Outboard Motor Cowl Dynamics for Tilt Interference

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Solution Overview

Problem

The existing design of outboard motors limits the reduction in size of the motor well due to interference with the rear wall when the motor is tilted up, which restricts the expansion of deck space.

Innovation Solution

An outboard motor with a tilt mechanism that includes a movable cowl portion, which pivots from a tilt-down to a tilt-up position, allowing the cowl to shrink and reduce its contour, thereby enabling a smaller motor well size and expanded deck space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the rear wall is shifted rearward to expand deck space, then the deck space is expanded, but the outboard motor interferes with the rear wall when tilted up

Engineering Contradiction:

Improvedeck spaceVSAvoidmotor tilt operation

Core Design Contradiction:

Area of stationary objectVSEase of operation

Solution Approach 1:

The cowl is divided into a fixed portion and a movable portion that can change position dynamically. When the motor tilts up, the movable portion moves to a first position that clears the rear wall, avoiding interference. When the motor is in the tilt-down position, the movable portion returns to a second position that maintains the original contour for normal operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The cowl is segmented into a fixed portion and a movable portion. The movable portion can be independently actuated to change the overall contour of the cowl, allowing the motor housing to adapt its shape based on the tilt position without affecting the entire structure.

Inventive Principle:

Principle #1Segmentation

2Volume of stationary object

If the motor well size is reduced to expand deck space, then the motor well size is reduced, but the outboard motor cannot be tilted up due to interference with the rear wall

Engineering Contradiction:

Improvemotor well sizeVSAvoidmotor position adaptability

Core Design Contradiction:

Volume of stationary objectVSAdaptability or versatility

Solution Approach 1:

The movable portion of the cowl dynamically adjusts its position based on the motor's tilt angle. During tilting operation, it moves to provide clearance from the rear wall, enabling the motor to reach the tilt-up position even in a reduced motor well. When not tilting, it returns to maintain the compact contour.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The contour parameters of the cowl are changed dynamically through the movement of the movable portion. This allows the motor housing to adapt its dimensional parameters (specifically the distance to the rear wall) based on operational requirements, enabling both compact storage and full tilt range in a reduced motor well.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS9994295B2Outboard motor

Publication Date: 2018.06.12 YAMAHA MOTOR CO LTD

AI summary

An outboard motor includes an engine, a cowl, and a tilt mechanism. The cowl accommodates the engine. The tilt mechanism pivots the cowl from a tilt-down position to a tilt-up position about a horizontal tilt axis. The cowl includes a movable portion that moves from a normal position to a contracted position to reduce a contour of the cowl when the cowl is pivoted from the tilt-down position to the tilt-up position by the tilt mechanism.