Electric Disk Brake Pad Retraction Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric disk brakes experience uneven abrasion of the disk rotor due to thermal deformation, leading to irregular contact between the rotor and brake pads, which causes brake judder and uneven wear.
Innovation Solution
An electric disk brake system that includes a controller to maintain the pad pressing member in position after the brake is disengaged, using a pad-retracting-control electric current to ensure brake pad retraction when the disk rotor contacts the pads and maintaining position when it does not, thereby preventing further contact and abrasion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the electric motor is controlled to maintain constant pad clearances based on rotational position, then brake operation response is improved, but uneven abrasion of the disk rotor occurs due to thermal deformation
Solution Approach 1:
The control system dynamically adjusts the pad pressing member position based on real-time detection of disk rotor runout. Instead of maintaining a fixed position based solely on motor rotational angle, the system modifies the target position according to detected runout conditions, enabling adaptive compensation for thermal deformation and runout variations.
Solution Approach 2:
A detection mechanism monitors the actual position of the disk rotor relative to the brake pads and feeds this information back to the control system. The controller uses this feedback to adjust the pad pressing member position, ensuring that pad clearances are maintained uniformly even when thermal deformation causes runout.
2Speed
If small pad clearances are set to quickly perform brake operation, then braking speed is improved, but irregular contact between disk rotor and brake pads occurs
Solution Approach 1:
The system dynamically adjusts pad clearance based on detected runout conditions. When runout is detected, the control system modifies the target position of the pad pressing member to compensate for the irregularities, ensuring uniform contact during braking while maintaining the ability to perform quick brake operations.
3Measurement precision
If the electric motor maintains brake pads in fixed positions when not in operation, then position control accuracy is improved, but uneven abrasion and brake judder occur
Solution Approach 1:
The system transitions from a static position control approach to a dynamic one. When the brake is not in operation, the control system continuously monitors disk rotor runout and adjusts the pad pressing member position accordingly, rather than maintaining a fixed position. This dynamic adjustment prevents uneven abrasion and brake judder caused by thermal deformation.
Solution Approach 2:
The detection mechanism continuously monitors the relationship between the disk rotor and brake pads even when the brake is not in operation. This feedback enables the control system to make real-time adjustments to the pad pressing member position, preventing uneven contact and subsequent brake judder.
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
Prevents uneven abrasion of the disk rotor and reduces the likelihood of brake judder by ensuring consistent pad clearance and controlled retraction of the brake pads, even in the presence of thermal deformation or runout.
Implementation Method 1
an electric motor; a rotation-linear motion converting mechanism for converting a rotational movement of the electric motor into a linear movement
Implementation Method 2
a rotation-linear motion converting mechanism for converting a rotational movement of the electric motor into a linear movement
Implementation Method 3
brake pads are pressed against a disk rotor by the piston, thereby generating a brake force
Data Source
Figure 1~2
Figure 3(A)~5(B)
Figure 6~7
AI summary
An object of the present invention is to, in an electric disk brake, prevent uneven abrasion of a disk rotor due to contact of the disk rotor to a brake pad when brake is not in operation. In the present invention, a rotation of an electric motor is slowed down by a differential speed reducing mechanism, and is converted to a linear motion of a piston by a ball ramp mechanism. Brake pads are pressed against a disk rotor by the piston to generate a brake force. When brake is not in operation, the piton is retracted by a reverse rotation of the electric motor so that a predetermined pad clearance is maintained. When brake is not in operation, a pad-retracting-control electric current is supplied to the electric motor so that the piston is biased backward while being maintained in one position. When brake is not in operation, contact of the disk rotor to the brake pads due to runout of the disk rotor triggers smooth retracting of the piston, whereby uneven abrasion of the disk rotor can be prevented.