Outboard Motor Shift Control Retarding Ignition to Prevent Shock
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Solution Overview
Problem
Existing shift motion control devices for outboard motors often cause engine output instability and shock during shifting by inadvertently reducing engine speed even when shifting is not performed, leading to unstable engine output and potential stalling.
Innovation Solution
A shift motion control device that includes a lever position detection system, shift-in operation determination, engine output control, and a shift actuator engagement mechanism, which reduces engine speed only when a shift-in operation is confirmed, using ignition timing retardation and output reduction control to prevent shocks and maintain stable engine output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If engine speed is reduced when the shift lever is moved out of the neutral position, then the shock generated at shift-in is prevented, but the engine output becomes unstable
Solution Approach 1:
The system performs preliminary detection of shift-in operation intent through lever position detection before actually reducing engine output. The control device monitors whether the lever has reached the shift-in position, and only then executes engine output reduction, ensuring the action is taken at the appropriate moment rather than prematurely
Solution Approach 2:
The system continuously monitors lever position through the lever position detection device and uses this feedback to control when engine output reduction is executed. The shift-in operation determination device processes detection signals to determine whether shift-in is intended, and this feedback loop ensures engine output is reduced only when actual shift-in operation is confirmed, preventing unnecessary output fluctuations
2Object-affected harmful factors
If engine speed is reduced during shift-in operation, then the shock is prevented, but the engine torque may be excessively reduced causing engine stall
Solution Approach 1:
The system changes engine parameters (ignition timing and/or fuel injection amount) to reduce engine output smoothly during shift-in operation. By adjusting these parameters rather than abruptly reducing engine speed, the system prevents shock while maintaining sufficient torque to avoid engine stall
Solution Approach 2:
The system dynamically adjusts engine output based on the shift-in operation determination. The engine output control device continuously monitors the shifting state and adjusts output in real-time, creating a dynamic response that prevents shock during engagement while maintaining stability throughout the transition
3Speed
If the dog clutch is engaged with the gear during high engine output, then shifting is faster, but a shock occurs during shift-in
Solution Approach 1:
The system executes engine output reduction in advance of the actual clutch engagement. The control device detects shift-in operation intent and reduces engine output before the dog clutch fully engages with the gear, so that when engagement occurs, the reduced output minimizes shock while the pre-positioned components enable quick engagement
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
The device effectively prevents engine shocks during shifting while maintaining stable engine output by ensuring engine speed reduction only occurs during confirmed shift-in operations, thereby preventing engine stalling and output instability.
Implementation Method 1
the engine output control device is an ignition timing control device arranged to retard ignition timing of the engine
Data Source
AI summary
A shift-in operation determination device determines a shift-in operation based on a signal in accordance with an operation of a remote control lever. An ignition timing operation device retards an ignition timing of an engine based on a determination result of the shift-in operation by the shift-in operation determination device. A shift-in command device engages a shift actuator and a dog clutch with either of a forward traveling bevel gear or a rearward traveling bevel gear in a state where the ignition timing of the engine is retarded. The shift-in operation determination device works to prevent a shock which occurs at a shift-in while maintaining a stable engine output in an outboard motor.