Master Cylinder Position Sensor Integration for Brake Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing master cylinder assemblies for automotive braking systems face reliability issues in detecting brake pedal actuation due to the use of additional displaceable position transmitter elements and electrically operated detection units, which increases the risk of malfunctions.

Innovation Solution

A master brake cylinder arrangement that includes a displaceable piston, a force input member coupled to the piston, an elongate locator element, and a detection unit with a magnetic field sensor, where the position transmitter element is designed to interact with the detection unit, allowing for reliable detection of brake pedal actuation without additional displaceable elements and reducing the risk of malfunctions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional displaceable position transmitter elements and electrically operated detection units are provided, then brake pedal actuation detection capability is improved, but the risk of malfunctions increases

Engineering Contradiction:
Improvebrake pedal actuation detectionVSAvoidsystem malfunction risk
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts the position transmitter function from separate displaceable elements and integrates it directly into the piston structure. The piston itself serves as the position transmitter, eliminating the need for additional displaceable position transmitter elements and reducing system complexity while maintaining detection accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The piston is designed to serve multiple functions simultaneously: it acts as both the hydraulic actuator for brake pressure generation and the position transmitter for detection. This multi-functionality reduces the number of separate components needed, thereby reducing malfunction risk while maintaining detection capability.

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

2Reliability

If a non-contact Hall effect position sensor is used, then detection reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsensor integration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The detection unit is integrated directly into the master cylinder housing, merging the detection function with the existing structural components. This integration approach reduces device complexity by eliminating separate mounting structures and connection elements while maintaining non-contact detection reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses the piston's magnetic properties as an intermediary between the physical displacement and the Hall effect sensor detection. The magnetic field generated by the piston serves as a mediator that enables non-contact position detection without requiring direct mechanical connection or complex sensor mounting.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Volume of moving object

If the detection unit is integrated into the master cylinder, then system compactness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvemaster cylinder assembly volumeVSAvoidassembly manufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The master cylinder is divided into functional modules: the housing integrated with the detection unit, the piston assembly with magnetic properties, and the sealing components. This segmentation allows each module to be manufactured separately using optimized processes and then assembled, reducing overall manufacturing complexity while achieving compact integration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs injection molding techniques with modified material parameters to integrate the detection unit housing directly into the master cylinder body. By changing the manufacturing parameters (using thermoplastic materials with magnetic properties or embedding sensors during molding), the complex integrated structure can be produced in a single manufacturing step rather than through multiple assembly operations.

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

The solution provides a more reliable detection of brake pedal actuation, reducing the risk of malfunctions and ensuring accurate braking force application in both driver-decoupled and hydraulic brake systems.

Implementation Method 1

a detection unit that is designed to detect a displacement of the position transmitter element

Methodology Applied
Scientific EffectMagnetic field sensor detection: Magnetic Field

Data Source

PatentEP3551512B1Master cylinder arrangement with position sensor and sealing arrangement
Publication Date: 2020.11.11 ZF ACTIVE SAFETY GMBH
  • EP3551512B1 patent drawingFigure 1
  • EP3551512B1 patent drawingFigure 2
  • EP3551512B1 patent drawingFigure 3

AI summary

The invention relates to a main brake cylinder arrangement (10) for a motor vehicle brake system, comprising: at least one piston (44), which can be displaced along a displacement axis (V) and, together with a housing arrangement (12), delimits a pressure chamber; a force input member (19), which is displaceable according to a brake pedal actuation and is coupled or can be coupled to the piston (44) for common displacement; an elongated position encoder element (60), which is displaceable according to an actuation of the force input member (18); a detection unit (66), which is designed to detect a displacement of the position encoder element (60); and a receiving region (64), which is designed to receive the position encoder element (60) at least in sections. According to the invention, the ends (62, 68) of the position encoder element (60) are each arranged in a different housing region (F, S), which is arranged in a fluid path between the first and second housing region (F, S).