Lockup Clutch Engagement Control Strategy
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Solution Overview
Problem
Existing vehicle control systems face challenges in smoothly transitioning from lockup clutch release to engagement, leading to engagement shocks and prolonged engagement times, which deteriorate vehicle running performance.
Innovation Solution
A control apparatus and method that performs lockup clutch engagement control in a sequence of fast fill, constant-pressure standby, and command pressure raising, starting engagement control from the later stage in the sequence when the command pressure is sufficient, to avoid shocks and improve transition efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If lockup clutch engagement control is started from packing after waiting for the end of release control, then engagement shock is restrained, but engagement time becomes relatively long
Solution Approach 1:
The patent applies preliminary action by detecting whether the lockup clutch is in a released state before starting engagement control. When the clutch is already released during release control, the system skips the packing phase and directly starts engagement control, utilizing the pre-existing released state to reduce engagement time without causing shock
2Object-affected harmful factors
If lockup clutch engagement control is started from fast fill control to narrow pack clearance, then engagement shock is restrained, but vehicle running performance deteriorates
Solution Approach 1:
The patent applies dynamics by making the engagement control start point variable based on the detected release control state. When the clutch is already released, the system dynamically switches to start from command pressure raising control instead of fast fill control, adapting the control strategy to current conditions to improve response speed while maintaining shock restraint
3Productivity
If lockup clutch engagement control is started from command pressure raising control when command pressure rises during release control, then vehicle running performance is improved, but engagement shock may occur
Solution Approach 1:
The patent applies feedback by continuously detecting the release control state and using this information to determine the appropriate start point for engagement control. The ECU adjusts the engagement control strategy based on real-time feedback about whether the clutch is in a released state, optimizing both performance and shock prevention
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 effectively prevents engagement shocks and enhances vehicle running performance by optimizing the transition process, ensuring quicker and smoother lockup clutch engagement.
Implementation Method 1
a lockup clutch that directly couples an input member and an output member of the fluid coupling to each other through the supply of a control oil pressure into a control oil chamber
Data Source
AI summary
An electronic control unit performs lockup clutch engagement control in the sequence of fast fill control, constant-pressure standby control and command pressure raising control, and starts the lockup clutch engagement control from that one of the fast fill control and the command pressure raising control which is later in sequence than the other, as a command pressure for a control oil pressure at a transition time point for making a transition to the lockup clutch engagement control rises, in making the transition to the lockup clutch engagement control during the lockup clutch release control. Therefore, when the command pressure for the control oil pressure is equal to or higher than a predetermined value that is needed to carry out packing for narrowing a pack clearance of a lockup clutch, the lockup clutch engagement control is started from the command pressure raising control.