Boat Shift Actuator Control for Misalignment Prevention
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Solution Overview
Problem
Conventional boats face issues with shift motor overload and unsuccessful shifting when the engine is stopped, due to misalignment of dog clutches and gears, leading to large shift loads and potential damage from rust or salt crystals.
Innovation Solution
A boat with a remote control operation unit, a shift switching device, and a control means that stops the shifting operation when the engine is stopped and shifting is not completed within a certain time, shift speed is below a threshold, or electric current is above a certain value, preventing overloading and allowing for a smaller shifting force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If shift operation is continued when dogs are misaligned, then shift-in may eventually be achieved, but the shift motor, linkage, shift shaft, dog clutch, gears and other components will be overloaded and damaged
Solution Approach 1:
The control means continuously monitors shift operation status and provides feedback to determine whether shifting is progressing normally. When misalignment is detected (through lack of progress over time, abnormal current draw, or insufficient shift speed), the system automatically stops the shift operation to prevent component damage while maintaining the ability to retry later.
Solution Approach 2:
The control means performs preliminary assessment before completing the shift operation by monitoring whether the shift is progressing within expected parameters. If the shift operation does not show adequate progress within a predetermined time period, or if current draw exceeds thresholds indicating binding, the system preemptively stops the operation to avoid overloading components before damage occurs.
2Ease of operation
If shift operation is performed when engine is stopped and rust or salt crystals are present on shift link, then shift-in may be achieved, but large shift load will be applied to the shift motor
Solution Approach 1:
The control means monitors electric current consumption during shift operations and compares it against predetermined thresholds. When current draw exceeds the threshold for a predetermined time period, indicating excessive resistance from rust or salt crystals, the system automatically stops the shift operation to prevent excessive battery power consumption and potential motor damage.
Solution Approach 2:
The control means performs preliminary monitoring of shift operation parameters during engine-off conditions. By detecting abnormal current draw early in the shift sequence, the system can preemptively stop the operation before excessive energy is consumed, while still allowing normal shift operations to complete successfully.
3Reliability
If shift actuator operates continuously to overcome misalignment, then shift-in may be achieved, but the shifting operation will take excessive time and components will be overloaded
Solution Approach 1:
The control means monitors shift operation duration and progress continuously. When the shift operation exceeds a predetermined time period without achieving completion, or when shift speed falls below a threshold indicating binding or misalignment, the system automatically stops the operation to prevent excessive time loss and component overloading.
Solution Approach 2:
The control means establishes predetermined time thresholds and shift speed criteria before initiating shift operations. During operation, it continuously compares actual performance against these criteria and preemptively stops the shift if progress is insufficient, preventing both time loss and potential damage from prolonged operation.
4Ease of operation
If shift actuator uses high force to overcome rust and salt crystals on shift link, then shift-out may be achieved, but the shift motor will be overloaded
Solution Approach 1:
The control means monitors electric current consumption during shift-out operations and compares it against predetermined thresholds. When current draw exceeds the threshold for a predetermined time period, indicating excessive resistance from rust or salt crystals, the system automatically stops the shift operation to prevent overloading the shift motor while still allowing normal shift-out operations to complete.
Data Source
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AI summary
The present invention relates to a boat, comprising a boat propulsion unit (11); a shift switching device (23) for shifting between a drive mode and a neutral mode; a shift actuator (22) for operating the shift switching device; and a control means (64) for controlling operation of the shift actuator (22), wherein, when the control means (64) determines that a shifting operation during a stopped state of the engine (30) cannot be completed, the shift actuator (22) is controlled to stop the uncompleted shifting operation.