Dual-Pump Hydraulic Control for Transmission Fuel Efficiency
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Solution Overview
Problem
Existing hydraulic control devices for vehicle transmissions face challenges in determining whether the operation of a second pump effectively improves fuel efficiency, as the methods for calculating the reduced work rate of the first pump and power consumption of the second pump are not accurately assessed, leading to uncertainties in energy efficiency improvements.
Innovation Solution
A hydraulic control device with a control part that determines the operating/stopping of the second pump based on the difference between the reduced work rate of the first pump and the power consumption of the second pump, using estimated and actual values of pressure and rotation speed to calculate the power consumption, allowing for appropriate determination of energy efficiency improvements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the second pump is operated to pressurize oil and supply it to the hydraulic operation part, then the work load of the first pump is reduced and fuel efficiency is improved, but the power consumption of the second pump increases
Solution Approach 1:
The control device changes the operating parameters (rotation speed, torque) of the second pump based on real-time measurements to optimize the balance between reducing first pump workload and minimizing second pump power consumption. By dynamically adjusting these parameters, the system achieves fuel efficiency improvement while controlling energy usage of the second pump.
Solution Approach 2:
The system implements feedback control by measuring actual rotation speed and torque of the second pump, and using this information to determine whether to operate or stop the second pump. This feedback mechanism ensures that the decision to operate the second pump is based on actual energy efficiency improvements rather than estimated values alone.
2Device complexity
If the operation of the second pump is determined based on estimated values of pressure and power consumption, then the control is simplified, but the accuracy of energy efficiency assessment is insufficient
Solution Approach 1:
The system replaces purely estimated/calculated energy efficiency assessment with actual measurement-based determination. By substituting estimated values with measured values from sensors, the system achieves more accurate energy efficiency assessment without excessive complexity increase, as the measurement infrastructure is already present in the hydraulic control device.
3Loss of energy
If the second pump is frequently switched between operation and stop states to optimize fuel efficiency, then energy reduction efficiency is improved, but frequent switching occurs which may reduce system reliability
Solution Approach 1:
The control device implements dynamic control of the second pump operation based on real-time measurement of actual rotation speed and torque. This dynamic approach allows the system to optimize energy reduction efficiency by switching the second pump only when measurements confirm actual energy efficiency improvement, rather than following fixed schedules or estimates, thereby reducing unnecessary switching and improving system reliability.
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 control device effectively determines when to operate or stop the second pump to enhance fuel efficiency by accurately assessing the energy efficiency improvements, preventing frequent switching and optimizing energy reduction efficiency.
Implementation Method 1
pressurizing with the second pump (30) the first oil supplied from the first pump (20) and supplying the pressurized first oil as a second oil to the hydraulic operation part (56)
Implementation Method 2
when the discharge amount (flow rate) of the second oil from the second pump exceeds the flow rate (discharge amount of the first oil from the first pump) of the first oil passing through the bypass valve, the hydraulic pressure (line pressure PH) in the downstream oil passage of the bypass valve becomes higher than the hydraulic pressure (output pressure P1) in the upstream oil passage
Data Source
AI summary
The disclosure provides a hydraulic control device. The operating/stopping of the second pump is determined based on a value of a difference between a reduced work rate of the first pump when the second pump is operated and a power consumption of the second pump. In a state where the second pump is stopped, the power consumption of the second pump is calculated based on an estimated value of a pressure of oil supplied to the hydraulic operation part and an estimated value of a pressure of oil supplied from the first pump to another hydraulic operation part or a lubrication target operating at a lower pressure than the hydraulic operation part. In a state where the second pump is operated, the power consumption of the second pump is calculated based on an actual rotation speed and an actual torque of the second pump.