Vehicle Lock-Up Clutch Control Device
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Solution Overview
Problem
The existing control devices for vehicles with lock-up clutches disengage the lock-up mechanism at a predetermined speed regardless of conditions, leading to inappropriate disengagement times, causing strong deceleration feelings and deteriorated fuel efficiency.
Innovation Solution
A control device that includes a lock-up control unit and a driving mode selection unit, allowing for different lock-up disengagement speeds based on driving modes, such as a first vehicle speed for normal mode and higher/lower second and third vehicle speeds for eco-mode with and without brake operation, respectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the lock-up clutch is disengaged at a predetermined vehicle speed regardless of conditions, then the control logic is simple, but the deceleration feeling becomes strong and fuel efficiency deteriorates
Solution Approach 1:
The patent applies dynamics by making the lock-up disengagement vehicle speed variable rather than fixed. The control device dynamically adjusts the disengagement speed based on driving conditions (coasting vs. brake deceleration) and driving modes (first vs. second mode), allowing the system to adapt to changing operational requirements and optimize fuel efficiency across different scenarios
Solution Approach 2:
The patent changes the parameter of lock-up disengagement vehicle speed based on different conditions. In coasting deceleration, the disengagement occurs at a higher speed in the second driving mode to maintain idle running feeling, while in brake deceleration, it occurs at a lower speed to improve fuel efficiency. This parameter adjustment resolves the contradiction between simple control and fuel efficiency
2Device complexity
If the lock-up clutch is disengaged at a predetermined vehicle speed regardless of conditions, then the control implementation is straightforward, but the running experience deteriorates due to strong deceleration feeling
Solution Approach 1:
The system dynamically adjusts the lock-up disengagement strategy based on the type of deceleration (coasting vs. brake) and selected driving mode. This dynamic adaptation allows the system to provide appropriate idle running feeling during coasting while maintaining simple control logic through clear conditional rules
Solution Approach 2:
The patent applies local quality by providing different lock-up disengagement characteristics for different deceleration scenarios. During coasting deceleration in the second driving mode, the lock-up disengages at a higher speed to provide idle running feeling, while during brake deceleration, it disengages at a lower speed. This localized optimization improves running experience without significantly complicating the overall control structure
3Loss of energy
If different lock-up disengagement speeds are set for different driving modes and brake operations, then fuel efficiency and running experience are improved, but the control system complexity increases
Solution Approach 1:
The patent segments the deceleration control into distinct scenarios: coasting deceleration and brake deceleration, each with further segmentation by driving mode (first and second modes). This segmentation allows optimized control for each scenario while maintaining manageable system complexity through clear conditional logic and separate speed thresholds (second vehicle speed for coasting, third vehicle speed for brake deceleration)
Data Source
AI summary
The lock-up control unit is configured to: in a case where the normal mode is selected, disengage the lock-up clutch when a vehicle speed decreases and reaches a first vehicle speed while the vehicle is traveling in a state where the lock-up clutch is engaged, in a case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a second vehicle speed in a brake operation OFF state while the vehicle is traveling in the state where the lock-up clutch is engaged, in the case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a third vehicle speed in a brake operation ON state while the vehicle is traveling in the state where the lock-up clutch is engaged, and set the third vehicle speed to a vehicle speed lower than the first vehicle speed, and set the second vehicle speed to a vehicle speed higher than the first vehicle speed.