Search Results

1 There are two design challenges of the flow path switching valve in a three-stage variable discharge oil pump. The first is to obtain the required discharge pressure characteristics and the other is to prevent hydraulic vibration. Therefore, we established technologies to determine the shape of the valve and the valve housing that resolve these two challenges. The technology to obtain the required discharge pressure characteristics solves equations that are statically true, such as the equations for the equilibrium of forces and hydraulic orifice. The hydraulic vibration control technology derives a differential equation that takes transient behavior, including oil elasticity and inertia, into account first. Then, the derived equations are converted to a transfer function that indicates the valve behavior according to the input of oil pressure changes. And then the stability criterion is applied to judge whether hydraulic vibration occurs or not.

Electric Active Stabilizer (EAS) system, that is capable of having a good balance between roll angle control and comfortable driving, has been developed. The EAS system can automatically control a roll angle by using the DC motor actuator installed in the center of a stabilizer bar. The actuator consists of a small brushless DC motor and a compact gear set. In order to improve vehicle drivability and to secure robustness against ambient temperature and power supply voltage fluctuation, we found that the motor rotation control was critical. In order to improve the motor rotation control, an actuator structure was optimized and H∞ control algorithm was introduced to have an excellent response and stability. As a result, the EAS system with high efficiency and reliable has been achieved. In this paper, the results are explained with a comparison between simulation results and experimental results.