Vehicle Hydraulic Circuit Decoupling for Stable Clutch Control
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Solution Overview
Problem
Hybrid electric vehicles require a sophisticated hydraulic control system to manage power between engines and motors efficiently, ensuring stable clutch engagement and shifting quality across various working modes, which existing systems struggle to achieve due to complex control requirements and high flow demands for cooling and lubrication.
Innovation Solution
A vehicle hydraulic control system comprising a high-pressure control oil circuit, a low-pressure cooling and lubricating oil circuit, a mechanical pump, an electronic pump, and a high-low pressure decoupling valve, connected to a transmission controller, allowing dynamic adjustment of oil flow and pressure to meet different working modes, reducing the load on the electronic pump and improving efficiency and service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single hydraulic control system is used for both clutch control and cooling/lubrication, then the system structure is simplified, but the control precision and response stability for clutch engagement deteriorate due to conflicting flow demands
Solution Approach 1:
The hydraulic control system is segmented into two independent circuits: a high-pressure control oil circuit for clutch engagement control and a low-pressure cooling and lubricating oil circuit for motor cooling. This segmentation allows each circuit to be optimized independently, ensuring stable clutch control while meeting cooling demands without mutual interference.
Solution Approach 2:
A high-low pressure decoupling valve is introduced as an intermediary component to connect and decouple the high-pressure and low-pressure circuits. This valve enables flexible switching between coupled and decoupled states, allowing the system to adapt to different working conditions while maintaining independent control over each circuit's pressure and flow characteristics.
2Speed
If the electronic pump supplies oil to both high-pressure control and low-pressure cooling circuits simultaneously, then the system responds quickly to clutch engagement, but the electronic pump load increases excessively affecting its service life
Solution Approach 1:
The system dynamically switches the connection state of the high-low pressure decoupling valve based on working conditions. During clutch engagement, the valve couples the circuits allowing the electronic pump to supply high-pressure oil quickly. During normal operation, the valve decouples the circuits allowing the mechanical pump to supply the low-pressure cooling circuit, reducing the electronic pump's continuous load and extending its service life.
Solution Approach 2:
The mechanical pump is pre-configured to supply the low-pressure cooling and lubricating oil circuit directly, so that during normal operation the electronic pump does not need to continuously supply oil to the cooling circuit. This preliminary arrangement reduces the electronic pump's workload during non-clutch-engagement periods.
3Quantity of substance
If high flow rate is provided for motor cooling and lubrication, then the cooling and lubrication effectiveness is improved, but the clutch engagement control precision deteriorates due to pressure fluctuations
Solution Approach 1:
By segmenting the hydraulic system into separate high-pressure and low-pressure circuits, the patent enables independent optimization of flow rates for each function. The low-pressure circuit can provide high flow rates for effective cooling and lubrication without causing pressure fluctuations that would affect the precision of the high-pressure clutch engagement control circuit.
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
The system enhances the stability and efficiency of clutch control and shifting quality by dynamically adjusting oil flow and pressure, ensuring hydraulic requirements are met across various modes, thereby improving the overall performance and reliability of the vehicle hydraulic control system.
Implementation Method 1
a main pressure regulating mechanical valve configured to guide a flow output by the electronic pump and/or the mechanical pump communicated with the high-pressure control oil circuit to the low-pressure cooling and lubricating oil circuit according to a control of the main pressure regulating pilot solenoid valve
Implementation Method 2
an electronic pump communicated with the high-pressure control oil circuit or the low-pressure cooling and lubricating oil circuit through the high-low pressure decoupling valve; wherein when the high-low pressure decoupling valve is in a coupled state, the electronic pump is communicated with the high-pressure control oil circuit, and when the high-low pressure decoupling valve is in a decoupled state, the electronic pump is communicated with the low-pressure cooling and lubricating oil circuit
Data Source
AI summary
A vehicle hydraulic control system comprises a high-low pressure decoupling valve, a high-pressure control oil circuit including a main pressure regulating pilot solenoid valve connected to a transmission controller and used for regulating the main oil pressure according to the instructions of the transmission controller and a main pressure regulating mechanical valve, a low-pressure cooling and lubricating oil circuit, a mechanical pump communication with the high-pressure control oil circuit, and an electronic pump is in communication with the high-pressure control oil circuit or the low-pressure cooling and lubricating oil circuit by means of the high-low pressure decoupling valve. The main pressure regulating mechanical valve is used for guiding the flow output by the electronic pump and/or the mechanical pump in communication with the high-pressure control oil circuit to the low-pressure cooling and lubricating oil circuit according to the control of the main pressure regulating pilot solenoid valve.