Double clutch

Between gas designated for vehicles with manual transmission a process to engage a lower gear and " double clutching " a process to engage a higher gear.

General

Downshifting with intermediate gas and the upshift with double domes is considered inevitable between non- synchronized gears in transmissions. The reason for this is that such transmissions are not capable, unlike the synchronized gears to adjust to the higher speed of the lower gear of itself to the lower speed of the overlying gear. The driver must adapt by an intermediate blast of the faster rotating lower gear, the speed of transmission. Conversely, he has to adjust by double clutching the speed of the gear to the more slowly rotating higher gear.

Method

The process of downshifting is done in five steps:

When the shift lever is in neutral position and the clutch is closed, a part of the transmission is coupled to the engine speed, while the other portion is coupled via the differential to the speed of the wheels. By blipping the speed of the motor-side transmission branch is increased and at a same speed as possible ( synchronous speed ) taken as the wheel-side transmission branch, so that may also be connected without synchronizing rings or with faulty synchronization.

The sequence of the upshift is similar:

Sometimes double clutching can also be omitted, because the transmission oil because of its viscosity, the auxiliary shaft also slows down a bit.

Between gas in modern transmissions

The gears in the gearboxes of today's cars are by synchronizing rings fully synchronized ( synchronous transmission ) to afford the intermediate gas has massively declined in importance. During the intermediate gas was essential even in cars without synchromesh, it is almost no longer used in normal traffic today and is no longer part of driver training. Usually it is applied only during sporty driving, to prevent the one hand, that the car is restless by load -change reactions, on the other hand, in order to optimize the switching process ( speed maintained during downshifting on the mountain or enabling better acceleration after the shift ), and the clutch (which then grinds only briefly) and to preserve the synchronization mechanism. Even in normal traffic between the gas, the synchronization mechanism and the clutch saves considerably.

With sequential gearboxes is usually given between gas automatically in Sport mode. Thus, the retarding torque of the motor is overcome so that the car accelerates faster again and the PTO is spared (load change is not necessary ). For automatic transmissions, however, intermediate gas is unnecessary because of the torque converter.

Double clutching

The double clutching is not necessary if you discreetly withdraws the gas. When load changes in the gear, the gear without domes can be pulled out. Then continue as described above. By accelerating the drive plate is brought to the correct speed, disengaged, inserted the smaller gear and re-engaged.

Special forms

• Heel and toe technology in motorsport

• Internal combustion engine
• Vehicle transmission