Search Results

In-wheel motors (IWM) will be a key technology that contributes to the popularization of electric vehicles. Combining electric drive with IWM enables both good vehicle dynamics and a roomy interior. In addition, the responsiveness of IWM is also capable of raising dynamic control performance to an even higher level. IWM enable vertical body motion control as well as direct yaw control, electric skid control, and traction control. This means that IWM can replace most control actuators used in a vehicle chassis. The most important technology for IWM is to enable the motor to coexist with the brake and the suspension arms inside the wheel. The IWM drive unit described in this paper can be installed with a front double wishbone suspension, the most difficult configuration.

The bores of the cylinder block are usually machined prior to assembly with the cylinder head. In this case, bore distortion occurs when the cylinder block is assembled with the cylinder head due to the load applied by the head bolts and the surface pressure of the head gasket. This bore distortion influences sealing and operating characteristics of the pistons and piston rings, requiring an increase in bore thickness and addition of ribs to obtain higher cylinder block rigidity, which lead to an increase in weight. In order to improve engine performance, it is necessary to control bore distortion more effectively. With the aim of reducing bore distortion when assembled with the cylinder head, the bores are machined with a dummy cylinder head installed on the block to provide an equivalent head bolt load and gasket surface pressure. By using this bore circulatory machining technology, bore distortion after cylinder head assembly can be reliably suppressed.

Attaining optimum balance between longitudinal compliance and sideforce compliance steer in a torsion beam suspension system is a challenging task. We developed a suspension in which the longitudinal compliance is almost doubled and the side force compliance steer amount is improved by using the link effect of toe control links. This suspension system has been developed to realize excellent controllability, stability, riding comfort, and road noise performance.