Vehicle Misfire Shift Control for Transmission Torque Fluctuations
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Solution Overview
Problem
Existing vehicle systems face challenges in suppressing load fluctuations applied to automatic transmissions during engine misfires, leading to abrupt vehicle behavior and torque fluctuations, which existing technologies fail to adequately address.
Innovation Solution
A control apparatus is introduced that includes a damper with elastically deformable springs and a clutch between the internal combustion engine and automatic transmission, allowing for variable gear ratios to manage torque fluctuations. The apparatus determines engine misfires and executes shift-down actions to maintain gear ratios above a threshold, preventing excessive damper deformation and reducing load fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the connecting/disconnecting device is placed in its disconnecting state upon occurrence of misfire, then the fluctuation of load applied to the automatic transmission is suppressed, but the drive power transmitted from the internal combustion engine to the automatic transmission is momentarily reduced causing abrupt change of vehicle behavior
Solution Approach 1:
The damper is introduced as an intermediary device between the internal combustion engine and the automatic transmission. It absorbs torque fluctuations through elastic deformation of the damper spring, mediating the harmful load variations while keeping the connecting/disconnecting device engaged to maintain continuous power transmission and vehicle stability
Solution Approach 2:
The gear ratio of the automatic transmission is changed as a parameter to suppress torque fluctuations. By executing a shift-down action to increase the gear ratio above a higher threshold value, the system changes the transmission parameters to keep the damper spring within its elastic deformation range, preventing excessive load fluctuations on the automatic transmission
2Object-affected harmful factors
If the gear ratio is increased to suppress torque fluctuations, then the damper spring remains within elastic deformation limits, but the vehicle speed may be reduced
Solution Approach 1:
The system dynamically adjusts the gear ratio based on operating conditions and misfire detection. The control apparatus executes shift-down actions only when misfire occurs and the gear ratio is within the insufficient absorption region, making the gear ratio dynamic rather than fixed to optimize both torque fluctuation suppression and vehicle speed
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 solution effectively suppresses large torque fluctuations and load changes on the automatic transmission during misfires, stabilizing vehicle behavior without the need to release the clutch, thereby enhancing safety and performance.
Implementation Method 1
the damper includes a damper spring that is elastically deformable to a certain maximum limit, and is configured to absorb fluctuation of torque outputted from the internal combustion engine owing to elastic deformation of the damper spring
Data Source
AI summary
A control apparatus for a vehicle that includes an engine; a transmission; a damper and a clutch. The transmission has a gear ratio that is variable in a range including a torque-fluctuation insufficient absorption region in which a damper spring of the damper is elastically deformed to a certain maximum limit when a misfire occurs in the engine. The control apparatus includes: a misfire determination portion configured to determine occurrence of the misfire in the engine; and a misfire-case shift control portion configured, upon determination of the occurrence of the misfire in the engine by the misfire determination portion when the gear ratio of the transmission is in the torque-fluctuation insufficient absorption region, to cause the transmission to execute a shift-down action such that the gear ratio becomes higher than a higher threshold value of the torque-fluctuation insufficient absorption region.