Dog Clutch Shift Control for Smooth Gear Engagement
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Solution Overview
Problem
In dog clutch type gear transmissions, smooth engagement of the dog with the next gear position is challenging during shifting, leading to inefficiencies and potential mechanical stress.
Innovation Solution
A transmission control device and method that includes a processing circuit to determine the engagement situation and execute separation control to disengage the dog from the current abutment surface and then initiate synchronous control to align the rotational speeds of the dog and transmission gears before moving to the next gear position, ensuring smooth engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the dog is moved directly from the current gear position to the next gear position without separation control, then the shifting speed is improved, but the dog may collide with the gear causing rough engagement and mechanical stress
Solution Approach 1:
The control device performs separation control before the dog reaches the next gear position. The output of the prime mover is adjusted to separate the dog from the abutment surface in advance, creating favorable conditions for smooth engagement at the target position
Solution Approach 2:
Synchronous control is performed before the dog enters the accommodation space at the next gear position. The rotational speeds of the dog and transmission gear are synchronized in advance to ensure smooth engagement when the dog enters the accommodation space
2Reliability
If separation control is performed to prevent dog collision, then the engagement smoothness is improved, but the shifting time increases
Solution Approach 1:
The control device dynamically adjusts the output of the prime mover during separation control to optimize the separation speed. This dynamic adjustment ensures the dog separates smoothly while minimizing the time required for the separation process
Solution Approach 2:
The synchronous control dynamically adjusts the rotational speeds of the dog and transmission gear to maintain optimal synchronization throughout the engagement process, reducing the overall time required for smooth engagement
3Reliability
If synchronous control is performed early to align rotational speeds, then the engagement smoothness is improved, but the control complexity increases
Solution Approach 1:
The control device uses feedback from sensors detecting the positions and rotational speeds of the dog and transmission gears to automatically adjust the prime mover output and synchronize speeds, simplifying the control process while ensuring smooth engagement
Solution Approach 2:
The control device automatically determines the start timing of synchronous control based on the position of the dog relative to the accommodation space, eliminating the need for complex external timing mechanisms and reducing control complexity
Data Source
AI summary
There are provided a transmission control device and a transmission control method that controls a prime mover in a system including the prime mover and a gear transmission. A processing circuitry of the transmission control device executes a process including: determining whether to fall into a predetermined situation at a time of acquiring a shift command; when it is determined as being the predetermined situation, starting a separation control that adjusts an output of the prime mover such that a dog is separated from an abutment surface against which the dog abuts at the time of acquiring the shift command; and after the separation control is completed and before the dog at the first transmission gear position moves out of an accommodation space at the first transmission gear position, starting a synchronous control relating to the dog and transmission gears.