Waveform Brake Disc Heat Capacity Layout for Stable Brake Feel

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Solution Overview

Problem

Brake discs with waveform portions experience increased temperature irregularity and degraded brake feeling due to their complex shapes, and increasing the heat capacity to improve brake feeling leads to increased weight.

Innovation Solution

A brake disc design with an inner circumferential portion as a non-sliding area and through-holes across the boundary between the outer and inner circumferential portions, along with asymmetric recessed and projecting portions, to enhance cooling efficiency and uniform heat capacity distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If waveform portions are formed on the brake disc to remove brake pad powder, then cleaning efficiency is improved, but temperature irregularity increases and brake feeling degrades

Engineering Contradiction:
Improvecleaning efficiencyVSAvoidtemperature irregularity
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The brake disc is divided into multiple radial sections with different heat capacities. By segmenting the disc structure and assigning different functions to different sections (some with waveform portions for cleaning, others optimized for heat storage), the patent achieves both effective brake pad cleaning and uniform temperature distribution across the disc.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the brake disc are given different local properties. The waveform portions are strategically placed in specific radial sections to optimize cleaning where needed, while other sections are designed with appropriate heat capacities to maintain uniform temperature distribution, creating local quality variations that resolve the contradiction.

Inventive Principle:
Principle #3Local quality

2Temperature

If the heat capacity of the brake disc is increased to improve brake feeling, then temperature uniformity is improved, but the weight of the brake disc increases

Engineering Contradiction:
Improvetemperature uniformityVSAvoidbrake disc weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

Instead of uniformly increasing the heat capacity of the entire brake disc (which would increase weight), the patent applies different heat capacity characteristics to different radial sections. This localized approach allows specific sections to provide heat storage where needed for temperature uniformity, while other sections maintain lower mass, thus achieving the desired thermal performance without proportional weight increase.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The brake disc is segmented into radial sections with differentiated heat capacity characteristics. This segmentation allows the system to achieve overall temperature uniformity through coordinated thermal management across sections, rather than requiring the entire disc to have high heat capacity, thereby avoiding unnecessary weight increase.

Inventive Principle:
Principle #1Segmentation

3Temperature

If the areas of brake front and back surfaces are increased to increase heat capacity, then brake feeling is improved, but the weight of the brake disc increases

Engineering Contradiction:
Improveheat capacityVSAvoidbrake disc weight
Core Design Contradiction:
TemperatureVSWeight of moving object

Solution Approach 1:

The patent varies the heat capacity characteristics locally across different radial sections of the brake disc rather than uniformly increasing surface areas. This allows the system to achieve the necessary heat capacity for improved brake feeling through strategic placement of thermal mass in specific sections, minimizing overall weight increase compared to uniform area expansion.

Inventive Principle:
Principle #3Local quality

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 design achieves improved brake feeling by reducing temperature irregularity and increasing surface area for better cooling efficiency without significantly increasing weight.

Implementation Method 1

through-holes are formed across a boundary line between the outer circumferential portion and the inner circumferential portion... increase surface area of a side surface of the brake disc to thereby achieve desired cooling efficiency

Methodology Applied
Scientific EffectHeat dissipation: Convection

Implementation Method 2

increase surface area of a side surface of the brake disc to thereby achieve desired cooling efficiency

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP3943375B1Brake disc
Publication Date: 2025.09.03 SUNSTAR GIKEN KK
  • EP3943375B1 patent drawingFigure 1~2
  • EP3943375B1 patent drawingFigure 3
  • EP3943375B1 patent drawingFigure 4

AI summary

To improve brake feeling of a brake disc including a waveform portion in which recessed portions and projecting portions are repeatedly formed over an outer circumference. A brake disc 1 includes an outer circumferential portion 2 including a waveform portion 10 in which recessed portions 10a and projecting portions 10b are repeatedly formed over an outer circumference, and in order for the outer circumferential portion 2 to have substantially uniform heat capacity distribution in a circumferential direction and in a radial direction, the outer circumferential portion 2 is formed such that a ratio of a difference in heat capacities among a plurality of circumferential sections in the outer circumferential portion, which are sectioned at an equal angle in the circumferential direction, relative to a heat capacity of each circumferential section is equal to or less than a first predetermined ratio, and a ratio of a difference in heat capacities among a plurality of radial sections in the outer circumferential portion, which are sectioned to have an equal length in the radial direction, relative to a heat capacity of each radial section is equal to or less than a second predetermined ratio.