Disc Brake Elastic Return Spring Wear Compensation

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Solution Overview

Problem

Disc brakes in automotive vehicles experience premature wear and residual torque due to inadequate elastic return of brake pads, leading to increased vehicle consumption and reduced performance, as the rotating disc fails to sufficiently push back the brake pads to their inactive position.

Innovation Solution

The disc brake design incorporates an elastic return spring with a plastically deformable segment that takes up wear play, featuring a C-shaped cross-section rail with complementary connection means for secure attachment to the fixed support and brake pad, ensuring proper alignment and deformation to manage the operating play.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rotating disc pushes back the brake pad to its inactive position, then the brake pad returns to its inactive position, but the brake pad does not return sufficiently far causing permanent rubbing and premature wear

Engineering Contradiction:

Improvebrake pad return functionVSAvoidpermanent rubbing and premature wear

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The elastic return spring is pre-loaded to exert a return force on the brake pad before the disc rotation begins to push it back. This preliminary elastic force ensures the brake pad is actively pushed back to the correct inactive position with sufficient clearance, preventing permanent rubbing and premature wear of the friction lining.

Inventive Principle:

Principle #10Preliminary action

2Power

If the brake pad is strongly clamped to the disc during braking, then braking performance is improved, but the disc does not have sufficient force to push the brake pad back causing residual torque

Engineering Contradiction:

Improvebraking performanceVSAvoidresidual torque and vehicle consumption

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The elastic return spring is pre-loaded to store elastic energy during the braking operation when the brake pad is clamped against the disc. This stored energy is then released to actively push the brake pad back to its inactive position, ensuring sufficient clearance and eliminating residual torque that would otherwise increase vehicle consumption.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The elastic return spring provides a dynamic, variable force during the brake pad return process. The spring force is maximum when the brake pad is in the active braking position and decreases as the brake pad returns to the inactive position, ensuring optimal force application throughout the return stroke to eliminate residual torque effectively.

Inventive Principle:

Principle #15Dynamics

3Reliability

If a plastically deformable segment is added to the spring to take up wear play, then wear compensation is improved, but the spring structure becomes more complex

Engineering Contradiction:

Improvewear play compensationVSAvoidspring structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The plastically deformable segment is integrated directly into the elastic return spring structure, merging the wear compensation function with the existing spring body. This integration eliminates the need for separate wear compensation mechanisms while maintaining the spring's primary elastic return function, thus improving reliability without significantly increasing overall structural complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Only a specific segment of the elastic return spring is made plastically deformable, while the rest of the spring maintains its elastic properties. This localized plastic deformation capability is strategically positioned to take up wear play, allowing the spring to adapt to friction lining wear while keeping the overall spring structure relatively simple and maintaining its primary elastic function.

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 effectively prevents premature wear of friction linings, maintains constant operating play, and reduces residual torque, enhancing vehicle performance and efficiency by ensuring proper brake pad alignment and return to the inactive position.

Implementation Method 1

at least one spring for elastically returning the brake pad to its inactive position

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

the spring including at least one plastically deformable segment, under the effect of an axial tensile strain, forming said means for taking up the wear play, this plastically deformable segment being shaped to be plastically elongated when the stroke of the brake pad up to its active position is higher than the determined operating play

Methodology Applied

Scientific EffectPlasticity: Plasticity

Data Source

PatentUS10746243B2Disc brake comprising at least one resilient return spring of a brake pad, resilient return spring, guiding slide and replacement kit

Publication Date: 2020.08.18 FOUND BRAKES FRANCE SAS

AI summary

Disclosed is a disc brake including a stationary support arm which includes a C-shaped recess, a slide which fits closely to the walls of the recess, a brake pad including two lateral lugs, each of which is received in a recess with a slide inserted therebetween, and a spring for resiliently returning the brake pad to its inoperative position, including a portion for attachment to the stationary support. The attachment portion includes an attachment tab, at least one flange of the slide includes an attachment strip, and the attachment tab and the attachment strip include complementary element for connection by form-fitting interaction.