Disc Brake Boot Convex Ribs for Pin Stability

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Solution Overview

Problem

The existing disc brake apparatus boot designs either obstruct air flow or suffer from poor productivity due to complex mold splitting issues, and they fail to effectively prevent the slide pin from falling into recesses while sliding, leading to pin rattling and increased processing costs.

Innovation Solution

A boot design with circumferentially arranged convex parts on the inner periphery, featuring high and low-height portions staggered in the axial direction, connected by a curved or planar surface, which prevents the slide pin from falling into recesses and allows air flow without disturbing the sliding process, while improving mold splitting and productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the inner periphery of the boot is formed with convex parts overlapping in a stone wall shape to create recesses for passing air and preventing slide pin from falling in, then the slide pin is prevented from falling into recesses and air flow is maintained, but the mold splitting becomes difficult and productivity deteriorates

Engineering Contradiction:
Improveprevention of slide pin falling into recessVSAvoidmold splitting difficulty
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the geometric parameters of the convex parts by introducing high-height and low-height portions with different axial heights. This parameter variation allows the high-height portions to prevent the slide pin from falling into recesses while the low-height portions maintain air flow passages, all while keeping the overall structure simple enough for easy mold splitting and high productivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Each convex part is segmented into high-height and low-height portions along the axial direction. This segmentation allows different functional zones within the same convex part: the high-height portions provide mechanical support to prevent pin collapse, while the low-height portions maintain open passages for air flow, resolving the contradiction between reliability and productivity

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If the axial length of the boot is lengthened or the number of blocks is increased to suppress elastic deformation of the slide pin, then the slide pin stability is improved, but the layout feature of the caliper or support deteriorates and processing cost increases

Engineering Contradiction:
Improveslide pin stabilityVSAvoidcaliper layout complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention applies local quality by concentrating the stabilizing function in specific high-height portions of the convex parts rather than uniformly increasing the overall boot length or adding multiple blocks. The high-height portions are strategically positioned to provide localized support that suppresses elastic deformation of the slide pin, maintaining stability without increasing overall device complexity or processing cost

Inventive Principle:
Principle #3Local quality

3Reliability

If the boot blocks the axial end portion of the recess to hold grease, then grease retention is improved, but air flow through the recess is blocked and slide pin sliding is disturbed

Engineering Contradiction:
Improvegrease retentionVSAvoidslide pin sliding smoothness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The convex parts are segmented into high-height and low-height portions that create distinct functional zones. The low-height portions maintain open axial passages that allow air to flow through the recesses, ensuring smooth slide pin sliding. Meanwhile, the high-height portions provide structural support to prevent pin collapse, effectively resolving the contradiction between grease retention and sliding smoothness

Inventive Principle:
Principle #1Segmentation

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 effectively suppresses pin rattling, maintains air flow, and enhances productivity by simplifying mold splitting, ensuring the disc brake apparatus operates smoothly and efficiently with reduced processing costs.

Implementation Method 1

a boot made of elastic resin is provided between the slide pin, the guide hole and an entrance

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

it is necessary to enable the air to flow into and out of an extra space in the guide hole so as not to disturb the sliding of the slide pin

Methodology Applied
Scientific EffectAir flow: Convection

Data Source

PatentEP2610519B1Disc brake apparatus
Publication Date: 2016.06.01 AKEBONO BRAKE IND CO LTD
  • EP2610519B1 patent drawingFigure 1
  • EP2610519B1 patent drawingFigure 2~3
  • EP2610519B1 patent drawingFigure 4~5

AI summary

A disc brake apparatus includes a boot (40) including a fitting part (44). A slide pin is fixed to one of a support and a caliper and is slidably mounted to a guide hole formed in the other. Convex parts (52) extending in a sliding direction of the slide pin are circumferentially arranged on an inner periphery of the fitting part (44). Concave recesses (54) are respectively formed between the neighboring convex parts (52). Each of the convex parts is formed with at least one a low-height portion (52b) and a high-height portion (52a) in an axial direction of a rotor, respectively. Positions of the low-height portion (52b) and the high-height portion (52a) in a circumferential direction of the rotor are respectively different between the adjacent convex parts (52). The high-height portion (52a) has a height so as to contact the slide pin, and the low-height portion (52b) has a height so as not to contact the slide pin.