Ensure a smooth start of the car
This is the primary function of the
clutch. Before the car starts, it is natural to start the engine first. When the car starts, the car gradually accelerates from a completely stationary state. If the drive train (which links the entire car) is rigidly connected to the engine, as soon as the transmission is put into gear, the car will suddenly rush forward, but it will not start. This is because the car has a great inertia when it goes from a standstill to a forward stroke, which causes a great drag torque on the engine. Under the action of this inertial resistance moment, the engine speed drops sharply below the lowest stable speed (generally 300-500RPM) in a moment, and the engine stops and cannot work, of course the car cannot start.
Therefore, we need the help of the
clutch. After the engine is started and before the car starts, the driver first steps on the
clutch pedal to disengage the clutch to disengage the engine from the driveline, then put the transmission in gear, and then gradually release the clutch pedal to gradually engage the clutch. During the engagement process, the resistance torque received by the engine gradually increases, so the accelerator pedal should be stepped down gradually at the same time, that is, the fuel supply to the engine should be gradually increased, so that the engine speed is always maintained at the lowest stable speed without stalling. At the same time, due to the gradual increase in the tightness of the clutch engagement, the torque transmitted by the engine to the driving wheels through the driveline gradually increases. When the traction force is sufficient to overcome the starting resistance, the car starts to move from a standstill and gradually accelerates.
Achieve smooth shifting
In the driving process of a car, in order to adapt to changing driving conditions, the transmission system often needs to change different gears to work. To realize the gear shift of the gear transmission, it is generally to toggle a gear or other gearshift mechanism to push a gear pair of the original gear out of the transmission, and then make the gear pair of the other gear enter the work. Before shifting gears, the
clutch pedal must be depressed to interrupt the power transmission to facilitate the disengagement of the meshing pair of the original gear. At the same time, the speed of the meshing part of the new gear meshing pair gradually tends to be synchronized, so that the impact when entering the mesh can be greatly increased. Reduced to achieve smooth shifting. 3. Prevent the drive train from overloading.
When the car is in emergency braking, if there is no
clutch, the engine will be rigidly connected to the drive train and the speed will be drastically reduced. Therefore, all the moving parts will generate a large moment of inertia (its value may be much higher than that issued by the engine during normal operation). The maximum torque), which causes a load exceeding its carrying capacity to the drive train, and damages the mechanical parts. With the clutch, the possible relative movement between the driving part and the driven part of the clutch can be used to eliminate this danger. Therefore, we need a
clutch to limit the maximum torque of the drive train to ensure safety.
