Compressed Air Check Valve Hold-Down Noise Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vent or non-return valves in automotive applications face challenges in minimizing noise generation while maintaining good sealing properties, as flexible membrane materials tend to vibrate and cause structure-borne noise, while rigid membranes compromise sealing.

Innovation Solution

The implementation of hold-down devices on the valve housing that locally press the radially outer region of the diaphragm disk against the valve seat, increasing clamping rigidity and preventing large-area vibration, thereby reducing airborne noise and ensuring high air throughput, low throttling, and reliable dirt prevention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flexible membrane material is used, then sealing properties are improved, but noise generation increases due to vibration

Engineering Contradiction:
Improvesealing propertiesVSAvoidnoise generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by providing hold-down devices at specific locations (radially outer region) of the diaphragm disk rather than uniformly across the entire membrane. This localized clamping maintains sealing properties at the valve seat while reducing vibration amplitude in the radially outer region, thereby decreasing airborne noise radiation from that area.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If rigid membrane material is used, then noise generation is reduced, but sealing properties deteriorate

Engineering Contradiction:
Improvenoise generationVSAvoidsealing properties
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent changes the parameter of clamping force distribution by introducing hold-down devices that apply localized pressure to the radially outer region of the diaphragm disk. This creates a non-uniform stress distribution in the membrane, allowing the central region to maintain flexibility for good sealing while the clamped outer region has reduced vibration amplitude for lower noise.

Inventive Principle:
Principle #35Parameter changes

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 design effectively reduces noise generation, maintains high air throughput, prevents undesired flow, and ensures reliable sealing and dirt exclusion, while maintaining low opening pressure.

Implementation Method 1

several hold-down devices (6), which are arranged at a circumferential distance from one another, hold down the radially outer region of the diaphragm disk (2) against the valve seat (4) locally

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

vent or non-return valves which open when a pressure difference between an inlet chamber and an outlet chamber has reached or exceeded an opening pressure of the vent or non-return valve

Methodology Applied
Scientific EffectPressure Gradient: Pressure Gradient

Data Source

PatentEP2948701B1Check valve for ventilation or outlet openings of compressed air apparatuses in vehicles
Publication Date: 2018.11.28 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH
  • EP2948701B1 patent drawingFigure 1~2

AI summary

The invention relates to a ventilation or check valve for ventilation or outlet openings of compressed air apparatuses in vehicles, comprising at least one diaphragm disc (2) which is made of flexible material, is held with a central region in a bore of a valve housing and is prestressed with a radially outer region against a valve seat (4) on the valve housing (4) in order to lift off from the valve seat (4) in a pressure-induced manner in the event of a pressure gradient between an input space and an output space or the atmosphere and to open a flow cross section between the input space and the output space or the atmosphere. According to the invention, a plurality of holders (5, 6) are provided on the valve housing (3) as seen in the circumferential direction of the diaphragm disc (2), said holders being arranged at a circumferential distance from one another and locally holding down the radially outer region of the diaphragm disc (2) against the valve seat (4).