Singh, S. and Ramaswamy, S., "Design of Clutch Pedal with Leaf Spring and Cam Mechanism to Reduce Clutch Pedal Effort," SAE Technical Paper 2015-01-1120, 2015, doi:10.4271/2015-01-1120.
1The modern engine is capable of producing high torque and horsepower. Now the customer wants state of the art comfort and ergonomics.Thus the manufacturers are focusing on reducing the clutch pedal effort and providing a pleasurable driving experience. In heavy traffic conditions where the clutch is used frequently, the pedal effort required to disengage the clutch should be in comfortable range. Often drivers who drive HCV complain about knee pain which is caused due to high pedal effort, this occurs when ergonomics of ABC (accelerator, brake and clutch) pedals is not designed properly. Thus there is a need to reduce the driving fatigue by optimizing the clutch system.Latest technologies like turbo charging and pressure injection have increased the engine power and torque but have also led to increase the clamp load of clutch. Thus the release load required to disengage the clutch has also increased. There are mechanisms integrated within the clutch pedal to reduce the load like Over-centre spring, Double torsion spring, Servo assist but each has its own limitations.This paper focuses on reducing the clutch pedal effort (load) without changing the clutch release load or hydraulic and mechanical ratios. This will be achieved by incorporating a leaf spring and a cam and roller mechanism in the clutch pedal itself. The mechanism provides the assistance to the driver during disengagement of clutch and also ensure good pedal return-ability while engagement. A prototype model was developed for a SUV after conducting a kinematic study and motion simulation. The results confirm the hypothesis showing that the pedal effort is reduced and comfort improved.