Automatic Transmission Controller Preliminary Shifting Control
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Solution Overview
Problem
Existing automatic transmission assemblies fail to simultaneously shorten gear shifting times for both upshifting and downshifting, and do not effectively control gear shifting during a partially neutral position, leading to increased shifting times and shocks.
Innovation Solution
An automatic transmission assembly with a twin clutch system and a controller that performs preliminary shifting actions for both upshifting and downshifting, utilizing hydraulic pressure and an electric motor to control the shift drum, and incorporating a partially neutral position to reduce angular speed and shifting shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If gear shifting is performed without considering partially neutral position, then shifting operation is simple, but shifting shocks increase and reliability decreases
Solution Approach 1:
The controller performs preliminary shifting control in advance, determining the preliminary shifting position based on the current gear position before the actual gear change occurs. This preliminary action allows the system to prepare for the upcoming gear change, reducing shocks and improving reliability without significantly increasing operational complexity.
Solution Approach 2:
The system incorporates feedback by detecting the current gear position and using this information to determine the appropriate preliminary shifting position. The controller continuously monitors the gear position and adjusts the preliminary shifting control accordingly, ensuring reliable gear changes while managing system complexity.
2Speed
If shift drum angular speed is not reduced during gear shifting, then shifting operation is fast, but shifting shocks increase
Solution Approach 1:
The controller performs preliminary shifting control in advance, preparing the shift drum for the upcoming gear change by positioning it at the preliminary shifting position. This preliminary action allows for controlled reduction of angular speed at the appropriate moment, minimizing shifting shocks while maintaining overall shifting speed efficiency.
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 solution significantly reduces gear shifting times for both upshifting and downshifting while minimizing shifting shocks, ensuring reliable and efficient gear changes even during partial neutral positions.
Implementation Method 1
twin clutch assembly having first and second clutches disposed on the main shaft or the auxiliary shaft for selectively transmitting rotary drive power between the crankshaft and the transmission unit
Implementation Method 2
controller for changing the angular position of a shift drum for actuating a shift fork
Data Source
AI summary
An automatic transmission assembly having a transmission unit including a plurality of gear pairs, a shift drum, a pair of clutches; and a controller. The controller performs a preliminary upshifting action in advance for angularly moving the shift drum depending on a next gear position in an upshifting direction while rotary drive power is being maintained at a given gear position, and when an upshifting command is output, the controller engages one of the clutches simultaneously with the command. When a downshifting command is output, the controller performs a preliminary downshifting action in advance based on the downshifting command. The partially neutral positions are provided between predetermined angular positions on the shift drum for temporarily reducing the angular speed of the shift drum when the shift drum is being angularly rotated.