Disc Brake Pad Spring Biasing for Abraded Pad Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional disc brake rotational direction biasing portions apply a constant force to friction pads, leading to excessive force on abraded pads and generation of abnormal noises like brake noise and clonking noise.
Innovation Solution
The disc brake design incorporates a pad spring with a guide plate portion and a rotational direction biasing portion that includes a main and sub biasing portion, with the sub biasing portion applying a smaller force closer to the disc, adjusting the biasing force based on the pad's position to prevent excessive force on abraded pads and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a constant biasing force is applied to the friction pad by the rotational direction biasing portion, then the friction pad is properly biased when new, but excessive force is applied when the pad is abraded, causing abnormal noises
Solution Approach 1:
The rotational direction biasing portion is designed with two different lengths in the disc axial direction, creating unequal biasing forces that dynamically adapt to the friction pad's wear state. The longer portion provides greater biasing force when the pad is new, while the shorter portion provides reduced biasing force when the pad is abraded, preventing excessive force and abnormal noises throughout the pad's service life.
Solution Approach 2:
The biasing force distribution is made non-uniform along the disc axial direction by configuring the rotational direction biasing portion with different lengths. This creates localized variations in biasing force, with the longer portion applying greater force and the shorter portion applying lesser force, allowing the system to adapt to different wear stages of the friction pad.
2Duration of action of stationary object
If the friction pad mass decreases due to abrasion, then the pad wears down to extend service life, but the constant biasing force becomes excessive relative to the reduced mass, causing instability and noise
Solution Approach 1:
The biasing force is made dynamic through the unequal lengths of the rotational direction biasing portion, allowing the system to automatically adjust the applied force as the friction pad wears. This dynamic adaptation maintains system stability throughout the pad's service life, preventing the excessive force that would cause instability and noise in abraded pads.
3Device complexity
If a single uniform biasing structure is used, then the design is simple, but it cannot provide differentiated biasing force for new and abraded pads
Solution Approach 1:
The rotational direction biasing portion is segmented into two distinct sections with different lengths in the disc axial direction. This segmentation allows each section to provide a different biasing force, with the longer section providing greater force and the shorter section providing lesser force, enabling the structure to adapt to both new and abraded pad conditions.
Solution Approach 2:
Different portions of the rotational direction biasing portion are given different lengths to create localized variations in biasing force. This local differentiation allows the same structural element to provide adaptively different forces at different locations, maintaining both structural simplicity and functional versatility.
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 design reduces abnormal noises by ensuring the friction pads are properly biased, maintaining stability and smooth operation even when pads are abraded, thereby improving brake performance and reducing noise.
Implementation Method 1
a pad spring mounted on the mounting member on a side where at least one of the arm portions is located, the pad spring being configured to elastically support the friction pad between the arm portions
Implementation Method 2
a pair of friction pads that includes ear portions inserted in the pad guides of the mounting member and is pressed by the caliper against both surfaces of the disc
Data Source
AI summary
At least one of a pair of pad springs includes a guide plate portion for guiding an ear portion of a corresponding friction pad in a disc axial direction. The guide plate portion includes a first plate portion, a second plate portion, and a bottom plate apportion. A radially biasing portion is configured to elastically bias the ear portion of the friction pad toward the first plate portion; and a rotational direction biasing portion is configured to bias the friction pad in a rotational direction of a disc. The second plate portion is provided with an open portion at a position shifted inward from a middle position in the disc axial direction. The rotational direction biasing portion includes a main biasing portion configured to bias the friction pad inward in the disc rotational direction, and a sub biasing portion arranged across the open portion away from the main biasing portion.