Drum Brake Abutment Deformation Sensing for Precise Force Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drum brake systems with electric actuators lack precise control due to insufficient measurement of total forces acting on the brake shoes, as friction forces vary, leading to inaccurate support force readings.
Innovation Solution
An elastically configured abutment with integrated sensors that detect deformation under load, allowing for precise measurement of forces and brake moments by using strain gauges, Hall sensors, or AMR sensors to determine mechanical stresses or changes in limb positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a load sensor is arranged on the abutment to measure support force, then force measurement capability is provided, but measurement precision is insufficient because friction forces vary between brake shoes
Solution Approach 1:
The measurement system is segmented into multiple independent load sensors, with each sensor dedicated to measuring the support force of a specific brake shoe. This segmentation allows each sensor to capture local force conditions accurately, and the control unit can then process individual measurements from each sensor to determine total forces and brake moments, resolving the precision issue caused by varying friction forces between shoes.
Solution Approach 2:
The load sensors serve multiple functions: they measure support forces for control regulation, provide data for calculating total forces, enable determination of brake moments, and support monitoring of individual brake shoe conditions. This multi-functionality allows a single measurement component to address multiple control requirements simultaneously.
2Measurement precision
If individual load sensors are used for each brake shoe, then measurement capability is provided, but device complexity increases
Solution Approach 1:
Multiple load sensors are merged into a unified measurement system where individual sensor measurements are combined by the control unit to calculate total forces and brake moments. This merging approach maintains high measurement accuracy while managing system complexity through integrated data processing rather than physically separate measurement systems.
Solution Approach 2:
The control unit performs multiple functions: it receives signals from individual load sensors, processes each measurement, calculates total forces, determines brake moments, and regulates the actuator. This multi-functional control unit reduces overall system complexity by consolidating processing tasks rather than requiring separate systems for each function.
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
Enables precise control of the actuator by accurately measuring forces and brake moments, reducing the risk of excessive force application and improving brake performance under varying conditions, such as temperature changes, by providing automatic force compensation and enhanced parking brake functionality.
Implementation Method 1
an abutment 5, wherein the abutment 5 as a whole is configured as a solid component which can yield elastically under load
Implementation Method 2
strain gauges at the anvil. In this embodiment, the deformation of the abutment is thus determined indirectly via mechanical stresses in the abutment
Implementation Method 3
Another possibility is that the sensor or sensors detect the distance between the free ends of the limbs. This may be take place for example using Hall sensors
Implementation Method 4
AMR sensors based on the anisotropic magneto-resistive effect, for which the limbs are provided with magnets which function as signal emitters for the Hall sensor or AMR sensor
Data Source
AI summary
The abutment of a drum brake is formed from a solid material which deforms under load, wherein measurement devices are provided which detect this deformation. The abutment has two limbs, on which the brake shoes are supported. The changing distance between the two brake shoes under load is determined by detecting the distance between extension rods on the limbs by a measurement device comprising magnets and Hall sensors or AMR sensors.