Economic ISG System for Automatic Transmission Vehicles
Solution Overview
Problem
Implementing an Idle Stop & Go (ISG) system in low-cost vehicles equipped with automatic transmission is challenging due to the need for additional components like sub-oil pumps and hill-start assist control devices, which increase costs and deteriorate commercial quality.
Innovation Solution
An economic ISG system is developed using a durable battery, battery sensor, reinforcing starter, brake boosting pressure sensor, and a controller that manages engine start/stop based on shift lever and brake states, eliminating the need for a sub-oil pump and hill-start assist control device, and utilizing a DC-DC converter to prevent voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional components (sub-oil pump, hill-start assist control device) are mounted to achieve ISG function in automatic transmission vehicles, then ISG functionality is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and eliminates the sub-oil pump and hill-start assist control device from the ISG system configuration. By using the existing automatic transmission hydraulic system and brake boosting pressure sensor, the system achieves ISG functionality without these additional components, directly reducing device complexity while maintaining adaptability.
Solution Approach 2:
The existing brake boosting pressure sensor is made multi-functional by using it for both brake pressure monitoring and ISG control decisions. The automatic transmission hydraulic system is made universal by utilizing its existing pressure for both transmission operation and hill-start assist functions, eliminating the need for dedicated hill-start assist control devices.
2Adaptability or versatility
If additional components (sub-oil pump, hill-start assist control device) are mounted to achieve ISG function, then ISG functionality is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes the sub-oil pump and hill-start assist control device from the component list, directly reducing manufacturing cost. The system achieves ISG functionality using only the battery, starter, brake boosting pressure sensor, and existing transmission hydraulic system.
Solution Approach 2:
The existing brake boosting pressure sensor serves dual purposes: monitoring brake pressure for normal operation and providing data for ISG control decisions. This self-service approach eliminates the need for additional sensors and control devices, reducing manufacturing cost while maintaining ISG functionality.
3Use of energy by moving object
If engine is stopped in idle state to improve fuel efficiency, then energy consumption is reduced, but hydraulic pressure stability deteriorates
Solution Approach 1:
The system performs preliminary action by maintaining hydraulic pressure through the existing transmission hydraulic system before engine restart is needed. The brake boosting pressure sensor monitors pressure levels in advance, and the control unit prepares for engine restart conditions before actual restart is required, ensuring hydraulic stability during idle stop periods.
Solution Approach 2:
The automatic transmission hydraulic system maintains continuous useful action by utilizing residual hydraulic pressure and the brake boosting system to sustain necessary pressure levels during engine idle stop. This allows the transmission to remain functional without requiring continuous engine operation, improving fuel efficiency while maintaining hydraulic pressure stability.
4Speed
If engine restart frequency is increased to maintain readiness, then responsiveness is improved, but battery durability deteriorates
Solution Approach 1:
The system applies partial action by using the brake boosting pressure sensor to determine optimal restart conditions. Instead of restarting at every possible opportunity, the system selectively initiates restarts based on actual hydraulic pressure needs and driving conditions, reducing unnecessary restart cycles and extending battery durability while maintaining adequate responsiveness.
Solution Approach 2:
The brake boosting pressure sensor provides continuous feedback on hydraulic pressure levels, allowing the control unit to make intelligent restart decisions. The system monitors pressure trends and only triggers engine restart when actually needed, rather than using fixed-time or overly frequent restart schedules, thereby extending battery life while maintaining system responsiveness.
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 approach improves fuel efficiency and commercial quality by reducing vehicle parts and manufacturing costs while maintaining ISG functionality without the need for additional components, ensuring stable engine operation and hydraulic pressure management.
Implementation Method 1
a battery having charging and discharging durability
Implementation Method 2
utilizing a DC-DC converter to prevent voltage drops
Data Source
AI summary
An ISG system makes it possible improve fuel efficiency of a vehicle by achieving an ISG system at a low cost in a vehicle equipped with an automatic transmission and considerably improve commercial quality of a vehicle by relatively reducing the parts and cost for manufacturing the vehicle, without using a sub-oil pump and a hill-start assist control device.