Multi-Function Solenoid Valve for Automatic Transmission Pressure Control
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Solution Overview
Problem
Existing fluid pressure control devices for automatic transmissions are limited by size and weight due to the need for multiple control valves, each serving a specific function, and face challenges with leakage at high temperatures and creep phenomena at low temperatures.
Innovation Solution
A fluid pressure control device with a single control valve that integrates multiple functions, including switching a two-way clutch, parking lock mechanism, hydraulic pressure supply, line pressure adjustment, and fail-safe line pressure boosting, utilizing a solenoid valve and a transmission control device ECU to manage these functions efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple control valves are provided for each function, then each function can be controlled reliably, but the size and weight of the fluid pressure control device increase
Solution Approach 1:
The patent applies multi-functionality by enabling a single control valve to perform multiple functions through software control. The control valve can switch between controlling the parking lock mechanism, two-way clutch, and line pressure adjustment based on activation signals from the control unit, eliminating the need for separate dedicated valves for each function while maintaining reliable control.
2Reliability
If multiple control valves are provided for each function, then each function can be controlled reliably, but the size of the fluid pressure control device increases
Solution Approach 1:
The control valve is designed as a universal component that can be activated for different functions based on control signals. By sharing a single control valve across multiple functions (parking lock, two-way clutch, line pressure), the device footprint is significantly reduced compared to having separate dedicated valves for each function.
3Weight of stationary object
If a single control valve is used for multiple functions, then the size and weight of the device are reduced, but the complexity of controlling the valve increases
Solution Approach 1:
The patent replaces mechanical complexity with electronic/software control. Instead of having complex mechanical linkages or separate physical valves for each function, the system uses a control unit that sends activation signals to a single control valve, managing multiple functions through electronic control logic that simplifies the overall system architecture.
4Reliability
If hydraulic pressure is increased to prevent leakage at high temperature, then sealing performance improves, but the risk of creep phenomenon at low temperature increases
Solution Approach 1:
The system dynamically adjusts hydraulic pressure based on operating conditions. The control unit monitors temperature and activates the line pressure adjustment function when high temperature is detected, while maintaining normal pressure at low temperatures. This dynamic adaptation prevents both high-temperature leakage and low-temperature creep phenomena.
Solution Approach 2:
The patent changes the hydraulic pressure parameter based on temperature conditions. At high temperatures, the control unit activates the line pressure adjustment valve to increase pressure and prevent leakage. At low temperatures, normal pressure is maintained to avoid creep. This parameter adaptation resolves the contradiction between sealing performance and creep prevention.
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 design reduces the size and weight of the control device while maintaining functionality, preventing leakage at high temperatures and creep at low temperatures, and ensuring reliable operation by integrating multiple functions into a single valve.
Implementation Method 1
a fluid pressure control device (for example, a hydraulic pressure control device 100 of an embodiment; hereinafter the same) that includes a plurality of control valves (for example, solenoid valves 122A to 122F of an embodiment; hereinafter the same)
Data Source
AI summary
One solenoid valve included in a hydraulic pressure control device has at least two functions among the following (1) to (6) functions, (1) switching a state of a two-way clutch, (2) switching a state of a parking lock mechanism, (3) switching the supply of hydraulic pressure to a first brake that is put into an engaged state when a gear stage selected when driving of a vehicle starts is set, (4) controlling a line pressure adjustment valve so that a decrease in a line pressure is prevented when the temperature of a hydraulic fluid is a first predetermined temperature or higher, (5) preventing the occurrence of a creep phenomenon in a neutral range when the temperature of the hydraulic fluid is a second predetermined temperature or lower, and (6) boosting a line pressure by performing switching to another linear solenoid valve when the line pressure adjustment valve has failed.