Search Results

A new engine starter is developed for the purposes of downsizing and improving response time. A feed screw is used in the proposed starter, and its behavior is as follows. The motor shaft connected to the feed screw rotates, and the pinion gear with an internal screw then moves along its axis and stops at the end of the screw. The ring gear connected to the engine is located at the same axial position at which the pinion gear stops. Therefore, the pinion gear is engaged with the ring gear, and the engine is turned over. While a conventional starter requires a solenoid actuator to move the pinion gear, this device does not because the rotational movement of the screw is converted to the axial movement of the pinion gear. However, there is a problem whereby the rotational speed of the motor shaft decreases when the gear pair is engaged. This problem is resolved by adding a coil spring between the pinion gear and the end of the screw.

1 In general, the engine brake performance of a vehicle with an automatic transmission (AT) is inferior to that of a vehicle with a manual transmission (MT), without manually downshifting the transmission. Especially, in commercial vehicles having great variations in load capacity, improvements in engine brake performances are significant issues for vehicles with an AT in terms of both safety and performance. For such circumstances, Aisin Seiki has succeeded in the development of a 6-speed AT for commercial vehicles with an engine control system that enables the vehicle to decelerate according to desire of drivers in various driving conditions. An outline of the development of this control system is presented below.

The performances of some vehicle control systems are influenced by changes in the weight of the vehicle. In these systems, it is important to be able to estimate the weight without the need for special sensors. When we use physical models to do this, we have to provide estimates for two or more unknown parameters. In addition, since such a method is influenced by disturbances in the measured signals, it is difficult to maintain an acceptable level of accuracy. So, after analyzing the physical phenomena, we developed a new method that eliminates the influence of the disturbances from the measured signals and constructed an estimation system that has a minimum number of unknown parameters that was capable of providing a more accurate estimate of a vehicle weight. This method was applied to the braking force control of an automatic transmission and its efficacy was verified.