Hydraulic Control System Neutral Locked Turbine Mode
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Solution Overview
Problem
Conventional hydraulic control systems for automatic transmissions fail to provide reliable multiple forward and reverse driving states during default conditions, where electronic control is lost, and struggle to rapidly heat vehicles in extreme cold without degrading performance.
Innovation Solution
A hydraulic control system incorporating a manual valve, default enable valve, default select valve, and clutch regulation valves, which allows for the engagement of clutches to provide neutral locked turbine mode, enabling two forward and one reverse gear ratios, and includes a pressure regulation subsystem to manage pressurized hydraulic fluid for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the transmission shifts to neutral during default conditions, then the system ensures safety by disengaging all gears, but the loss of driving capability and vehicle mobility occurs
Solution Approach 1:
The hydraulic control system is designed with pre-configured default paths that automatically engage specific gears (first forward gear or reverse gear) when electronic control is lost. This preliminary configuration ensures that upon electronic system failure, the transmission immediately defaults to a functional driving state rather than neutral, maintaining vehicle mobility while ensuring safety through predictable behavior.
2Temperature
If multiple clutches are engaged to lock the input shaft for rapid heating, then the heating capability is improved, but the loss of driving functionality occurs
Solution Approach 1:
The system dynamically configures clutch engagement based on the position of the manual valve. When the manual valve is in the 'P' or 'N' position, multiple clutches are engaged to lock the input shaft for rapid heating. When in 'D' or 'R' positions, the system maintains driving functionality by engaging only the necessary clutches for the selected gear, thus adapting the clutch configuration to the current operational context.
Solution Approach 2:
The manual valve acts as an intermediary that mediates between the heating function and driving function. Its position determines which clutch configuration is activated, allowing the operator to select between rapid heating (by positioning in 'P' or 'N') and normal driving operations (by positioning in 'D' or 'R').
3Adaptability or versatility
If the hydraulic control system is designed to provide multiple default gear states, then the adaptability during default conditions is improved, but the system complexity increases
Solution Approach 1:
The hydraulic control system is segmented into distinct functional modules: a manual valve for high-level mode selection, a default enable valve for enabling default operation, a default select valve for choosing between forward and reverse default gears, and individual clutch regulation valves for each clutch. This segmentation allows each component to have a specific, simplified function while the integrated system provides complex default gear state capabilities.
4Speed
If the manual valve is in direct fluid communication with clutch regulation valves, then the response time for clutch engagement is reduced, but the hydraulic pressure requirements increase
Solution Approach 1:
The manual valve is pre-configured in direct fluid communication with all clutch regulation valves, establishing ready-to-actuate hydraulic pathways before clutch engagement is needed. This preliminary configuration eliminates delay in hydraulic response when clutch engagement is commanded, as the fluid communication paths are already established and require only pressure activation.
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
Enables reliable operation of automatic transmissions with multiple gear states during default conditions and rapid heating of vehicles in extreme cold, enhancing performance and functionality without electronic control.
Implementation Method 1
a main pump that provides a pressurized fluid, such as oil, to a plurality of valves and solenoids within a valve body
Implementation Method 2
The valves and solenoids are operable to direct the pressurized hydraulic fluid through a hydraulic fluid circuit to various subsystems
Implementation Method 3
These torque transmitting devices may be, for example, friction clutches and brakes arranged with gear sets or in a torque converter
Implementation Method 4
a main pump that provides a pressurized fluid... to torque converter clutch control subsystems
Data Source
AI summary
A hydraulic control system for a transmission includes a reverse, a low gear ratio, and a high gear ratio during default conditions where the transmission loses electronic control. The hydraulic control system also provides neutral locked turbine capability that engages clutches to lock the transmission input shaft in order to generate heat. The hydraulic control system includes a manual valve, a default enable valve, a default select valve, and a plurality of clutch regulation valves. The neutral locked turbine capability may be engaged when the manual valve is in either a park or neutral position.