Motor Vehicle Transmission Gear Shifting With Parallel Disengagement
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Solution Overview
Problem
Existing motor vehicle transmission shifting methods, particularly dual-clutch transmissions, are time-consuming and complex due to the need for multiple actuations of shifting elements during gear disengagement and engagement, especially when activating winding gears, leading to inefficiencies in the shifting process.
Innovation Solution
The method involves actuating shifting elements simultaneously for disengagement and sequentially for engagement, using 'load-free' components to establish connections between transmission input shafts and drive shafts, allowing for partial parallel operation of shifting elements to reduce the time required for gear changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple shift elements are actuated sequentially during gear engagement, then the transmission can be shifted reliably, but the shifting time increases and productivity decreases
Solution Approach 1:
The patent applies preliminary action by pre-positioning the target gear on the output shaft before the shifting process begins. The synchronizer is prepared in advance to match speeds, and the gear is already aligned on the output shaft, allowing for faster and more reliable engagement without requiring sequential actuation of multiple shift elements during the actual shifting moment.
2Productivity
If multiple shift elements are actuated simultaneously during disengagement, then the shifting process is accelerated, but the control complexity increases
Solution Approach 1:
The patent extracts the complexity of simultaneous multi-element actuation by focusing on a single primary shift element that controls the synchronizer. The disengagement process is simplified to primarily involve this one shift element, while other components follow automatically, thereby maintaining high shifting speed without proportionally increasing control complexity.
3Device complexity
If sequential actuation of shift elements is used during engagement, then the control complexity is reduced, but the shifting time increases leading to loss of time
Solution Approach 1:
The patent ensures continuity of useful action by maintaining constant rotational motion of the output shaft throughout the shifting process. The target gear remains continuously positioned on the output shaft, and the synchronizer continuously matches speeds, eliminating idle time and ensuring that the engagement process flows without interruption, thereby reducing overall shifting time despite using controlled sequential actuation.
4Productivity
If parallel operation of multiple shift elements is implemented, then the shifting process is accelerated, but the manufacturing precision requirements increase
Solution Approach 1:
The patent introduces the synchronizer as an intermediary mechanism that mediates between the input shaft and the target gear during parallel shifting operations. The synchronizer absorbs and manages the speed differences and torque variations that arise during parallel actuation of multiple shift elements, thereby protecting the system from excessive precision requirements while enabling faster shifting.
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
This approach accelerates the shifting process by eliminating the need for simultaneous actuation of all shifting elements during disengagement and optimizing gear engagement through controlled sequential and parallel operations, thereby simplifying the circuitry and control complexity.
Implementation Method 1
The first transmission input shaft is connected to a drive motor via a first friction clutch, and the second transmission input shaft is connected to a second friction clutch
Data Source
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AI summary
The invention relates to a method for shifting gears in a motor vehicle transmission (2), wherein a current gear is disengaged, a plurality of shifting elements (S1 to S6) being actuated during the disengagement. In order to improve the method for shifting gears in the motor vehicle transmission (2), a plurality of the shifting elements (S1 to S6) is actuated at least partly simultaneously during the disengagement.