A direct push clutch (DPC) was developed to enhance the controllability of clutch torque in a Formula One clutch system. A direct push mechanism in which clamp force was generated by a plate with the function as lever and a hydraulic actuator was employed in place of the previous mechanism, in which the clamp force was generated by a diaphragm spring. The transition from stroke control to direct control of the clamp force did away with elements that formerly produced changes in system characteristics, such as variations in the diaphragm spring characteristic and spring hysteresis, and thermal expansion throughout the system. In combination with other enhanced control technologies, this enabled the development targets for the system to be realized. This helped to enable half-clutch starts (slip starts) to be employed from 2006, even after regulations prohibited the use of feedback control. As a result, a maximum reduction in time from 0-100 km/h of 0.46 sec (corresponding to a distance of approximately 11 m) was obtained, giving the vehicle a competitive advantage. The developed system was used in races from the first race of the 2006 season.
Article of Honda R&D Technical Review F1 Special (The third Era Activities) (136 - 141)