Twin Clutch Transmission Shift Control Preventing Hammering
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Solution Overview
Problem
The existing twin clutch type automatic transmission systems experience hammering issues during pre-shift change operations due to the main shaft corresponding to the other side clutch rotating slightly, leading to mechanical play and sound generation.
Innovation Solution
A shift change controlling apparatus that sets a predetermined pre-shift change waiting time based on the speed of rotation and viscosity of the operating oil, ensuring appropriate pre-shift change timing by providing a suitable waiting period after a signal for removing pre-pressure is issued, and adjusting this time according to oil temperature and engine speed to prevent hammering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If pre-pressure is applied to the other side clutch to eliminate rotational play, then mechanical play between parts is reduced, but hammering occurs during pre-shift change operations
Solution Approach 1:
The system applies pre-pressure to the disengaged clutch in advance during ordinary traveling to eliminate rotational play between parts. This preliminary action prepares the clutch for upcoming shift operations by removing mechanical clearance, ensuring stable rotational alignment before the shift actually occurs.
Solution Approach 2:
The control system dynamically adjusts the pre-pressure application based on travel state detection. When pre-shift change is detected, the system removes pre-pressure from the disengaged clutch to prevent hammering during the shift operation. This dynamic adjustment allows the system to adapt between two states: applying pre-pressure for stability during normal travel, and removing it to prevent harmful hammering during shift operations.
2Speed
If pre-shift change is executed directly after pre-pressure application, then shift response time is improved, but hammering occurs due to main shaft rotation
Solution Approach 1:
The system dynamically controls the timing of pre-pressure removal based on detected shift operations. When pre-shift change is detected, the control unit removes pre-pressure from the disengaged clutch before executing the shift, preventing hammering while maintaining fast shift response through proper timing coordination.
Solution Approach 2:
The control unit detects the travel state and shift operation status to determine when to remove pre-pressure. This feedback mechanism ensures that pre-pressure is removed at the appropriate moment before pre-shift change execution, preventing hammering while maintaining efficient shift response timing.
3Object-generated harmful factors
If pre-pressure is removed immediately before pre-shift change, then hammering is prevented, but shift timing precision deteriorates
Solution Approach 1:
The control unit continuously monitors travel state and shift operation status to determine the optimal moment for pre-pressure removal. This feedback ensures precise timing coordination between pre-pressure removal and pre-shift change execution, maintaining shift timing precision while preventing hammering through accurately controlled pressure management.
Data Source
AI summary
The twin clutch-type transmission can include a hydraulic twin clutch including the first clutch and the second clutch disposed on main shafts. The shift change controlling apparatus is configured to control shift change operation to and adjacent speed change stage by alternately changing an engagement state of the first clutch and the second clutch. The shift change controlling apparatus can also execute a pre-shift change of supplying a pre-pressure on one of the first and second clutches, while another of the first and second clutches is engaged. The pre-pressure provides a pre-engagement of the unengaged clutch. First and second clutch actuators are configured to actuate the first and second clutches, respectively. When the pre-shift change is executed, the pre-pressure is applied for a predetermined period and then removed prior to a driving of a shift gear or actuating a shift change.