Cause Identifying Device for Automatic Transmission Oil Temperature
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Solution Overview
Problem
In cooling systems of automatic transmissions, it is challenging to determine whether an elevated oil temperature is due to normal operation or an underlying abnormality, such as gear shifting device issues, when the oil temperature exceeds a predetermined threshold.
Innovation Solution
A cause identifying device that analyzes operational conditions, including transmission load, vehicle acceleration, and heat exchange dynamics to differentiate between normal high-load operations and potential abnormalities, using parameters like accelerator operation, vehicle speed, and refrigerant temperature to determine the cause of elevated oil temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the oil temperature threshold is used to determine abnormalities, then abnormality detection is simple, but false positives occur during normal high-load operations
Solution Approach 1:
The patent segments the abnormality determination process into multiple independent evaluation dimensions: transmission load conditions, vehicle acceleration, and oil temperature rise rate. Each dimension is evaluated separately using specific thresholds, and only when all dimensions indicate abnormality is a false alarm prevented. This segmentation allows the system to maintain simple threshold-based detection while improving reliability through multi-factor verification.
2Reliability
If multiple parameters are monitored to distinguish normal high-load operation from abnormalities, then detection accuracy improves, but system complexity increases
Solution Approach 1:
The patent implements dynamic threshold adjustment based on transmission load conditions. When the transmission is operating under high load (accelerator operation ≥ threshold, vehicle speed ≥ threshold), the system dynamically adjusts the oil temperature threshold to a higher value, allowing normal high-load temperature rises without triggering false alarms. This dynamic approach maintains high detection accuracy while avoiding the complexity of continuous multi-parameter monitoring, as the thresholds adapt automatically to operating conditions.
Solution Approach 2:
The patent changes the determination parameters based on transmission load state. Under high-load conditions, it uses elevated temperature thresholds and incorporates acceleration rate criteria. Under normal-load conditions, it uses standard temperature thresholds. This parameter change strategy allows accurate cause identification across different operating conditions while keeping the monitoring system relatively simple, as only the threshold values change rather than the fundamental monitoring architecture.
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
Effectively identifies the cause of elevated oil temperatures by distinguishing between normal high-load operations and potential abnormalities, enabling timely diagnosis and maintenance of gear shifting devices.
Implementation Method 1
a type of technique such as detecting an abnormality of an oil cooler which is provided in the vicinity of a radiator in a cooling system of an automatic transmission that cools a hydraulic oil (ATF) of the automatic transmission using the oil cooler
Data Source
AI summary
A cause identifying device performs: determining that an operation of a transmission with a predetermined high load is a cause of oil temperature of hydraulic oil having been equal to or higher than the predetermined temperature when predetermined conditions that the transmission has operated with the predetermined high load in a target period immediately before the oil temperature of the hydraulic oil has been equal to or higher than the predetermined temperature and a vehicle acceleration in the target period has been equal to or higher than a predetermined acceleration value are satisfied; and determining that occurrence of a predetermined abnormality associated with a gear shifting device is the cause of the oil temperature of the hydraulic oil having been equal to or higher than the predetermined temperature when the predetermined conditions are not satisfied.