Brake Disc Rigidity Layout for Squeal and Vibration Reduction
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Solution Overview
Problem
Disc brakes experience vibrations and noise, particularly high-frequency squeaking, during braking due to circumferential waves on the braking band, which existing solutions fail to adequately minimize.
Innovation Solution
A brake disc design featuring seven regions of alternating high and low rigidity, connected by a prime number of elements, including hollow pin connecting elements and flow-diverting fins, to reduce vibrations and enhance braking comfort and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional brake disc design is used, then the braking function is provided, but vibrations and high-frequency squeaking occur during braking
Solution Approach 1:
The brake disc is segmented into multiple regions with alternating rigidity characteristics (rigid and compliant regions) arranged circumferentially. This segmentation creates different vibration modes that interfere with each other, reducing the amplitude of circumferential waves and preventing squeaking noises during braking.
Solution Approach 2:
Different regions of the brake disc are given different local qualities - some regions have higher rigidity while others have lower rigidity. This local variation in mechanical properties allows the disc to have optimized vibration characteristics in different zones, reducing overall vibrations and noise while maintaining effective braking surfaces.
2Strength
If the number of connecting elements is increased, then the structural rigidity is improved, but the vibrations and noise are amplified
Solution Approach 1:
Instead of using many uniformly distributed connecting elements, the design uses a limited number of connecting elements (5-7) strategically positioned to create alternating rigid and compliant regions. This segmented approach provides sufficient structural strength while allowing certain regions to deform and absorb vibration energy, reducing noise.
Solution Approach 2:
The rigidity parameter is varied spatially around the brake disc circumference by changing the number and position of connecting elements. This creates a non-uniform rigidity distribution with alternating high and low rigidity regions, which modifies the vibration characteristics to reduce squeaking while maintaining overall structural integrity.
3Object-affected harmful factors
If the number of connecting elements is decreased, then the vibrations are reduced, but the structural strength is compromised
Solution Approach 1:
The connecting elements are strategically positioned to create local variations in rigidity. Regions with connecting elements provide structural strength and stability, while regions without connecting elements provide compliance and vibration absorption. This local differentiation allows the structure to be strong where needed and flexible where beneficial for vibration reduction.
Solution Approach 2:
The distribution of connecting elements creates an asymmetric pattern of rigid and compliant regions around the disc circumference. This asymmetric arrangement breaks the symmetry of vibration modes, preventing the formation of standing waves that cause squeaking, while maintaining sufficient structural strength through the strategically placed connections.
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 significantly reduces vibrations and noise, providing improved braking comfort and thermal performance by minimizing circumferential waves and optimizing ventilation and heat dissipation.
Implementation Method 1
hollow pin connecting elements... facilitating the disposal of the heat generated during the braking action
Implementation Method 2
connecting elements... connected to said braking band... facilitating the disposal of the heat generated
Implementation Method 3
flow-diverting fins which direct the cooling air towards the ventilation duct of the braking band
Implementation Method 4
a series of areas, of portions, which alternatively show a relatively high and a relatively low rigidity... reduces vibrations and in particular an absence of vibrations which lead to squeaking
Data Source
AI summary
A braking device for a vehicle capable of resulting in an increased driving comfort is provided. The braking device may have a brake disc of a disc brake for rotating about a rotation axis, in which the disc may have a disc body. The disc body may have a braking band having opposite braking surfaces and at least one connection portion for connecting the disc to a connection device of a vehicle associable with the braking device. The braking band defines an axial direction parallel to the rotation axis of the brake disc, a radial direction orthogonal to the axial direction and a tangential or circumferential direction orthogonal both to the axial direction and to the radial direction. The connection portion is connected to the braking band by connecting elements, the connecting elements being a plurality of elements equally spaced apart in circumferential direction.