Spring Brake Actuator Sensor Restraint for Accurate Stroke Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spring brake actuators in vehicle braking systems exhibit non-linear output force throughout their range of motion, decreasing near the full-stroke limit, which can lead to brake adjustment violations and safety concerns.
Innovation Solution
The development of a spring brake actuator with a sensor assembly housed in the actuator's chamber, featuring a stiffening element and a radially extending leg that engages the stiffening element to limit excessive rotation and translation of the sensor assembly, thereby enhancing its accuracy and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor assembly is allowed to move freely in the chamber, then the sensor can detect the full range of push rod positions, but the sensor assembly may experience excessive movement and rotation leading to measurement errors and potential damage
Solution Approach 1:
The sensor assembly is segmented from the push rod and chamber components, allowing independent optimization of each part. The sensor assembly can be positioned and constrained separately to achieve both measurement accuracy and durability without compromising the overall brake actuator functionality.
Solution Approach 2:
The sensor assembly is pre-positioned within the chamber at optimal locations for detecting push rod position throughout its full stroke range. This preliminary positioning ensures accurate measurement while the housing and stiffening elements prevent excessive movement before operation begins.
2Reliability
If the sensor assembly is constrained by the housing, then excessive movement and rotation are prevented, but the sensor assembly may be limited in its ability to detect the full range of push rod positions
Solution Approach 1:
The housing provides localized constraint through stiffening elements at specific locations within the chamber, rather than complete restriction. This allows the sensor assembly to move sufficiently for accurate detection while being constrained enough to prevent excessive movement and rotation that would cause damage or measurement errors.
3Productivity
If the push rod extends fully out of the chamber, then the brake is fully activated, but the output force decreases near the full-stroke limit reducing braking effectiveness
Solution Approach 1:
The sensor assembly provides real-time feedback on push rod position throughout the stroke range, enabling the control system to identify when the push rod approaches the full-stroke limit where force output decreases. This feedback allows for compensatory control actions to maintain effective braking force.
Data Source
AI summary
A spring brake actuator for braking a wheel of a vehicle includes a housing defining a chamber, a push rod extending from the chamber such that pneumatic activation of the spring brake actuator causes the push rod to further extend out of the chamber to thereby activate braking of the wheel of the vehicle and such that pneumatic deactivation of the spring brake actuator causes the push rod to retract back into the chamber to thereby deactivate braking of the wheel of the vehicle, and a sensor assembly located in the chamber such that the housing limits movement of the sensor assembly in the chamber.