抄録
In recent years, the hydraulic system of the automatic transmission of a passenger car is becoming more simplified and light-weighted by virtue of the development of the technology of the electronic control and the actuator. Nevertheless, it shows improved shift quality. Following this trend, we design a clutch direct-drive circuit (CDDC) which have one proportional solenoid valve for one clutch, which controls each clutch during shifting. For the analysis of this proportional solenoid valve, we divide this valve into two subsystem: an electrical subsystem and a hydraulic subsystem. Each subsystem is modeled in detail and we verify the reliability of this detailed model through experiments. It turns out that this valve is able to control a clutch pressure precisely enough to obtain good shift quality. For a shift control, we design a control algorithm and are confirmed that the performance of the transient torque reduction is good enough through the feedback shift control experiment at the automatic transmission dynamo which has a hydraulic system using a CDDC.
