Electromechanical Brake Device with Three Control Units

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Solution Overview

Problem

Existing electric brake systems require additional mechanical brakes for backup, increasing vehicle cost and complexity, and lack efficient control mechanisms for four-wheel braking with three or fewer control units.

Innovation Solution

The electric brake device uses three control units to manage four brake mechanisms, dynamically balancing braking forces across wheels in case of failures, and integrates parking brake functions into rear wheel mechanisms to reduce parts and weight, with dual batteries for redundancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical brake is provided in addition to an electrically controlled brake system for backup braking, then braking reliability is improved, but device complexity and vehicle cost increase

Engineering Contradiction:
Improvebraking reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the traditional mechanical backup brake system with an electrically controlled brake system that can operate independently. The electric brake mechanism uses an electric actuator to apply braking force through a friction-applying member pressing against a friction-receiving member, eliminating the need for a separate mechanical brake system while maintaining backup braking capability.

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

Solution Approach 2:

The electric brake mechanism is designed to serve multiple functions: it acts as the primary braking system under normal operation and simultaneously serves as the backup braking system when the electrically controlled brake system fails. This multi-functionality is achieved through the redundant control unit architecture and the ability of the electric actuator to provide braking force independently.

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

2Reliability

If four control units are provided for four wheel braking mechanisms, then braking control reliability is improved, but device complexity and vehicle cost increase

Engineering Contradiction:
Improvebraking control reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the control functions for the left and right wheel braking mechanisms into a single control unit. The third control unit is configured to control both the third brake mechanism (left wheel) and the fourth brake mechanism (right wheel), reducing the total number of control units from four to three while maintaining the ability to independently control each wheel's braking force.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control system is segmented into three independent control units, where the first control unit controls the first brake mechanism, the second control unit controls the second brake mechanism, and the third control unit controls both the third and fourth brake mechanisms. This segmentation allows for reduced complexity while maintaining redundancy and independent control capabilities.

Inventive Principle:
Principle #1Segmentation

3Productivity

If brake mechanisms are provided for all four wheels, then braking performance is improved, but vehicle weight and cost increase

Engineering Contradiction:
Improvebraking performanceVSAvoidvehicle weight
Core Design Contradiction:
ProductivityVSWeight of moving object

Solution Approach 1:

The rear wheel brake mechanisms serve dual functions: they act as service brakes during normal braking operation and as parking brake mechanisms when parking is required. This multi-functionality eliminates the need for separate parking brake mechanisms, reducing vehicle weight and component count while maintaining full braking and parking capabilities.

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

This configuration reduces vehicle cost and weight, enhances braking force balance and stability, and improves responsiveness by using electric actuators to press brake pads against rotating disks, maintaining effective braking even with control unit failures.

Implementation Method 1

a friction-applying member that moves while being powered by an electric actuator

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

obtains the braking force by pressing the friction-applying member against the friction-receiving member

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3318457B1Electromechanical brake device
Publication Date: 2021.09.22 MITSUBISHI MOTORS CORP
  • EP3318457B1 patent drawingFigure 1
  • EP3318457B1 patent drawingFigure 2A~2C
  • EP3318457B1 patent drawingFigure 3A~4B

AI summary

An electric brake device (10) has at least three control units: a front-left wheel control unit (28) for controlling a front-left wheel brake mechanism (20), a front-right wheel control unit (30) for controlling a front-right wheel brake mechanism (22), and a rear-left/right wheel control unit (32) for controlling a rear-left wheel brake mechanism (24) and a rear-right wheel brake mechanism (26). Each of the brake mechanisms (20), (22), (24) and (26) has a friction-receiving member that rotates together with the wheel, and a friction-applying member that moves while being powered by an electric actuator, and generates the braking force by pressing the friction-applying member against the friction-receiving member.