Hydraulic Brake Booster Eliminates Accumulator

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Solution Overview

Problem

Conventional brake devices with hydraulic booster stages are complex, rely on heavy and expensive high-pressure accumulators, and have suboptimal response characteristics, making them unsuitable for modern automated driving systems and space-constrained vehicles.

Innovation Solution

A brake device with a compact, energy-efficient hydraulic booster stage directly fed by a motor pump unit, eliminating the need for external high-pressure accumulators, and featuring modular design, sensor monitoring, and adjustable response characteristics through an elastic reaction disc and transmission piece, allowing for seamless integration with existing systems and vacuum brake boosters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional vacuum brake boosters are used, then pedal feel and response characteristics are comfortable, but the device becomes large and reaches technical limits for automated driving systems

Engineering Contradiction:
Improvepedal feel and response characteristicsVSAvoidspace available
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The patent replaces the vacuum-based mechanical booster system with a hydraulic booster stage that is electrically actuated. The hydraulic booster uses a motor-driven pump to generate hydraulic pressure, eliminating the need for a vacuum pump and reservoir, thereby reducing overall system size while maintaining actuation effectiveness for automated driving applications.

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

Solution Approach 2:

The hydraulic booster stage is designed to serve multiple functions: it provides brake actuation for normal driving, supports automated emergency braking functions, and can be integrated with existing master brake cylinders. This multi-functionality allows a single compact unit to replace both the vacuum booster and accommodate automated driving requirements.

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

2Area of stationary object

If compact hydraulic booster stages are used, then space is reduced, but the device becomes complex and requires heavy high-pressure accumulators

Engineering Contradiction:
Improveinstallation spaceVSAvoidsystem complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the high-pressure accumulator from the hydraulic system. Instead of using a separate accumulator component to store hydraulic pressure, the system uses a motor-driven pump that can rapidly generate pressure on demand, thereby simplifying the overall system architecture while maintaining compact dimensions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The motor-driven pump is designed to pre-charge the hydraulic circuit to a moderate pressure level during normal operation, so that when braking is required, the pump can quickly build up the necessary high pressure without needing a large accumulator. This preliminary action reduces the need for heavy pressure storage components.

Inventive Principle:
Principle #10Preliminary action

3Area of stationary object

If compact hydraulic booster stages are used, then space is reduced, but response characteristics are in need of improvement

Engineering Contradiction:
Improveinstallation spaceVSAvoidresponse characteristics
Core Design Contradiction:
Area of stationary objectVSSpeed

Solution Approach 1:

The system employs a motor-driven pump with variable speed control that can dynamically adjust its operation based on braking demands. During normal driving, the pump operates at lower speeds to maintain system pressure. During emergency braking, the pump can rapidly increase its speed to build pressure quickly, thereby improving response characteristics without requiring a larger physical system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters of the hydraulic system by using a motor-driven pump that can rapidly vary pressure and flow rate. This allows the system to maintain compact dimensions while achieving fast response times by dynamically adjusting pressure buildup rate based on the braking situation, rather than relying on fixed-pressure accumulators.

Inventive Principle:
Principle #35Parameter changes

4Stress or pressure

If hydraulic booster stages with high-pressure accumulators are used, then pressure is available, but weight and cost increase

Engineering Contradiction:
Improvehydraulic pressureVSAvoidweight
Core Design Contradiction:
Stress or pressureVSWeight of moving object

Solution Approach 1:

The patent replaces the mechanical high-pressure accumulator with an electrically driven hydraulic pump system. The motor-driven pump generates hydraulic pressure on demand through electrical power, eliminating the need for heavy metal accumulators while maintaining the necessary pressure levels for effective brake actuation.

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

Solution Approach 2:

The system changes from a static high-pressure storage approach to a dynamic pressure generation approach. The motor-driven pump can rapidly generate the required hydraulic pressure when needed, allowing the system to use lighter components while maintaining adequate pressure for braking functions.

Inventive Principle:
Principle #35Parameter changes

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 reduces component count, installation space, weight, and costs while enabling comfortable pedal feedback and adjustable response characteristics, facilitating fully automated braking and integration with automated driving systems.

Implementation Method 1

After activation, the motor pump unit conveys the pressure medium from the pressure medium tank into the pressure chamber (5) and causes a pressure build-up therein

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

The use of an elastic reaction disc between the piston rod and the pressure piston ensures haptically comfortable feedback on the brake pedal

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3380374B1Brake device for hydraulic brake system
Publication Date: 2020.08.12 CONTINENTAL TEVES AG & CO OHG
  • EP3380374B1 patent drawingFigure 1~2
  • EP3380374B1 patent drawingFigure 3
  • EP3380374B1 patent drawingFigure 4

AI summary

The invention relates to an improved modular braking device (1) for a hydraulic motor vehicle brake system, which is optimized for remote actuation, comprising a hydraulic booster stage (2) with a booster housing (3), a main brake cylinder (7) mounted thereon, a booster piston (4) which is displaceable therein and delimits a pressure chamber (5) which is supplied directly with pressure medium by a motor pump unit (10).