Clutch System Description

Self-Adjusting Clutch (SAC)


Function

On ordinary clutches, the clutch pedal load increases as the clutch disc wears. The self-adjusting clutch is designed so that the clutch pedal load will not increase even when the clutch disc wears. This is done by automatically adjusting the fulcrum of the diaphragm spring in accordance with the wear of the clutch disc. The clutch pedal load stays consistent even when the clutch disc is worn.

Construction

The self-adjusting clutch consists of a pressure plate, a sensor spring, a diaphragm spring, an adjusting ring, three coil springs, a pressure plate cover, and a compensation spring. They are riveted together and must not be disassembled. If there is problem with any part of the pressure plate or clutch disc, they must be replaced as a set.

 

Operation


1.When the clutch disc wears slightly.
As the clutch begins to wear, the release load increases slightly. However, this does not affect the operation of the clutch because the release load does not exceed that of the sensor.

 

2.When the clutch disc wears considerably.
The sensor spring starts to deflect as the clutch disc is worn further and the release load exceeds that of the sensor.

 

The fulcrum then moves following the amount of sensor spring deflection. As this takes place, the fulcrum of diaphragm spring is adjusted, keeping the release load consistent.

 

Dual Mass Flywheel


Function

The dual mass flywheel is designed to reduce the noise and vibration produced by the engine, clutch, and transmission during acceleration and cruising.

Construction

The flywheel assembly is actually two flywheels in one, which raises the inertial mass on both the engine and transmission. The inner and outer flywheels are connected by high and low torsion springs. This combination effectively dampers changes in engine speed before they are transmitted to the transmission.
Since there are high and low torsion springs between the flywheels, none are used in the clutch disc, which lessens the inertial mass on the mainshaft. This reduction of the rotating inertial mass reduces the load on the synchro rings, allowing the transmission to shift smoothly. Also, the friction plate is designed to reduce the noise when the engine starts and stops.

 

 

Delay orifice mechanism


Function

The one-way orifice mechanism is designed to improve the operation performance of the clutch by delaying the slave cylinder releasing speed at the time of sudden release of the clutch pedal.

Construction

The delay orifice mechanism is built into the cylinder, and cannot be disassembled.

 

Operation

When pressing down on the clutch pedal, the fluid pressure sent from the master cylinder moves the one-way valve in the direction shown in the illustration. At this time, the fluid pressure is sent into the slave cylinder going through two passages, the orifice part and the filter part, and then it releases the joint of the pressure plate and the clutch disc.

 

When releasing the clutch pedal, the fluid pressure sent back from the slave cylinder moves the one-way valve in the direction shown in the illustration. At this time, the one-way valve blocks a passage of the filter part and delays the clutch releasing speed by returning the fluid to the master cylinder going through only a passage of the orifice part.