Controlled Clutch Forces CCF

Current design of the CCF for a self-calibrating clutch

General

Particularly with high supercharged diesel engines a continuous increasing of the torque can be observed. This leads to increasing disengaging forces of the mechanical operated clutches. The solution is the CCF (Controlled Clutch Forces) clutch master cylinder, a pure mechanical system for the pedal force support.

The advantages & benefits of the CCF are:

• Reduction of the operating force
• Reduction of the pedal travel
• Free definalbe pedal characteristics
• Easy change to friction discs
• Low production costs
• Simple construction.

Important force reduction at the pedal

Technical description

The CCF is composed of the cylinder housing with enclosed piston, the connecting rod actuation with connection to the clutch pedal, the booster and the force transducer with three roller-bearings and cone.

The work stored in the servo spring is released by declutching via the deflector rolling off a cone and generates the pedal force support. Various pedal force characteristics can be adjusted by calbibrating the cone profile and the spring force.

During clutch engagement the spring is clamped for the next clutch actuation.

CCF with hydraulic wear adjustment

The system can optionally be equipped with a hydraulic wear adjustment. The figure "Force progression at worn friction disk" shows the force characteristics of the friction disc of the clutch pedal in the state of wear.

Force progression at worn friction disk

The characteristics show a maximum force increased by approx. 100 N of a worn friction disc.

Design for a CCF with wear adjustment

While wearing off the friction disc the operating point of the clutch membrane spring slips. This increases the release force of the clutch actuation. During lifetime the wearout of the clutch friction disk leads to an rising actuation force. The CCF compensates this by a progressive increase of the servo force. This wear adjustment is not noticeable by the driver and leads to a constant actuation force over lifetime of the clutch.