Outboard Motor Intake Manifold Layout Inversion

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Solution Overview

Problem

The existing configuration of outboard motors with intake manifolds extending forward from cylinder heads and a throttle body in front of the engine results in a large front size, which can interfere with the vessel body of a watercraft, necessitating a heavier structural attachment to prevent interference.

Innovation Solution

Reconfiguring the outboard motor to have the intake manifold extend backward from the cylinder and the throttle body positioned backward of the head cover, reducing the front size and eliminating the need for rearward displacement, thus preventing interference and minimizing weight increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the throttle body is disposed in front of the engine with intake manifolds extending forward from cylinder heads, then the engine can be configured with a conventional layout, but the front part of the outboard motor becomes large in size and interferes with the vessel body during tilting

Engineering Contradiction:

Improveconventional engine layoutVSAvoidfront part size

Core Design Contradiction:

Ease of operationVSLength of stationary object

Solution Approach 1:

The patent inverts the conventional layout by positioning the throttle body backward of the head cover instead of in front of the engine, and extending intake manifolds backward from the cylinder heads rather than forward. This inversion relocates the throttle body to a position that does not interfere with the vessel body during tilting operations, resolving the contradiction between conventional layout and front part size.

Inventive Principle:

Principle #13The other way round (Inversion)

2Length of stationary object

If the outboard motor is set backward from the vessel body to prevent interference, then the front part does not interfere with the vessel body, but the structural attachment must be strengthened which increases weight

Engineering Contradiction:

Improvefront part sizeVSAvoidoutboard motor weight

Core Design Contradiction:

Length of stationary objectVSWeight of moving object

Solution Approach 1:

Instead of displacing the entire outboard motor backward to avoid interference, the patent inverts the internal component layout to relocate the throttle body backward of the head cover. This internal reconfiguration achieves the same interference prevention without requiring external displacement or strengthened attachment structures, thereby avoiding weight increase.

Inventive Principle:

Principle #13The other way round (Inversion)

3Device complexity

If the throttle body is disposed in front of the engine, then the configuration is simple, but the front part size becomes large causing interference with vessel body

Engineering Contradiction:

Improveconfiguration simplicityVSAvoidfront part size

Core Design Contradiction:

Device complexityVSLength of stationary object

Solution Approach 1:

The patent applies inversion by reversing the positional relationship of the throttle body relative to the engine components. The throttle body is positioned backward of the head cover rather than in front of the engine, maintaining configuration simplicity while reducing front part size to eliminate interference with the vessel body.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS10920664B2Outboard motor

Publication Date: 2021.02.16 YAMAHA MOTOR CO LTD

AI summary

An intake manifold is connected to a cylinder of an engine, and extends backward from the cylinder. A throttle body is attached to the intake manifold. As seen in a plan view of an outboard motor, the throttle body is disposed backward of a head cover, while being disposed inward of a lateral end of the intake manifold in a right-and-left direction of the outboard motor.