Development of Accelerator–by–wire System for Variable Valve Lift and Timing Mechanism with Three Dimensional Cam

Although various types of engines with a variable valve lift mechanism have been developed and introduced, we have developed a Three Dimensional Cam for Variable Valve Lift and Timing mechanism (3D Cam VVLT) as a technology to simultaneously improve fuel consumption and power.

In 3D Cam VVLT, the position of 3D Cam slide decides valve lift and timing simultaneously. The 3D Cam VVLT is composed of a mechanical section including 3D Cam, an accelerator motor to drive the mechanical section, and an accelerator controller to control the cam position. The target slide position of the cam is calculated from engine speed and accelerator grip opening ratio. And the position of the cam is sifted by the accelerator motor.

The cam position control requires quick response time, stability, and smoothness.