Brake Apparatus Controller Thermal Expansion Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional brake apparatuses fail to apply an appropriate braking force when restarted without a timer to measure the elapsed time period after ignition is turned off, leading to incorrect thermal expansion calculations and potential insufficient thrust force.
Innovation Solution
A brake apparatus with a controller that estimates the temperature of the frictional member and adjusts the thrust force of the pressing member holding mechanism to a corrected target thrust force by calculating a greater thrust force based on the temperature estimated value at the end of control, eliminating the need for a timer to measure elapsed time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a timer is used to measure the elapsed time period to calculate thermal expansion amount, then the braking force accuracy is improved, but the device complexity and power consumption increase
Solution Approach 1:
The patent extracts the timing measurement function from a dedicated timer component and integrates it into the controller's existing time-counting mechanism. The controller uses its internal clock to record the time period between ignition off and restart, eliminating the need for a separate timer hardware component while maintaining the ability to calculate thermal expansion accurately.
Solution Approach 2:
The controller is designed to perform multiple functions: it controls the electric motor, calculates thermal expansion amounts, and measures elapsed time using its internal time-counting mechanism. By making the controller universal and multi-functional, the patent eliminates the need for dedicated timer hardware, reducing device complexity while maintaining measurement precision.
2Use of energy by stationary object
If the timer is stopped when ignition is turned off to save power, then power consumption is reduced, but the thermal expansion calculation accuracy deteriorates
Solution Approach 1:
The controller performs preliminary action by recording the time period between ignition off and restart using its internal time-counting mechanism before the system fully shuts down. This pre-recorded time data is then used to calculate thermal expansion amount accurately upon restart, without requiring the timer to remain active during the off period, thus saving power while maintaining measurement precision.
Solution Approach 2:
The patent uses the controller's internal time-counting mechanism as a copy of the timer function. Instead of relying on a dedicated timer hardware that would need to remain powered, the controller replicates the timing measurement capability using its existing resources, allowing accurate elapsed time measurement without continuous power supply to a separate timer component.
3Speed
If the thrust force is set based on current temperature estimate, then the response speed is improved, but the braking force accuracy after restart deteriorates due to thermal contraction
Solution Approach 1:
The controller performs preliminary calculation of the thermal expansion amount at the time of ignition off using the temperature estimate at that moment. This pre-calculated thermal expansion data is stored and then used to determine the corrected target thrust force upon restart, compensating for thermal contraction that occurs during the off period. This allows fast response when braking is applied while ensuring accurate braking force after restart.
Solution Approach 2:
The system uses feedback by comparing the temperature estimate at ignition off with the current temperature estimate at restart. Based on this temperature change feedback, the controller calculates the thermal contraction amount and adjusts the target thrust force accordingly. This feedback mechanism ensures accurate braking force application after restart while maintaining fast response capability.
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
Ensures appropriate braking force application upon system restart, maintaining the vehicle in a stopped state by compensating for thermal contraction, without requiring a timer to measure elapsed time, thus preventing insufficient thrust force.
Implementation Method 1
a pressing member holding mechanism configured to thrust the pressing member by an electric motor
Implementation Method 2
a brake mechanism configured to thrust a frictional member disposed so as to be able to abut against each of rotational members
Implementation Method 3
reductions in temperatures of the disk rotor (the rotational member) and the brake pad (the frictional member) that were heated according to, for example, application of a braking force while the vehicle is running, thereby reducing thermal expansion amounts of the disk rotor and the brake pads
Data Source
AI summary
When a controller (19) is restarted after system control has ended, a brake apparatus drives an electric motor (43) so as to achieve a corrected target thrust force calculated by setting a greater thrust force than a target thrust force set according to a temperature estimated value of a frictional member at this time, based on the temperature estimated value of the frictional member at the time of the end of the control, or drives the electric motor based on the temperature estimated value of the frictional member at the time of the end of the control.