Outboard Motor Throttle Shift Interlock Mechanism
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Solution Overview
Problem
Outboard motors face issues with engine speed malfunctions and difficulty in starting due to high hydrocarbon concentrations in the cowl when the throttle is opened in neutral position, leading to potentially damaging high-speed shifts.
Innovation Solution
A regulating mechanism that restricts shift operations when the throttle opening exceeds a predetermined value in the neutral position, allowing unrestricted throttle operation while preventing shifts from the neutral state, and permitting throttle operation when the shift mechanism is in other states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the throttle opening is regulated when the shift position is neutral to prevent high engine speed malfunctions, then engine safety is improved, but the throttle opening cannot be increased sufficiently to overcome high HC concentration in the cowl during engine start-up
Solution Approach 1:
The invention segments the control functions by separating throttle operation from shift operation. The throttle mechanism can be operated independently without being coupled to the shift mechanism, allowing the throttle to be opened freely regardless of the shift position. This segmentation resolves the contradiction by enabling full throttle operation for engine start-up while maintaining separate control to prevent high-speed malfunctions in neutral gear.
2Device complexity
If the throttle and shift operations are coupled in conventional steering handles, then shift position control is simplified, but throttle and shift operations cannot be performed separately when needed
Solution Approach 1:
The invention applies segmentation by providing separate control mechanisms for throttle and shift operations. The throttle grip and shift lever are independently controllable, allowing operators to perform throttle operations without being constrained by shift position limitations. This enables versatile operation modes including separate throttle control for engine start-up while maintaining simplified steering handle configuration.
Solution Approach 2:
The steering handle is designed with multi-functionality to accommodate both separate throttle and shift operations. The universal design allows the handle to support different operational modes: coupled control for normal operation and separate control for special conditions like engine start-up, thereby resolving the contradiction between simplified configuration and operational adaptability.
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
Enhances engine start-up properties and prevents shift operations at high engine speeds by ensuring throttle and shift operations can be performed separately, improving safety and reliability.
Implementation Method 1
The cam member has a cam portion and rotates with a portion of the throttle mechanism. A plunger is operatively connected to the cam portion and moves linearly as the cam member rotates.
Data Source
AI summary
An outboard motor has a throttle actuator adapted to control an amount of intake air supplied to an engine, and a shift mechanism that controls shift operation between a neutral and at least a forward gear. The throttle actuator includes a member that is adapted to interfere with the shift mechanism so as to prevent shift actuation when the throttle is opened beyond a predetermined setting. As such, shift operation is prevented at high throttle openings, but throttle operation is still enabled.