Silencer Annular Cavity Weld Flash Containment

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Solution Overview

Problem

Existing silencers face issues with welding flash causing contamination, clearance problems, and increased packaging space due to protruding weld seams, which can lead to styling and functional issues, as well as potential engine damage from debris.

Innovation Solution

A silencer design featuring a tubular casing with two welded parts and an integrated third part that forms an annular cavity to contain weld flash, allowing for a clean production process without additional flash traps, and using spin welding to connect all parts in one process, ensuring the third part is positioned to prevent rattling noise and maintain acoustic tightness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If friction welding is used to join casing parts, then the casing can be securely connected, but welding flash is generated causing contamination and clearance problems

Engineering Contradiction:
Improvecasing connection strengthVSAvoidwelding flash contamination
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent utilizes the welding flash that would normally be harmful by directing it into the annular cavity where it serves as a seal between the casing parts and the acoustic insert. The flash material fills the gap and creates an effective seal, converting the contamination problem into a functional sealing solution.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The annular cavity acts as an intermediary space that captures and contains the welding flash, preventing it from contaminating the engine compartment while utilizing it for sealing purposes. The cavity mediates between the welding process and the external environment.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If flash traps are added to contain welding flash, then contamination is reduced, but the package space increases

Engineering Contradiction:
Improvewelding flash containmentVSAvoidsilencer package space
Core Design Contradiction:
Object-generated harmful factorsVSVolume of stationary object

Solution Approach 1:

The patent merges the flash trap function with the acoustic insert by integrating the annular cavity into the existing acoustic component structure. This eliminates the need for separate flash trap components, reducing overall package space while maintaining flash containment capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The acoustic insert serves multiple functions: it provides acoustic treatment for noise reduction and simultaneously acts as a flash trap through its annular cavity design. This multi-functionality eliminates the need for dedicated flash trap components.

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

3Object-generated harmful factors

If additional flash traps are installed to prevent debris, then contamination is reduced, but the device complexity increases

Engineering Contradiction:
Improvedebris preventionVSAvoidsilencer structure complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines the flash trap functionality with the acoustic insert structure, eliminating the need for separate debris prevention components. The annular cavity integrated into the acoustic insert serves both acoustic and debris containment functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The acoustic insert is designed to perform multiple functions simultaneously: acoustic noise reduction and debris containment through its annular cavity. This multi-functionality reduces overall device complexity by eliminating separate components.

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

4Object-generated harmful factors

If the third part is positioned to contain weld flash, then contamination is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveweld flash containmentVSAvoidthird part positioning accuracy
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The welding process itself generates the sealing material (flash) that fills the annular cavity, automatically creating the seal without requiring precise pre-positioning of the third part. The system uses the process byproduct to achieve the sealing function.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the state of the sealing interface from requiring precise geometric alignment to accepting a range of positions where the flash material can effectively seal. The sealing mechanism transitions from mechanical contact to material-based sealing that accommodates positioning variations.

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

The solution allows for a more efficient and clean production of silencers with reduced clearance issues and packaging space, preventing debris from interfering with gas flow and ensuring effective noise reduction without additional flash traps, while maintaining acoustic performance.

Implementation Method 1

using spin welding to connect all parts in one process

Methodology Applied
Scientific EffectSpin welding: Friction Welding

Implementation Method 2

a third part for the compensation of gas noise is positioned inside the tubular casing, wherein said third part is adopted and positioned in the casing in such a way that a weld flash which protrudes from an inner surface of said outer casing wall is kept inside an annular cavity formed at least by the third part and by the outer casing wall

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 3

a third part for the compensation of gas noise is positioned inside the tubular casing

Methodology Applied
Scientific EffectAcoustic compensation: Acoustic Absorption

Data Source

PatentEP3631188B1Silencer for the reduction of gas noise in an intake system of a combustion engine and a method for the production of such a silencer
Publication Date: 2024.03.06 MANN HUMMEL GMBH
  • EP3631188B1 patent drawingFigure 1
  • EP3631188B1 patent drawingFigure 2
  • EP3631188B1 patent drawingFigure 3

AI summary

A silencer for the reduction of gas noise in an intake system for acombustion engine, wherein the silencer comprises a tubular casing with a longitudinal casing axis and with at least a first and a second casing part welded together,wherein the two casing parts form an outer casing wall, wherein a weld seam connecting the first and the second casing part is part of the outer casing wall and wherein a third part for the compensation of gas noise is positioned inside the tubular casing, wherein said third part is adopted and positioned in the casing in such a way that a weld flash which protrudes from an inner surface of said outer casing wall is kept inside an annular cavity formed at least by the third part and by the outer casing wall,and a method for the production of such a silencer. Fig.