Electric Hydraulic Brake Layout With Redundant Auxiliary Flow Path

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Solution Overview

Problem

Existing electric hydraulic brake systems face challenges with increased complexity, cost, and weight due to the addition of auxiliary brake systems for redundancy, which complicates the brake system layout and increases overall cost and weight.

Innovation Solution

The electric hydraulic brake integrates a main braking unit and a hydraulic controller within a one-box configuration, reducing the number of components and simplifying the brake piping layout, while ensuring redundancy through an auxiliary flow path that directly connects the reservoir to the pump, bypassing the master cylinder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an auxiliary brake system is added to the main brake system to implement redundancy, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvebrake system redundancyVSAvoidbrake system layout
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the main brake system and auxiliary brake system into a single integrated brake unit. The main brake motor and auxiliary brake motor share a common master cylinder, reservoir, and control electronics. This merging approach maintains redundancy functionality while significantly simplifying the overall system layout and reducing the number of separate components compared to traditional dual-brake-system architectures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The master cylinder is designed to serve dual purposes: it functions as the primary pressure generation device for normal braking operations and simultaneously serves as the auxiliary brake mechanism when the main brake motor fails. The reservoir also serves multiple functions by supplying brake fluid to both the main brake motor and auxiliary brake motor. This multi-functionality reduces the need for separate dedicated components for each brake system.

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

2Reliability

If an auxiliary brake system is added to the main brake system to implement redundancy, then reliability is improved, but weight increases

Engineering Contradiction:
Improvebrake system redundancyVSAvoidbrake system weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent merges the auxiliary brake components with the main brake system, sharing the master cylinder, reservoir, brake lines, and control electronics. This sharing of common components significantly reduces the additional weight that would result from completely separate auxiliary brake systems, while still providing the necessary redundancy for fail-safe operation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The master cylinder and reservoir are designed as multi-functional components that serve both the main brake motor and auxiliary brake motor. By having these components perform dual roles, the patent avoids the need for separate dedicated components for the auxiliary system, thereby reducing overall brake system weight while maintaining redundancy capabilities.

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

3Reliability

If an auxiliary brake system is added to the main brake system to implement redundancy, then reliability is improved, but cost increases

Engineering Contradiction:
Improvebrake system redundancyVSAvoidbrake system cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent integrates the auxiliary brake system with the main brake system by sharing common components including the master cylinder, reservoir, brake fluid lines, and control electronics. This consolidation reduces the total number of parts that need to be manufactured, sourced, and assembled, thereby lowering overall system cost compared to implementing completely separate auxiliary and main brake systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The master cylinder and reservoir are designed as universal components that serve both normal braking operations and auxiliary braking operations. This multi-functionality eliminates the need to manufacture and install separate dedicated components for the auxiliary system, reducing material costs, manufacturing complexity, and assembly costs while still providing the required redundancy for fail-safe operation.

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 enhances cost competitiveness and maintains required performance by simplifying the brake system, reducing components, and ensuring effective braking force application even in malfunction scenarios, such as during autonomous driving.

Implementation Method 1

a pump configured to pump the brake oil in conjunction with an auxiliary brake motor

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

a master cylinder configured to form pressure of the brake oil in conjunction with a main brake motor

Methodology Applied
Scientific EffectHydraulic pressure generation: Hydraulic Press

Implementation Method 3

a plurality of wheel brakes supplying braking force to wheels of a vehicle

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4119407B1Electric hydraulic brake and control method therefor
Publication Date: 2026.04.01 HYUNDAI MOBIS CO LTD
  • EP4119407B1 patent drawingFigure 1
  • EP4119407B1 patent drawingFigure 2
  • EP4119407B1 patent drawingFigure 3

AI summary

An electric hydraulic brake (1) includes: wheel brakes (w1, w2, w3, w4) configured to supply braking force to wheels of a vehicle; a main braking unit (100) including a reservoir (110) which stores brake oil, and a master cylinder (120) configured to form pressure of the brake oil in conjunction with a main brake motor (122); and a hydraulic controller (200) comprising at least one pump (231) configured to pump the brake oil in conjunction with an auxiliary brake motor (230), and configured to selectively transmit the pressure of the brake oil formed in the master cylinder (120) or the pump (231) to the wheel brakes (w1, w2, w3, w4). The hydraulic controller (200) includes at least one auxiliary flow path (221, 222) which is connected at a first end thereof to the reservoir (110) and is connected at a second end thereof to an inlet of the pump (231) to transmit hydraulic pressure from the reservoir to the pump (231) directly through the at least one auxiliary flow path (221, 222).