Disc Brake Clearance Control for Fast Response and Low Residual Torque

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Solution Overview

Problem

Existing brake-by-wire disc braking systems lack the ability to dynamically adjust the distance between the brake disc and pads in real-time, which limits the optimization of braking action and reduction of residual torque under varying vehicle conditions.

Innovation Solution

A braking system equipped with an electric actuator and a processing and control unit that implements an algorithm to dynamically adjust the gap between the brake disc and pads based on various dynamic vehicle parameters, such as collision time, road friction coefficient, and traffic conditions, to anticipate and respond to potential braking demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a large clearance is maintained between the brake disc and pads, then residual braking torque and pad wear are reduced, but brake response time increases due to the delay in initiating braking action

Engineering Contradiction:
Improveresidual braking torque and pad wearVSAvoidbrake response time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent applies the dynamics principle by enabling the clearance between the brake disc and pads to be dynamically adjusted in real-time based on driving conditions. The control unit modifies the gap distance according to parameters such as vehicle speed, deceleration rate, and brake usage patterns, allowing the system to optimize between minimal residual torque and rapid response time as conditions change

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by varying the physical dimension of the clearance gap between the brake disc and pads. The control unit adjusts this geometric parameter electronically, changing it from a fixed design value to a variable parameter that can be optimized for different operating conditions, thereby resolving the contradiction between minimizing residual torque and maximizing response speed

Inventive Principle:
Principle #35Parameter changes

2Speed

If a small distance is maintained between the brake disc and pads, then braking readiness is improved by reducing delay, but residual braking torque increases along with pad wear and fuel consumption

Engineering Contradiction:
Improvebraking readinessVSAvoidresidual braking torque, pad wear, and fuel consumption
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts the pad-to-disc clearance based on real-time driving conditions. During normal cruising, the clearance is maximized to minimize residual torque and wear. When braking is anticipated or required, the control unit reduces the clearance to ensure rapid response, thus dynamically optimizing both braking readiness and minimizing harmful effects

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control unit performs preliminary action by anticipating braking demands based on driving patterns and proactively adjusting the clearance to optimal values before braking is actually required. This prepares the braking system in advance, ensuring rapid response when needed while maintaining minimal residual torque during normal operation

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If the piston position is fixed at design stage, then manufacturing simplicity is maintained, but the system cannot adapt to varying vehicle conditions in real-time

Engineering Contradiction:
Improvefixed piston positionVSAvoidreal-time adjustment capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent replaces the traditional mechanical fixed-position piston system with an electro-mechanical actuator system controlled by electronic signals. The control unit receives input from various sensors and algorithms, then electronically commands the actuator to adjust piston position, substituting complex mechanical adjustment mechanisms with controllable electro-mechanical components that achieve adaptability while maintaining manufacturing feasibility

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control unit serves multiple functions: it monitors driving conditions, predicts braking demands, calculates optimal clearance values, and commands actuator adjustments. This multi-functional control system enables the braking system to adapt to various vehicle conditions while using a standardized actuator component, achieving versatility without proportionally increasing device complexity

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

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 system enhances braking responsiveness and reduces residual torque by dynamically adjusting the gap, thereby improving driving safety, reducing pad wear, and increasing vehicle range while minimizing emissions.

Implementation Method 1

at least one electric actuator, operatively connected to a piston acting as a pusher on at least one of said pads along said actuation direction

Methodology Applied
Scientific EffectElectromechanical conversion: Linear Motor

Implementation Method 2

said disc brake caliper at said pad comprises thrust means such as springs or spiders which exert an elastic action of axially distancing the pad from the brake disc

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4341137B1Disc brake equipped with dynamic adjustment of the clearance between the brake disc and the pads and related method
Publication Date: 2025.04.30 FRENI BREMBO SPA
  • EP4341137B1 patent drawingFigure 1

AI summary

A braking system (4) for a vehicle (8) comprising at least one disc brake (12) comprising a disc brake (16) having a disc brake caliper (20) and at least one pair of pads (24) on sides opposite each other along an axial direction of actuation (A-A), at least one electric actuator (32) operatively connected to a piston (36) acting as a pusher on at least one of said pads (24), a processing and control unit (40), operatively connected to said electric actuator (32), and programmed so as to move the piston (36) and the respective pad (24), along the axial direction of actuation (A-A) to a forward position so as to press the pad (24) into contact with the brake disc (16) during a braking demand and so as to bring the piston (36) and its pad (24) to a rest or rearward position, wherein a gap (44) is identified between the pad (24) and the brake disc (16), wherein the processing and control unit (40) is programmed to implement an algorithm that, in the absence of a braking demand, operates the electric actuator (32) by varying said gap (44) according to at least one dynamic parameter of the vehicle (8) that defines the prediction of a future demand for braking action.