CVT Electric Oil Pump Control During High Vehicle Deceleration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle control systems, such as those described in Patent Document 1, experience delays in vehicle acceleration due to air suction by the electric oil pump during significant vehicle deceleration, leading to driver discomfort.
Innovation Solution
A control device and method for a vehicle that includes a transmission with both a mechanical oil pump and an electric oil pump. The system controls the electric motor driving the electric oil pump to supply hydraulic pressure to the transmission only when the vehicle's deceleration is within a prescribed range, and restricts this supply when deceleration exceeds a second prescribed deceleration, preventing air suction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric oil pump is driven to supply hydraulic pressure during vehicle deceleration, then the transmission receives adequate oil supply, but air is suctioned into the transmission causing acceleration delay
Solution Approach 1:
The patent applies dynamics by making the oil pump operation state changeable based on vehicle conditions. The control device dynamically adjusts whether the oil pump operates during deceleration based on detected deceleration magnitude, transitioning between operational states (operating vs. non-operating) to optimize both oil supply reliability and acceleration response time
Solution Approach 2:
The patent changes the operational parameter of the oil pump based on deceleration parameter thresholds. When deceleration exceeds the threshold, the pump operation is restricted; when deceleration is within the threshold, the pump operates. This parameter-based control resolves the contradiction by adapting pump operation to actual vehicle deceleration conditions
2Stress or pressure
If the electric oil pump operates at high deceleration rates, then hydraulic pressure is maintained in the transmission, but air enters the system causing performance degradation
Solution Approach 1:
The patent applies preliminary anti-action by preemptively restricting oil pump operation when high deceleration is detected. The control device detects deceleration magnitude in advance and prevents pump operation before air suction can occur, thereby preventing the harmful effect rather than correcting it after occurrence
Solution Approach 2:
The patent converts the potentially harmful situation of pump operation during deceleration into a beneficial control strategy. By using deceleration detection as the basis for controlling pump operation, the system transforms what could be a harmful condition (air suction) into a controlled operational parameter that ensures reliable oil supply when safe and prevents harm when deceleration is high
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 reduces the influence of air suction on the transmission, allowing for smoother acceleration and reducing driver discomfort by ensuring adequate oil supply during deceleration and preventing air suction at high deceleration rates.
Implementation Method 1
supply a hydraulic pressure from the second oil pump to the transmission
Data Source
AI summary
A control device for a vehicle, the vehicle including a belt continuously variable transmission including a mechanical oil pump driven by an engine and an electric oil pump driven by an electric motor, the engine being configured to drive a drive wheel, in which when a rotation speed of the engine is less than or equal to a prescribed rotation speed as the vehicle decelerates, driving of the electric motor is controlled to supply a hydraulic pressure from the electric oil pump to the belt continuously variable transmission, and when the deceleration of the vehicle exceeds a prescribed deceleration, the driving of the electric motor is restricted not to supply the hydraulic pressure from the electric oil pump to the belt continuously variable transmission.