionVSAvoidsliding freedom
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A centralizing element is introduced as an intermediary component between the decoupling plate and the pad support. This element acts as a mediator that guides the decoupling plate during its sliding movement, ensuring it returns to and remains in the central position relative to the pad support, thus preventing eccentricity while maintaining the decoupling function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system transitions from a static decoupling plate to a dynamic one that can slide freely during braking. The centralizing element enables the plate to move dynamically during braking operations while automatically returning to its central position when not in use, optimizing both decoupling performance and sliding freedom.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the decoupling plate is allowed to slide freely to maintain freedom of movement, then ease of operation is improved, but the plate may become eccentric and compromise decoupling functionality

Engineering Contradiction:
Improvesliding freedomVSAvoiddecoupling function
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The centralizing element provides continuous feedback to the decoupling plate during its sliding movement. As the plate moves away from the central position, the centralizing element guides it back, creating a self-correcting mechanism that ensures the plate remains properly positioned throughout its operational range, thus maintaining both sliding freedom and decoupling reliability.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If elastic return means are added to center the decoupling plate, then positioning accuracy is improved, but device complexity increases

Engineering Contradiction:
Improveplate positioningVSAvoidnumber of components
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The centralizing element is designed to be integrated with either the decoupling plate or the pad support structure. By merging the centralizing function with an existing component rather than adding a completely separate mechanism, the solution achieves precise plate positioning while minimizing the increase in overall device complexity.

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

The elastic return mechanism ensures the decoupling plate remains in a central position, allowing for unrestricted sliding and effective decoupling between the piston and pad support, maintaining the desired freedom of movement and sound insulation during braking.

Implementation Method 1

the brake comprises means for elastic return of the decoupling plate to a central position of rest with respect to the pad support

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the pad support comprises a sound-absorbing coating which is intended to thermally insulate the piston from the brake pad to prevent the calories produced by the tightening of the pad against the disc during braking from being transmitted to the caliper piston

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

the leaf springs are intended to reduce the vibrations that exist between the brake pad and the caliper by allowing a certain freedom of movement of the brake pad in the caliper

Methodology Applied
Scientific EffectVibration damping: Damping

Data Source

PatentEP1914437B1Disc brake having a self centering shim
Publication Date: 2009.10.07 ROBERT BOSCH GMBH
  • EP1914437B1 patent drawingFigure 1~2
  • EP1914437B1 patent drawingFigure 3~5

AI summary

The brake has a decoupling plate (34) interposed axially between a pad support (21) and a locking element (16). The plate is mounted slidingly in a transversal plane with respect to the support for permitting displacement of a brake pad (14) with respect to the element during braking. Elastic springs (36) return the plate towards a central rest position with respect to the pad support. Contacts (40) of the brake pad and a longitudinal bore (42) guide the displacement of the decoupling plate with respect to the pad support during sliding of the plate.