Dual Master Cylinder Brake Assembly with Quick-Fill Spool

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Increased brake running clearances in vehicles require more hydraulic fluid volume, necessitating additional energy for pressurization, which is inefficient and requires a compact brake system that can take up clearances without additional hydraulic power components.

Innovation Solution

A hydraulic brake assembly with a quick-fill function, featuring a dual master cylinder design where a spool directs hydraulic fluid from a quick-fill chamber to the master cylinder chamber upon initial brake application, taking up clearances, and then to a tank when pressure reaches a threshold, allowing continued brake actuation with higher pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If brake running clearances are increased to improve fuel efficiency, then fuel efficiency is improved, but more hydraulic fluid volume is required and additional energy is needed for pressurization

Engineering Contradiction:
Improvefuel efficiencyVSAvoidhydraulic fluid volume
Core Design Contradiction:
Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The master cylinder piston is segmented into two portions with different diameters, creating two distinct chambers (quick-fill chamber and master cylinder chamber) that perform different functions. The larger diameter portion creates the quick-fill chamber for rapid clearance take-up, while the smaller diameter portion creates the master cylinder chamber for sustained brake pressure, allowing the system to handle increased fluid volume requirements without additional energy input.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The quick-fill chamber is pre-filled with hydraulic fluid and positioned to automatically supply fluid to take up brake clearances upon initial piston movement. This preliminary action of clearance take-up occurs before the main braking phase, eliminating the need for additional energy input during the braking process itself.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If more hydraulic fluid volume is used to take up clearances, then clearance take-up capacity is improved, but additional energy for pressurization is required

Engineering Contradiction:
Improvehydraulic fluid volumeVSAvoidenergy for pressurization
Core Design Contradiction:
Quantity of substanceVSUse of energy by stationary object

Solution Approach 1:

The quick-fill chamber uses the initial movement of the master cylinder piston to automatically pressurize and distribute hydraulic fluid to take up brake clearances. The system serves itself by using the piston's own movement to generate the pressure needed for clearance take-up, eliminating the need for external hydraulic power components or additional energy input.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention uses hydraulic pressure generated by the master cylinder piston's movement to automatically take up clearances. The hydraulic system is designed so that the initial piston movement creates sufficient pressure to force fluid into the brake lines and take up clearances without requiring additional energy input from external sources.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Device complexity

If a compact brake system is used to avoid additional components, then device complexity is reduced, but the ability to take up clearances without additional hydraulic power may be limited

Engineering Contradiction:
Improvenumber of hydraulic power componentsVSAvoidclearance take-up capability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The master cylinder piston serves multiple functions: it acts as both the actuating element for brake application and the pump element for clearance take-up. The dual-chamber design allows the same component to handle both rapid clearance elimination and sustained brake pressure generation, eliminating the need for separate hydraulic power components while maintaining full clearance take-up capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The quick-fill chamber is nested within the master cylinder assembly, with the larger diameter portion of the piston creating an internal chamber that is integrated into the overall master cylinder structure. This nested design allows the clearance take-up function to be incorporated within the existing brake system geometry without adding external components.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 system efficiently takes up brake clearances with initial brake application, reducing the need for additional hydraulic power components and maintaining effective brake pressure for vehicle retardation or stopping.

Implementation Method 1

direct hydraulic fluid from the quick-fill chamber to the master cylinder chamber and the brakes at a first pressure

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Gradient

Implementation Method 2

The hydraulic fluid from the quick-fill chamber takes up any clearance between the friction elements of the brakes

Methodology Applied
Scientific EffectHydraulic fluid flow: Hydraulic Press

Data Source

PatentEP3500463B1Dual master cylinder brake assembly with quick-fill function
Publication Date: 2022.04.06 CARLISLE IND BRAKE & FRICTION
  • EP3500463B1 patent drawingFigure 1A
  • EP3500463B1 patent drawingFigure 1B
  • EP3500463B1 patent drawingFigure 2

AI summary

A hydraulic brake assembly (12) includes a housing (24) having first and second side-by-side bores (30), each defining a respective master cylinder assembly. Each master cylinder assembly includes a master cylinder piston (32) slidably movable by actuation of a respective brake pedal (18a, 18b) to and between an active position and an inactive position. A spool (74) slidably disposed within a piston bore (70) of the master cylinder piston (32) is operable in a first mode to direct hydraulic fluid from a quick-fill chamber (62) to a master cylinder chamber (50) at a first pressure upon initial movement of the master cylinder piston (32) from the inactive position toward the active position. The spool (74) is operable in a second mode to direct hydraulic fluid from the quick-fill chamber (62) to a tank (20) when pressure in the master cylinder chamber (50) reaches a predefined threshold.