Vehicle Cooling Pump Abnormality Detection
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Solution Overview
Problem
In vehicle cooling systems, the electric oil pump is often incorrectly determined as abnormal due to temperature discrepancies between the oil suction part and the oil temperature sensor, leading to erroneous determinations, especially when the sensor is thermally affected by the cooling target and the pump experiences prolonged stop times.
Innovation Solution
A vehicle cooling system that includes an oil circulation circuit, an oil temperature sensor, and a control device with a pump abnormality determination portion, which outputs a rotation command to the electric oil pump based on the operation stop time and oil temperature detection values, reducing erroneous abnormality determinations by allowing heat dissipation to align sensor readings with actual suction part temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the oil temperature sensor is disposed near the cooling target to detect temperature, then the cooling control can be improved, but the temperature detection accuracy at the oil suction part deteriorates due to thermal influence from the cooling target
Solution Approach 1:
The control device determines abnormality only after a predetermined time has elapsed since the pump stopped operating. This preliminary waiting period allows the oil temperature at the suction part to stabilize and align with the sensor detection value, eliminating temperature differences before abnormality determination occurs.
Solution Approach 2:
The system changes the timing parameter for abnormality determination by introducing a time delay condition. The pump abnormality determination is performed only when the operation stop time exceeds a predetermined threshold, thereby changing the temporal parameter to ensure accurate temperature conditions for determination.
2Speed
If the pump abnormality determination is performed immediately when the rotation command is output, then the responsiveness is improved, but erroneous abnormality determination occurs due to temperature difference between sensor and suction part
Solution Approach 1:
The system changes the temporal parameter for abnormality determination by introducing a time delay condition. The pump abnormality determination is performed only when the operation stop time exceeds a predetermined threshold, thereby ensuring accurate temperature conditions while maintaining systematic responsiveness.
Solution Approach 2:
The control device uses feedback from the operation stop time measurement to control the abnormality determination timing. By monitoring how long the pump has been stopped and comparing it against the predetermined threshold, the system feedback-controls when to perform determination, ensuring both accuracy and responsiveness.
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 enhances the accuracy and reliability of abnormality determination for the electric oil pump without increasing the number of parts, reducing noise, vibration, and electric power consumption by minimizing unnecessary abnormality checks.
Implementation Method 1
an oil circulation circuit in which a cooling oil is circulated by an electric oil pump to cool a predetermined cooling target with the cooling oil
Implementation Method 2
an oil temperature sensor detecting an oil temperature that is a temperature of the cooling oil
Data Source
AI summary
A vehicle cooling system comprises an oil circulation circuit in which a cooling oil is circulated by an electric oil pump to cool a predetermined cooling target with the cooling oil; an oil temperature sensor detecting an oil temperature that is a temperature of the cooling oil; and a control device including a cooling control portion outputting a rotation command for operating the electric oil pump so as to cool the cooling target. The control device includes a pump abnormality determination portion outputting the rotation command to the electric oil pump to determine a presence/absence of abnormality based on a rotation state of the electric oil pump when an operation stop time of the vehicle is longer than a predefined determination permission time and an oil temperature detection value detected by the oil temperature sensor is higher than a predefined determination permission temperature.