Brake Booster Jump-In Force Consistency via Reaction Disc Sorting

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Solution Overview

Problem

Vehicle brake boosters exhibit inconsistent jump-in force characteristics due to variations in reaction disc performance, leading to inconsistent brake pedal feel across vehicles, as existing manufacturing methods fail to accurately match plunger plate lengths with reaction discs to achieve a desired jump-in force.

Innovation Solution

A method involving load testing of elastic reaction discs to determine jump-in force, followed by selecting and adjusting plunger plate axial lengths to pair with reaction discs, ensuring consistent jump-in force by grouping and tailoring plunger plates to match specific batches of reaction discs, thereby reducing discrepancies between tested and desired jump-in forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional manufacturing methods are used without load testing reaction discs, then production efficiency is maintained, but jump-in force consistency deteriorates

Engineering Contradiction:
Improvejump-in force consistencyVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The reaction disc is load tested before final assembly to determine its actual jump-in force characteristics. This preliminary testing allows the plunger plate axial length to be selectively adjusted based on measured performance, ensuring consistent jump-in force while maintaining production efficiency through batch processing and selective assembly

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The axial length of the plunger plate is varied as a compensating parameter to account for variations in reaction disc performance. By adjusting this dimensional parameter based on load test results, the system achieves consistent jump-in force despite variations in reaction disc characteristics

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If plunger plate axial length is fixed, then manufacturing simplicity is maintained, but jump-in force variation increases

Engineering Contradiction:
Improvejump-in force controlVSAvoidplunger plate selection process
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Different plunger plates with specific axial lengths are selectively assigned to different reaction discs based on their measured performance characteristics. This localized customization ensures optimal jump-in force for each component pair while maintaining overall manufacturing efficiency through systematic categorization

Inventive Principle:
Principle #3Local quality

3Reliability

If reaction disc variations are not compensated, then manufacturing process remains simple, but brake pedal feel consistency deteriorates

Engineering Contradiction:
Improvebrake pedal feel consistencyVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Load testing provides feedback on actual reaction disc performance, which is used to select or adjust the plunger plate axial length. This feedback loop compensates for reaction disc variations and ensures consistent jump-in force and brake pedal feel across all vehicles

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The plunger plate axial length acts as an intermediary parameter that mediates between reaction disc variations and jump-in force output. By adjusting this intermediate dimension, the system compensates for reaction disc inconsistencies and achieves reliable brake pedal feel

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This approach significantly improves the consistency of brake booster jump-in characteristics, resulting in more uniform brake pedal feel across vehicles without requiring significant changes to the production of reaction discs, ensuring better manufacturing efficiency and quality control.

Implementation Method 1

An elastic reaction disc is provided for assembly in the brake booster between an input member and an output member

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3492327B1Method of manufacturing brake boosters
Publication Date: 2020.09.09 ROBERT BOSCH GMBH
  • EP3492327B1 patent drawingFigure 1
  • EP3492327B1 patent drawingFigure 2
  • EP3492327B1 patent drawingFigure 3

AI summary

A method of manufacturing vehicle brake boosters includes load testing a plurality of reaction discs (36) and sorting the load-tested reaction discs into multiple, separate batches based on the load test results. A first batch of plunger plates (40) is formed to an axial length to correspond with a first of the separate batches of reaction discs. A first batch of the vehicle brake boosters is assembled with a first one of the multiple, separate batches of reaction discs (36) and the first batch of plunger plates (40) to achieve a target jump-in force. A second batch of plunger plates (40) is formed to an axial length to correspond with a second one of the separate batches of reaction discs (36). A second batch of the vehicle brake boosters is assembled with a second one of the multiple separate batches of reaction discs and the second batch of plunger plates to achieve the target jump-in force.