Electric Drum Brake Clearance Control for Thermal Drag
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing brake apparatuses, particularly electric drum brakes, experience brake drag due to thermal deformation, where the clamping force increases as the temperature drops, leading to inadequate reduction of engagement force when the brake is disengaged.
Innovation Solution
A brake apparatus and control method that estimate the temperature of the rotating member (drum) and adjust the distance between the friction member (brake lining) and the rotating member based on the estimated temperature to prevent brake drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the brake is disengaged before the temperature has dropped sufficiently, then the brake release time is reduced, but the clamping force cannot be reduced sufficiently causing brake drag
Solution Approach 1:
The controller estimates the temperature of the rotating member before fully disengaging the brake and uses this information to determine the appropriate timing for brake release. By performing the temperature estimation action in advance, the system can predict when the clamping force will be sufficient to prevent brake drag, thus resolving the contradiction between quick brake release and adequate force reduction.
2Device complexity
If the distance between the friction member and the rotating member is not adjusted based on temperature, then the device complexity is reduced, but brake drag occurs due to thermal deformation
Solution Approach 1:
The controller continuously estimates the temperature of the rotating member and uses this feedback information to dynamically adjust the distance between the friction member and the rotating member. This closed-loop control system monitors temperature changes and automatically compensates for thermal deformation, preventing brake drag without requiring complex mechanical adjustment mechanisms.
Solution Approach 2:
Instead of using complex mechanical mechanisms to physically adjust the brake clearance based on temperature, the patent employs an electronic control system that calculates the optimal distance and controls the motor accordingly. This substitution of mechanical adjustment with electronic control simplifies the overall device complexity while effectively addressing thermal deformation issues.
3Stability of the object's composition
If the friction member position is adjusted based on estimated temperature, then the braking performance stability is improved, but the measurement precision requirement increases
Solution Approach 1:
The controller adjusts the distance between the friction member and rotating member based on changes in temperature parameters. By monitoring temperature variations and dynamically changing the clearance parameter, the system maintains stable braking performance across different thermal conditions. The controller uses temperature change trends rather than absolute precision to determine adjustment timing.
Solution Approach 2:
The system applies a predetermined reference distance plus an additional distance when temperature is high, rather than making precisely minimal adjustments. This excessive action approach ensures that even with limited temperature estimation precision, the brake clearance is sufficient to prevent drag while the motor gradually reduces the distance as temperature decreases, achieving stable performance without requiring high measurement precision.
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 effectively prevents brake drag by accurately adjusting the distance between the friction member and the rotating member based on the estimated temperature, thereby ensuring stable braking performance.
Implementation Method 1
a motor that moves the friction member
Implementation Method 2
a friction member that applies a frictional force to the rotating member
Implementation Method 3
a phenomenon in which the clamping force increases due to thermal deformation, i.e., contraction of the drum
Data Source
AI summary
Disclosed herein is a brake apparatus that may include a rotating member, a friction member that applies a frictional force to the rotating member, a motor that moves the friction member, and a controller that controls operation of the motor. The controller may determine a reference position based on a position of the friction member at a time point at which the friction member is no more in contact with the rotating member when the brake is released and control movement of the friction member from the reference position to adjust a distance between the friction member and the rotating member based on an estimated temperature of the rotating member when the brake is released.