Transmission Lubrication Control via Dynamic Oil Flow Regulation
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Solution Overview
Problem
Existing lubrication control devices for transmissions, such as those described in Japanese Patent Application Publication No. 2002-266993, face inefficiencies in reducing transmission loss due to excessive oil flow rates and delayed warm-up, as they do not effectively manage oil flow to optimize temperature increase and lubrication efficiency.
Innovation Solution
A lubrication control device comprising an oil pump, a heat exchanger, an oil quantity control valve, and an electronic control unit that adjusts the opening degree of the oil quantity control valve based on oil temperature, allowing only the required amount of warmed oil to reach the lubricated portions, thereby reducing stirring and dragging losses by controlling the flow rate and bypassing surplus oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the hydraulic oil flows through the oil cooler at a high flow rate, then the cooling capacity is improved, but the temperature rise of the hydraulic oil becomes slight and the warm-up of the transmission is delayed
Solution Approach 1:
The patent applies dynamic control by using an electronic control unit to adjust the opening degree of the oil quantity control valve based on real-time oil temperature feedback. The system transitions from static ON/OFF control to dynamic proportional control, allowing the oil flow rate to be continuously adjusted according to temperature conditions, thereby optimizing both warm-up speed and temperature rise efficiency.
Solution Approach 2:
The patent changes the flow rate parameter of hydraulic oil dynamically based on temperature conditions. By adjusting the opening degree of the oil quantity control valve, the system varies the oil flow rate through the heat exchanger, enabling optimal temperature rise during warm-up while preventing excessive flow that would reduce temperature increment.
2Reliability
If a large amount of hydraulic oil is supplied to the lubrication circuit, then the lubrication is improved, but the transmission loss increases due to excessive stirring and dragging
Solution Approach 1:
The patent applies partial action by supplying only the required amount of warmed hydraulic oil to the lubrication circuit rather than the full flow. The oil quantity control valve restricts the flow to match the actual lubrication needs, preventing excessive oil from causing unnecessary stirring and dragging losses while still providing adequate lubrication.
Solution Approach 2:
The patent applies local quality by providing differently conditioned oil to different circuits. The lubrication circuit receives a controlled amount of warmed oil with optimal temperature and flow characteristics, while the remaining oil bypasses the lubrication portion. This localized optimization ensures proper lubrication without the penalty of excessive oil flow throughout the entire system.
3Temperature
If the hydraulic oil is cooled excessively in the oil cooler, then the temperature control is improved, but the transmission warm-up is delayed and fuel efficiency deteriorates
Solution Approach 1:
The patent implements feedback control by using a temperature sensor to detect the actual hydraulic oil temperature and feeding this information back to the electronic control unit. The ECU adjusts the opening degree of the oil quantity control valve based on this feedback, creating a closed-loop control system that prevents excessive cooling while ensuring adequate temperature control, thereby optimizing fuel efficiency.
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 configuration reduces transmission loss by optimizing the flow rate of oil to the heat exchanger, increasing the temperature increment of the oil, and minimizing the amount of oil supplied to the lubricated portions, leading to improved fuel efficiency and reduced losses during warm-up.
Implementation Method 1
The heat exchanger is configured to perform heat exchange between the oil and a liquid-phase medium circulating in an engine
Implementation Method 2
The oil quantity control valve is configured to control a supply oil quantity as a flow rate of the oil flowing from the inflow port to the supply port
Data Source
AI summary
A lubrication control device for a transmission includes an oil pump, a heat exchanger, an oil quantity control valve, a first bypass oil passage, and an electronic control unit. The heat exchanger is connected between the oil pump and a lubricated portion of the transmission. The oil quantity control valve includes an inflow port, a supply port, and a discharge port. The supply port is connected to the heat exchanger. The oil quantity control valve is configured to control a supply oil quantity as a flow rate of the oil flowing from the inflow port to the supply port and discharge a residue of the oil from the discharge port. The first bypass oil passage is connected to the discharge port. The electronic control unit is configured to adjust the oil quantity control valve such that the supply oil quantity increases as a temperature of the oil increases.