Powertrain Housing Insert Damping via Non-Bonded Casting

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Solution Overview

Problem

Existing methods for reducing vehicle engine noise transmitted to the passenger compartment are inadequate, as they primarily focus on noise reduction rather than addressing the source of the noise, and there is a need for alternative effective noise-damping solutions.

Innovation Solution

A method involving the casting of steel or aluminum inserts into powertrain housing components with a coating to prevent bonding, allowing a non-bonded interfacial boundary for damping, while using tabs for support and bonding with the cast material to prevent corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If polymer coatings or sound absorbing barriers are used to reduce engine noise, then noise transmission to the passenger compartment is reduced, but the source of the noise is not addressed and additional components are required

Engineering Contradiction:

Improvenoise transmissionVSAvoidnumber of additional components

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The noise-damping insert is integrated directly into the powertrain housing structure, combining the housing's structural function with the noise-damping function. This eliminates the need for separate polymer coatings or sound absorbing barriers, reducing component complexity while maintaining noise reduction effectiveness.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The noise-damping capability is extracted as a separate insert component that can be independently manufactured and then integrated into the housing. This allows the noise-damping function to be added without redesigning the entire housing structure, simplifying the implementation process.

Inventive Principle:

Principle #2Taking out (Extraction)

2Object-affected harmful factors

If an insert is cast into the powertrain housing, then a proper interfacial boundary is created for noise damping, but bonding between the insert and casting material may occur which would eliminate the damping effect

Engineering Contradiction:

Improvenoise dampingVSAvoidinterfacial boundary integrity

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

A coating is applied to the insert surface as an intermediary layer between the insert material and the casting material. This coating prevents unwanted bonding while allowing the insert to be securely positioned, maintaining the non-bonded interfacial boundary necessary for effective noise damping.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The surface properties of the insert are modified through coating application, changing the chemical and physical parameters of the insert surface. This creates a controlled interface that prevents bonding while maintaining structural integrity and positioning accuracy during the casting process.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If tabs are used to support the insert during casting, then positioning accuracy is improved, but bonding between tabs and casting material may allow corrosion elements to reach the interfacial boundary

Engineering Contradiction:

Improveinsert positioningVSAvoidcorrosion protection

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The coating is applied selectively to different regions of the insert: removed or not applied to tabs to allow bonding for positioning support, while maintained on the main body surfaces to prevent bonding and protect the interfacial boundary. This local differentiation of coating presence provides both positioning accuracy and corrosion protection.

Inventive Principle:

Principle #3Local quality

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 approach effectively reduces vehicle noise by creating a proper interfacial boundary for damping and prevents corrosion, making it suitable for powertrain components and other noise-producing structures.

Implementation Method 1

the insert is provided with a coating to prevent bonding between the insert and the casting material

Methodology Applied

Scientific EffectNon-bonding interface:

Implementation Method 2

U.S. patent application Ser. No. 10/961,813, filed Oct. 8, 2004, commonly assigned with the present application, teaches Coulomb friction damped disc brake rotor configurations having an insert within the rotor to provide improved damping

Methodology Applied

Scientific EffectCoulomb friction damping: Coulomb Damping

Implementation Method 3

With a portion of each tab bonded with the wall, corrosion-causing exterior elements are prevented from reaching the interfacial boundary

Methodology Applied

Scientific EffectCorrosion prevention:

Data Source

PatentUS7644750B2Method of casting components with inserts for noise reduction

Publication Date: 2010.01.12 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

The invention provides a method for manufacturing a powertrain component enclosure member, including the steps of: (A) positioning at least one insert into a mold, wherein the insert is provided with a coating to prevent bonding between the insert and the casting material; and (B) casting a wall of the powertrain component enclosure member in the mold around the insert such that a major portion of the insert is substantially non-bonded with the casting material to provide a proper interfacial boundary with the casting material for damping.