Operation of automatic transmission with manual gear shift (tiptronic)
Manual transmission, also known as tiptronic, combines the advantages of automatic and manual transmissions. It allows drivers to shift gears manually while maintaining the convenience of automatic gear shifting.
Main components:
* Torque Converter: Converts engine torque and ensures smooth gear shifting.
* Planetary gearbox: Uses gears and brake bands to select gear ratios.
* Hydraulic control unit: Controls gear changes and clutches based on input from sensors and gear selector.
* Gear Selector: Allows the driver to select the “D” position for automatic gear shifting or manual gear shifting using the lever or steering wheel paddles.
Working principle:
1. Automatic mode (position “D”):
– The automatic transmission independently selects and shifts gears depending on speed, engine speed and load.
2. Manual mode:
– The driver changes gears using the lever or steering wheel paddles.
– The automatic transmission directly connects the selected gear, transmitting torque from the engine to the transmission.
3. Motor protection:
– The electronic transmission control unit monitors engine speed and does not allow gear shifting to unsafe speeds.
4. Forced gear shift:
– If the engine speed is too high or low, the automatic transmission switches to a gear that matches the current driving conditions.
Advantages:
* Improved vehicle control
* Ability to select optimal gear ratios to improve dynamics or fuel economy
* Reduced clutch and gearbox wear
* Possibility of engine braking on steep descents
Flaws:
* Requires driver intervention, which may distract from the road
* More complex design compared to conventional automatic transmissions