Brake Pad Return Spring Assembly for Constant Clearance Control
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Solution Overview
Problem
Conventional friction lining arrangements with return springs made of sheet metal fail to maintain a consistently dimensioned clearance as the friction material wears, leading to increased brake pedal travel and potential residual braking torque.
Innovation Solution
The friction lining arrangement incorporates a return spring with a spring arm that engages over a hammerhead-shaped claw and can be plastically deformed due to frictional wear, allowing for automatic and constant dimensioning of the clearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional return spring with fixed spring leg is used, then residual braking torque is avoided, but the clearance increases with friction material wear leading to longer pedal travel
Solution Approach 1:
The spring leg is designed to change its position dynamically relative to the friction lining arrangement as wear occurs. The spring leg can move along the friction lining arrangement, allowing it to maintain optimal spring force and clearance dimensioning throughout the service life of the brake pad, adapting to wear rather than remaining fixed.
Solution Approach 2:
The invention changes the parameter of spring leg position from fixed to variable. By allowing the spring leg to move or adjust its position along the friction lining arrangement, the spring can maintain constant clearance dimensioning despite changes in friction material thickness due to wear.
2Manufacturing precision
If the spring arm is designed to be plastically deformed by frictional wear, then automatic clearance dimensioning is achieved, but the spring structure becomes more complex
Solution Approach 1:
The spring arm automatically adjusts the clearance through plastic deformation caused by frictional wear during normal brake operation. The wear process itself serves the function of adjusting the clearance, eliminating the need for separate adjustment mechanisms or complex control systems.
Solution Approach 2:
The invention converts the harmful effect of frictional wear, which normally degrades components, into a beneficial self-adjusting mechanism. The frictional wear that would normally be considered damage is instead utilized to automatically dimension and maintain the optimal clearance between the brake pad and rotor.
3Ease of manufacture
If the return spring is directly clamped to the brake holder, then assembly is simplified, but stone chip protection is reduced
Solution Approach 1:
The spring leg acts as an intermediary element between the return spring and the friction lining arrangement. It provides both the clamping function for simplified assembly and the protective function by serving as a barrier against stone chips and debris, while also enabling the dynamic adjustment 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
This solution ensures that the clearance is maintained optimally with friction material wear, preventing residual braking torque and maintaining efficient brake pedal travel, while also being robust and reducing production and assembly complexity.
Implementation Method 1
the spring arm of which engages over a hammerhead-shaped claw, and wherein the spring arm is provided so that it can be plastically deformed in a targeted manner due to frictional wear of the friction material and/or brake disc under braking
Implementation Method 2
frictional wear of the friction material and/or brake disc under braking
Implementation Method 3
the return spring is clamped between the brake holder and the friction lining arrangement, the return spring is fixed to a back plate of the friction lining arrangement, and is supported by a spring leg in an axially resilient manner on the brake holder
Data Source
Figure 1a~1b
Figure 2~4
Figure 5~6
AI summary
The invention relates to a friction lining assembly having a backing plate (14) and having a restoring spring of sheet metal fastened thereto, for a motor-vehicle partially lined disk brake (1) of the sliding-caliper type having a vehicle-fixed brake holder (2), on which friction lining assemblies arranged on both sides of a brake disk are slidably guided, and having a housing (3), which extends over the brake disk and the friction lining assemblies and which is slidably mounted on the brake holder (2), wherein the restoring spring can be clamped axially between the brake holder (2) and the friction lining assembly by means of at least one spring leg (13) in such a way that the restoring spring applies a clearance to the friction lining assembly. The spring leg (13) extends over a hammer-head-shaped claw (6) of the backing plate (14), wherein the spring leg (13) is designed to be deliberately plastically deformable under braking actuation as a result of a reduction in the friction-material thickness in order to apply a constantly dimensioned clearance to the friction lining assembly.