Disc Brake Pad Shim Plate Locking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional disc brake pad assemblies face issues with shim plate separation and interference, leading to instability and noise due to the offset frictional force, which complicates the design and increases the risk of brake squeal and uneven wear.
Innovation Solution
A disc brake pad assembly design where inner and outer shim plates are assembled to allow circumferential displacement while preventing separation, using locking bent portions, through holes, and projecting pieces to engage and restrict radial displacement, thereby reducing the projection of the pad from the pressure plate's edges and facilitating smooth assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a double-plate configuration with inner and outer shim plates is used to suppress brake squeal and partial wear, then the suppression effect is improved, but the device complexity increases and the risk of plate separation occurs
Solution Approach 1:
The inner shim plate is placed inside the outer shim plate, with the inner plate's locking pieces fitting into through-holes of the outer plate. This nested configuration allows both plates to work together for noise suppression while maintaining a compact structure that prevents separation without requiring additional fastening components.
Solution Approach 2:
The locking pieces on the inner shim plate act as intermediaries that engage with the through-holes of the outer shim plate. This intermediary mechanism provides a simple yet effective means of preventing plate separation, avoiding the need for complex fastening systems while maintaining reliability.
2Force
If the frictional portion is offset from the brake torque bearing portion by the thickness of the linings, then the brake torque is effectively borne, but a moment is exerted on the pads causing orientation instability
Solution Approach 1:
The combined shim plates function as a counterbalancing element that offsets the destabilizing moment created by the frictional force offset. By positioning the shim plates between the pressure plate and piston, they provide a counteracting moment that stabilizes pad orientation while allowing the frictional portion to remain offset for effective torque bearing.
3Manufacturing precision
If locking pieces are made to fit precisely between circumferential edges of the pressure plate to prevent radial displacement, then the positioning precision is improved, but the projection of the pad from the pressure plate edges increases
Solution Approach 1:
The locking pieces are designed to engage partially with the pressure plate edges rather than requiring full precision fitment across the entire edge. This partial engagement is sufficient to prevent radial displacement and maintain positioning precision while reducing the overall projection of the pad from the pressure plate edges, minimizing interference with surrounding components.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A pair of locking projecting pieces 19, 19 which are provided individually at both circumferential end edges of an outer shim plate 4a are brought into engagement with locking through holes 16, 16 which are formed in base end portions of a pair of locking bent portions 15, 15 which are provided individually at both circumferential end portions of an inner shim plate 3a, whereby the separation of both the shim plates 3a, 4a is prevented. Inner locking pieces 8d, 8e, 8f and outer locking pieces 13d, 13e, 13f which are formed on the shim plates 3a, 4a, respectively, and which are brought into engagement with circumferential edge portions of a pressure plate 2a are never fittingly superposed on each other, and therefore, the projection thereof from inward and outward circumferential edges of the pressure plate 2a is suppressed.