Outboard Motor Exhaust Conduit and Adapter Plate Segmentation

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Solution Overview

Problem

The competition for design space in outboard motors, particularly beneath the engine, due to the placement and routing of exhaust conduits, cooling water jackets, engine mounts, oil pumps, and oil sumps, leads to compromised designs, increased costs, reduced performance, and inefficient use of space.

Innovation Solution

The exhaust conduit and adapter plate are designed as separate components, with the conduit featuring smooth curved sections and a cooling water jacket that extends around it, allowing for efficient routing and minimizing space usage, while the adapter plate is formed separately to avoid integration with the conduit, using die casting for cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the exhaust conduit is integrated into the adapter plate, then structural compactness is improved, but manufacturing complexity and cost increase due to requiring expensive casting methods and gasket seals

Engineering Contradiction:

Improvespace utilizationVSAvoidmanufacturing cost

Core Design Contradiction:

Volume of moving objectVSEase of manufacture

Solution Approach 1:

The exhaust conduit is separated from the adapter plate into a distinct component. The adapter plate is formed separately using cost-effective die casting, while the exhaust conduit is a separate piece that attaches to it, eliminating the need for complex integrated casting and gasket seals.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The exhaust conduit is extracted from the adapter plate structure. By removing this component from the integrated design, the adapter plate can be manufactured independently using simpler, less expensive die casting processes, while the conduit is produced as a separate part.

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If the exhaust conduit is routed back into alignment with the central plane, then exhaust gas can be discharged properly, but flow restriction increases due to sharp corners and the conduit being in the way of engine mounts

Engineering Contradiction:

Improveexhaust discharge alignmentVSAvoidflow restriction

Core Design Contradiction:

Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The exhaust conduit incorporates smooth curved sections instead of sharp corners to route the exhaust gas from the off-center cylinder block position back to the central plane alignment. These curved transitions minimize flow restriction and turbulence while achieving the required alignment for exhaust discharge.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Device complexity

If the exhaust conduit is placed through the center of the oil sump, then routing is simplified, but oil volume decreases and manufacturing cost increases due to longer sump formation

Engineering Contradiction:

Improverouting simplicityVSAvoidoil volume

Core Design Contradiction:

Device complexityVSQuantity of substance

Solution Approach 1:

The exhaust conduit is extracted from the oil sump area by being a separate component that attaches to the adapter plate. This allows the oil sump to be formed as a standard U-shaped structure with sufficient volume, without requiring the conduit to be routed through its center, thereby maintaining adequate oil capacity and simplifying manufacturing.

Inventive Principle:

Principle #2Taking out (Extraction)

4Volume of moving object

If multiple components share common design space beneath the engine, then compact outboard configuration is achieved, but design quality deteriorates with added cost and reduced performance

Engineering Contradiction:

Improveoverall sizeVSAvoiddesign quality

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The exhaust system components are segmented into separate, independently manufacturable parts. The adapter plate, exhaust conduit, cooling water jacket, and other components are designed as distinct elements that can be manufactured separately using optimized processes for each component, then assembled together. This segmentation allows each component to be designed and manufactured to its optimal specification without compromising overall compactness.

Inventive Principle:

Principle #1Segmentation

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 configuration reduces space wastage, minimizes flow restrictions, and allows for a more compact and cost-effective design, improving performance and reducing manufacturing complexity by avoiding the need for expensive casting methods and gasket seals.

Implementation Method 1

a cooling water jacket (30) that surrounds an outer circumference of the exhaust conduit (24)

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS8388393B1Outboard motors and exhaust systems for outboard motors

Publication Date: 2013.03.05 BRUNSWICK CORP

AI summary

An outboard motor includes an internal combustion engine, a driveshaft housing, a molded adapter plate connecting the internal combustion engine and the driveshaft housing; and an elongated exhaust conduit conveying hot exhaust gas from the internal combustion engine, the exhaust conduit extending from a first end portion located proximate to the internal combustion engine to a second end portion located proximate to the driveshaft housing. The exhaust conduit and adapter plate are separate components.