Inductive Axle Load Sensor in Brake Valve Housing

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Solution Overview

Problem

Existing sensors for detecting axle loads in commercial vehicles are susceptible to faults and damage due to their design and arrangement, making them unreliable for accurately recording and transmitting axle load data to drivers and control points.

Innovation Solution

A load-dependent brake valve with an inductively designed sensor, such as an inductive angle or displacement sensor, is integrated within the brake valve housing, allowing for precise detection of the axle load's deflection path relative to the vehicle frame and conversion into an electronic signal, providing a secure and reliable measurement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure sensors are connected to the bellows of air springs or arranged on them, then axle loads can be recorded, but the sensors are susceptible to faults and easily damaged

Engineering Contradiction:

Improvesensor reliabilityVSAvoidsensor damage risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary mechanical linkage system that transmits the bellows expansion/contraction motion to the sensor without exposing the sensor to the harsh environment. The sensor remains in the protected brake valve housing while still detecting the axle load through the mechanical transmission of motion.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct mechanical contact sensors with an inductive sensor that detects position through magnetic field changes. This eliminates mechanical wear and contact-based failure modes, significantly improving sensor reliability while maintaining the ability to measure axle load.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If strain gauges are arranged on mechanical spring elements or tire pressure sensors in tires, then axle loads can be detected, but the sensors are relatively susceptible to faults due to their design and arrangement

Engineering Contradiction:

Improveaxle load detection accuracyVSAvoidsensor fault susceptibility

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent uses a mechanical linkage as an intermediary to transmit the spring element deformation to the sensor. This allows the sensor to remain in a protected environment while still accurately measuring the axle load through the transmitted mechanical motion.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces strain gauges that directly contact mechanical spring elements with an inductive sensor that measures position through magnetic field changes. This substitution eliminates the susceptibility to faults associated with direct mechanical contact while maintaining measurement precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If sensors are arranged externally to detect axle load deflection, then axle loads can be recorded, but the sensors are easily damaged due to their arrangement

Engineering Contradiction:

Improveaxle load recording capabilityVSAvoidsensor damage from arrangement

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent merges the sensor into the brake valve housing, combining two separate functions (brake control and axle load measurement) into a single integrated unit. This eliminates the need for separate external sensor mounting and protects the sensor within the existing valve housing structure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a mechanical linkage system as an intermediary to connect the axle load deflection measurement to the sensor inside the brake valve housing. This allows the sensor to remain protected while still capturing the necessary measurement data.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enables reliable and precise recording of axle loads, protecting the sensor from damage and reducing assembly complexity, while allowing for real-time display to drivers and transmission to control points, thus addressing the reliability issues of existing sensors.

Implementation Method 1

The sensor is preferably designed as an inductive sensor. According to a first embodiment of the sensor, this is designed as an inductive angle of rotation sensor

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3448729B1Device for electronic sensing of the axle load of a motor vehicle

Publication Date: 2020.07.01 ZF CV SYST EURO BV

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AI summary

The invention relates to a load-dependent brake valve (5.1; 5.2) designed to supply brake pressure dependent on an axle load of a vehicle (1). According to the invention, this brake valve (5.1; 5.2) has a sensor (11.1; 11.2) for electronically sensing an axle load of the vehicle (1). The sensor (11.1; 11.2) is preferably an inductive sensor (11), which can be in the form of a rotation angle sensor (11.1) or a displacement sensor (11.2).