Parking Brake Device Automatic Engagement via Pressure Release

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Solution Overview

Problem

Existing parking brake devices for vehicles carrying dangerous goods cannot ensure safe engagement of the parking brake when the electrical main switch interrupts the energy supply, posing a risk of unintentional vehicle movement.

Innovation Solution

A parking brake device with multiple states that automatically engages the brake when the electrical energy supply is interrupted, utilizing a bistable solenoid valve and pressure medium lines to maintain the brake engaged without continuous energy consumption, and includes a pressure-sensing mechanism to prevent unintentional engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the electrical energy supply is interrupted by the main switch, then energy consumption is reduced and safety risk is minimized, but the parking brake can no longer be engaged and the vehicle cannot be parked safely

Engineering Contradiction:
Improvesafe parkingVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent inverts the conventional logic by designing the parking brake to automatically engage when electrical energy is interrupted, rather than requiring continuous power to maintain the braked state. The spring-loaded brake cylinder engages the parking brake when pressure is released, and the system automatically releases the brake when power is restored and pressure is reapplied to the first pressure medium line.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The parking brake device uses the interruption of electrical energy itself as the trigger mechanism for engagement. When the main switch cuts power, the loss of electrical pressure automatically causes the spring-loaded brake cylinder to engage the parking brake without requiring additional mechanical intervention or external actuation.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If the parking brake device maintains the second state (parking brake released) continuously, then the vehicle can be driven freely, but electrical energy must be continuously supplied causing heat dissipation and energy loss

Engineering Contradiction:
Improvevehicle drivabilityVSAvoidheat dissipation
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent implements periodic action by only supplying electrical energy when necessary - specifically, when the vehicle is in motion and the parking brake should be released. When the vehicle is stationary or the parking brake should be engaged, the electrical supply is interrupted and the system operates in a passive state, eliminating continuous heat dissipation and energy loss.

Inventive Principle:
Principle #19Periodic action

3Reliability

If the parking brake device is designed to automatically engage when electrical supply is interrupted, then safety is improved, but the device complexity increases with multiple states and pressure medium lines

Engineering Contradiction:
Improveautomatic brake engagementVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs pneumatic principles using a spring-loaded brake cylinder where a flexible membrane separates a first pressure medium line (electrical pressure medium) from a second pressure medium line (non-electrical pressure medium). This pneumatic/hydraulic design enables automatic state transitions based on pressure differential without requiring complex mechanical linkages or additional actuators.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

Ensures safe and energy-efficient operation of the parking brake, preventing unintentional vehicle movement even when the electrical energy supply is interrupted, while allowing low-energy operation during normal driving conditions.

Implementation Method 1

a spring-loaded brake cylinder (60), wherein the brake cylinder (60) is acted upon by a pressure present in the first pressure medium line (26)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

A parking brake device with multiple states that automatically engages the brake when the electrical energy supply is interrupted, utilizing a bistable solenoid valve

Methodology Applied
Scientific EffectSolenoid: Solenoid

Data Source

PatentEP2199162B1Method for operating a parking brake device, parking brake device, brake unit for implementing the procedure, brake unit with this parking brake device and vehicle for implementing the procedure and/or with this parking brake device and/or with this braking unit
Publication Date: 2019.08.07 ZF CV SYST HANNOVER GMBH
  • EP2199162B1 patent drawingFigure 1
  • EP2199162B1 patent drawingFigure 2
  • EP2199162B1 patent drawingFigure 3

AI summary

The method involves guiding a pressure medium with pressure into a pressure medium line (26). The pressure is reduced up to a minimum pressure i.e. circumferential air pressure, for actuating a brake cylinder (60) i.e. spring-loaded brake cylinder in a state. The pressure is maintained in another state, where a hand brake device (1) takes up the latter state when a vehicle is in standstill and a hand brake is disengaged. The device is moved to the former state in a case that supply of electrical energy is interrupted during the latter state so that the hand brake is engaged.