Pressure Protection Flap Control Using Simulated Cabin Pressure

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Solution Overview

Problem

Existing pressure relief devices in vehicles, such as rail vehicles, struggle with accurately detecting critical pressure events without false triggering, leading to reduced pressure comfort and air quality issues due to improper flap operation.

Innovation Solution

A pressure protection device that calculates pressure difference using a reference device simulating internal pressure when flaps are closed, utilizing a capillary throttle valve and solenoid valves to accurately measure differential pressures, preventing false triggers and ensuring proper flap operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the pressure relief device is optimized to ensure reliable detection of the flaps closing, then the detection accuracy is improved, but the reopening detection becomes unreliable leading to excessive CO2 concentrations

Engineering Contradiction:
Improvepressure difference detection accuracyVSAvoidflap operation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The pressure difference measurement system is segmented into two distinct measurement paths: one for detecting flap closing (using actual internal pressure) and one for detecting flap reopening (using simulated internal pressure). This segmentation allows each measurement path to be optimized for its specific detection purpose without interfering with the other, resolving the contradiction between reliable closing detection and reliable reopening detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A reference device is introduced as an intermediary element that simulates the internal pressure behavior when flaps are closed. This reference device acts as a mediator between the external pressure and the measurement system, providing a stable reference pressure that enables accurate reopening detection without affecting the closing detection accuracy. The reference device includes a reference air connection, reference air reservoir, and reference throttle valve that together simulate the pressure characteristics of a closed vehicle interior.

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

Enhances accurate detection of critical pressure events, improving pressure comfort and maintaining high air quality by reducing false triggers and ensuring timely flap operation.

Implementation Method 1

the throttle valve is designed as a capillary whose effective length and/or effective diameter is adjustable

Methodology Applied
Scientific EffectCapillary flow restriction: Capillary Action

Implementation Method 2

When the at least one pressure protection flap is closed, the pressure evaluation device opens the solenoid valve

Methodology Applied
Scientific EffectElectromagnetic actuation: Solenoid

Data Source

PatentEP4466172B1Vehicle for passenger transport with a pressure protection device
Publication Date: 2025.12.17 SIEMENS MOBILITY GMBH
  • EP4466172B1 patent drawingFigure 1
  • EP4466172B1 patent drawingFigure 2

AI summary

The invention relates to a vehicle for passenger transport, comprising at least one air opening, which connects an environment (U) of the vehicle, having an external pressure, to an interior (I) of the vehicle provided for accommodating people and having an interior pressure, at least one pressure protection flap (2) for opening or closing the air opening and a pressure protection device for controlling the at least one pressure protection flap (2), wherein the pressure protection device has a measuring device (3) for detecting a pressure difference between the external pressure at an external pressure connection (5) of the measuring device (3) and the interior pressure at an interior pressure connection (6) of the measuring device (3), as well as a pressure evaluation device (1) for monitoring the pressure difference values delivered by the measuring device (3), wherein the pressure evaluation device (1) is designed in such a way that, when the pressure difference reaches a predefined closing threshold value, it triggers a closing of the at least one pressure protection flap (2), and if the pressure difference reaches a predefined opening threshold value, it triggers an opening of same, wherein the pressure protection device is designed in such a way that, in the event that the at least one pressure protection flap (2) is opened, at the measuring device (3), the pressure difference is formed from the external pressure and a reference interior pressure provided by a reference device (7), which emulates an interior pressure behaviour of the vehicle when the pressure protection flap (2) is closed.