Brake Fluid Recirculation for Thermal Management

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Solution Overview

Problem

High-performance road vehicle brakes often experience overheating during braking, leading to a loss of hydraulic braking power due to brake fluid temperature increases, which can be dangerous, and existing cooling solutions like air intakes worsen aerodynamics and are only needed infrequently.

Innovation Solution

A road vehicle braking system with a hydraulic circuit that includes delivery and return pipes for each front brake caliper, equipped with recirculation solenoid valves that allow for the circulation of brake fluid to replace hot fluid with cooler fluid from the hydraulic control unit, reducing brake fluid temperature without compromising aerodynamics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If air intakes are added to cool the brakes, then the brake cooling performance is improved, but the aerodynamic penetration coefficient deteriorates

Engineering Contradiction:
Improvebrake temperatureVSAvoidaerodynamic penetration coefficient
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical aerodynamic cooling system (air intakes and ducts) with a hydraulic circulation system. The hydraulic pump circulates brake fluid through cooling channels in the brake disc, using fluid dynamics instead of aerodynamic forces to achieve cooling, thereby eliminating the need for body air intakes and preserving aerodynamic performance

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

Solution Approach 2:

The invention uses a hydraulic circulation system where a pump moves brake fluid through cooling channels formed in the brake disc. This hydraulic approach replaces the aerodynamic cooling method, allowing heat transfer through the fluid medium without requiring external air flows that would compromise vehicle aerodynamics

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Temperature

If brake cooling ducts are installed, then the brake cooling capability is improved, but the manufacturing cost and complexity increase

Engineering Contradiction:
Improvebrake cooling capabilityVSAvoidmanufacturing cost and complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent merges the brake cooling function with the brake disc structure itself by forming cooling channels directly within the disc material. This integration eliminates the need for separate cooling ducts and air intake components, simplifying the overall system and reducing manufacturing steps while maintaining effective cooling capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The brake disc serves multiple functions: it provides the friction surface for braking and simultaneously acts as a heat exchanger through its internal cooling channels. This multi-functionality eliminates the need for dedicated cooling components, reducing system complexity and manufacturing requirements

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 effectively reduces brake fluid temperature by up to 20-30°C without additional ventilation, maintaining aerodynamic performance and simplifying manufacturing by eliminating the need for brake cooling ducts.

Implementation Method 1

a hydraulic pump (20) designed to pressurise the brake liquid in order to create a circulation of the brake liquid into each brake caliper (15) through a corresponding delivery pipe (22) and out of the brake caliper (15) through a corresponding return pipe (23)

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

During the braking phase, in the brakes of a road vehicle, the kinetic energy of the road vehicle is converted into heat, which is then disposed of in the external environment

Methodology Applied
Scientific EffectHeat Transfer: Conduction (thermal)

Data Source

PatentEP3309021B1Road vehicle braking system with forced recirculation of the brake liquid
Publication Date: 2021.05.05 FERRARI SPA
  • EP3309021B1 patent drawingFigure 1
  • EP3309021B1 patent drawingFigure 2
  • EP3309021B1 patent drawingFigure 3

AI summary

A braking system (12) for a road vehicle (1) having: a brake disc (14); a brake caliper (15) provided with at least one hydraulic piston (17); a hydraulic circuit (18) containing a brake liquid and having: a hydraulic control unit (19) provided with an electrically controlled pump (20) and a delivery pipe (22), which connects the hydraulic control unit (19) to the hydraulic piston (17); a return pipe (23), which is separate from and independent of the delivery pipe (22) and connects the hydraulic piston (17) to the hydraulic control unit (19); a recirculation solenoid valve (24), which is interposed along the return pipe (23) and can be controlled so as to enable or forbid the circulation of the brake liquid along the return pipe (23); and a control unit (21), which, when the braking system (12) is not used, opens the recirculation solenoid valve (24) and operates the electrically controlled pump (20) so as to create a circulation of the brake liquid through the first delivery pipe (22) and through the return pipe (23).