Disc Brake Pad Preload Spring for Knocking Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Disc brakes in motor vehicles experience parasitic knocking noises due to excessive kinetic energy storage and release during gear shifts, caused by transverse functional clearance between the brake pad and carrier, leading to instability and unreliable torque determination upon contact.
Innovation Solution
A tangential preload spring is introduced between the brake pad and the carrier's lamellar element, compressing the brake pad to reduce clearance and damp transverse movements, ensuring a consistent and reduced clearance between the brake pad and the transverse bearing flange, thereby reducing noise and maintaining operational stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If transverse functional clearance is provided between brake pad and carrier, then brake pad can slide properly and prevent jamming, but excessive clearance causes kinetic energy storage and release leading to knocking noise
Solution Approach 1:
A tangential preload spring is introduced as an intermediary element between the brake pad and carrier. This spring applies a constant tangential force that preloads the brake pad against the carrier, reducing the transverse clearance while maintaining the necessary sliding capability. The spring acts as a mediator that simultaneously achieves both proper brake pad operation and noise reduction.
Solution Approach 2:
The invention changes the physical state of the brake pad-carrier interface by applying a constant tangential force through the preload spring. This force modifies the clearance parameter, transforming it from a large variable clearance to a small controlled clearance, thereby reducing the kinetic energy storage and eliminating knocking noise while preserving sliding functionality.
2Reliability
If transverse functional clearance is increased to prevent brake pad jamming, then sliding operation is improved, but kinetic energy storage increases causing noise upon contact
Solution Approach 1:
The tangential preload spring performs a preliminary action by preloading the brake pad against the carrier before braking occurs. This preliminary tangential force reduces the clearance in advance, so that when the brake pad moves during operation, the clearance is already minimized, preventing the buildup of kinetic energy that would cause knocking noise.
Solution Approach 2:
The preload spring serves as an intermediary mechanism that applies a continuous tangential force to maintain optimal clearance. This intermediary element ensures reliable sliding operation while simultaneously preventing the harmful knocking noise by controlling the clearance throughout the braking cycle.
3Ease of operation
If brake pad is allowed to move freely in transverse direction, then axial sliding is facilitated, but energy storage and release causes unstable contact and noise
Solution Approach 1:
The invention changes the transverse position parameter of the brake pad by applying a constant tangential preload force. This force shifts the brake pad to a predetermined position with reduced clearance, stabilizing the contact while preserving the ability to slide axially during braking operation.
Solution Approach 2:
The tangential preload spring acts as an intermediary that applies a stabilizing tangential force, creating a preloaded contact state. This intermediary force ensures stable contact between brake pad and carrier while allowing necessary axial sliding motion during braking.
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 reduces noise generation and maintains operational stability by minimizing energy storage and release during gear shifts, ensuring reliable torque determination and consistent contact between the brake pad and carrier.
Implementation Method 1
a tangential preload spring which constantly urges the brake pad in a direction that is horizontal overall, from the back forward
Implementation Method 2
a brake pad guiding spring which is fixed to the associated lug of the brake pad and which comprises at least one sliding lower branch which collaborates with the lower face of the associated housing and which urges the said upper facet of the lug to press vertically upwards against the upper face of the associated housing
Implementation Method 3
the brake pad is subjected to the tangential forces or loads applied via the friction forces exerted on a friction lining of the brake pad as a result of the contact between this friction lining and an associated annular face of the brake disc
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention proposes a disc brake of which a carrier (11 ) comprises two opposite arms (14F, 14B) each comprising a C-shaped axial housing (16F, 16B) accommodating a brake pad (12) comprising two opposite lateral lugs (26F, 26B), each lug (26) accepting a pad spring (40F, 40B) comprising at least one lower, sliding, branch (42F, 42B) and in which a lamellar element (22F, 22B) is interposed between the lug (26F, 26B) and the C-shaped housing (16F, 16B), this element (22F, 22B) comprising a lower first sliding flange (24F, 22B) accepting the sliding branch (42F, 22B) of the pad spring (40F, 40B) and an upper second flange (25F, 25B) for bearing vertically in the housing (16), characterized in that it comprises at least one tangential preload spring (60B) for tangentially preloading the pad (12) and which is interposed between an arm (14B) and the pad (12) and constantly urges the pad (12B) in a direction (DF) that is horizontal overall from the back forward.