Brake Booster Diaphragm Pressure Control via Vacuum Pump

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Solution Overview

Problem

Existing brake booster systems fail to maintain a consistent pressure differential across the diaphragm at all engine operating conditions or altitudes, as pressurized air from the turbocharger may not be available and ambient air pressure varies with altitude.

Innovation Solution

An electrically driven vacuum pump is used to apply both vacuum and positively-pressurized air to respective chambers of the brake booster system, with a controller managing the operation to ensure a consistent pressure differential by coupling the vacuum pump's exhaust to the working chamber and inlet to the vacuum chamber, and using manifold pressure when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressurized air from the turbocharger is applied to the brake booster working chamber, then brake booster assistance is provided, but the pressure differential cannot be maintained when turbocharger air is unavailable

Engineering Contradiction:

Improvebrake booster performance consistencyVSAvoidadaptability to different engine operating conditions

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The vacuum pump serves multiple functions: it generates vacuum for the vacuum chamber and simultaneously provides pressurized air to the working chamber through its exhaust outlet. This multi-functionality ensures brake booster operation across all engine conditions without relying on turbocharger availability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The vacuum pump acts as an intermediary device that decouples the brake booster system from direct dependence on turbocharger operation. By introducing this intermediate vacuum pump system, the patent ensures consistent pressure differential maintenance regardless of engine operating conditions or altitude.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the brake booster is coupled to the engine air intake manifold for vacuum supply, then vacuum is available for the vacuum chamber, but ambient air pressure variations with altitude affect performance

Engineering Contradiction:

Improvevacuum supply reliabilityVSAvoidaltitude adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The vacuum pump serves as an intermediary that generates vacuum independently of ambient air pressure conditions. By actively pumping to create vacuum in the vacuum chamber rather than relying on atmospheric pressure differences, the system maintains consistent performance across varying altitudes.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the passive atmospheric pressure-based vacuum system with an active vacuum pump system. This substitution transforms the vacuum generation mechanism from one dependent on ambient conditions to one that actively maintains desired pressure levels regardless of external environment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If a single vacuum source is used for both chambers, then system complexity is reduced, but the desired pressure differential cannot be maintained across all operating conditions

Engineering Contradiction:

Improvevacuum system complexityVSAvoidpressure differential maintenance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent segments the pressure control system by providing separate pressure sources for the working chamber and vacuum chamber. The vacuum pump's inlet connects to the vacuum chamber while its exhaust connects to the working chamber, allowing independent pressure management in each chamber to maintain the required pressure differential.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically manages pressure in each chamber independently through the vacuum pump's dual connections. By controlling the vacuum pump operation and utilizing the pressure differences between inlet and exhaust, the system adaptively maintains the optimal pressure differential across varying operating conditions.

Inventive Principle:

Principle #15Dynamics

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 maintains a desired pressure differential across the diaphragm regardless of engine operating conditions or altitude, ensuring consistent brake booster performance.

Implementation Method 1

applying a vacuum pressure from the vacuum pump to vacuum chamber

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

maintain a consistent pressure differential across the diaphragm

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS9663090B2Brake booster assistance

Publication Date: 2017.05.30 FORD GLOBAL TECH LLC

AI summary

Systems and methods for a vehicle brake booster having first and second chambers separated by a diaphragm coupled to a brake pedal are provided. In one example approach, a method comprises applying an exhaust pressure from a vacuum pump to a first chamber of the brake booster, and applying a vacuum pressure from the vacuum pump to a second chamber of the brake booster.