See such a question: the clutch pedal is the heaviest of the three pedals of the manual car, then why don't the manufacturers design the clutch pedal lighter? In fact, this problem is very simple, we can analyze it from the following points:
Why is the clutch pedal so heavy
The clutch pedal is definitely the heaviest for a car with a hand shift, and that has to do with how it works. You know what you're driving when you step on the clutch? It's a huge spring.
Because the clutch is transmitted by friction force, the engine torque is so large, want to ensure that the clutch does not slip must be the Clutch Plate clamping, so there is a huge diaphragm spring on the pressure plate, can produce a great clamping force to ensure that the clutch can normally transfer large torque without slipping. But when you step on the clutch you have to overcome the spring force to disengage the clutch. So the clutch pedal is the heaviest.
And the gas pedal is very light, because they drive the throttle, early pull type throttle above the biggest resistance is the return spring, but the elastic force is extremely limited, a toe can step, not to mention the whole foot. Many cars now have electronic throttles, which make the pedal lighter.
Although the brake pedal is very light to step on, it is because of the vacuum assist, if not assisted, the brake pedal is definitely much heavier than the clutch pedal.
Why not make the clutch pedal lighter
There are three main ways to lighten the clutch pedal:
The first is to reduce the spring force of the pressure disc, but obviously this is not practical. Because the fall of the elastic force means that the clutch is not strong enough, the clutch is easy to slip.
The second is to increase the lever proportion of the clutch pedal, because the clutch pedal itself is a lever structure, increasing the lever proportion can make the pedal become lighter. But unfortunately this is not practical, because the increase of lever ratio after the clutch pedal travel will also increase, affecting the driving. After all, you don't want to have to raise your leg when you step on the clutch.
The third is to increase the power of the clutch, this is a can be achieved, for example, many heavy truck clutch with power. But the problem is that the truck engine is often thousands of meters of torque, in order to ensure that the clutch does not slip that the spring force is too large, do not have to step on the power completely, have to use the power. And the strength of the clutch pedal of the home car is acceptable to most people, so there is no influence without help.
More importantly, increasing power will increase the cost, not only the cost of power equipment, the structure of the clutch and transmission should be changed. And the clutch pedal different positions of its resistance characteristics are different, if simply increase a constant power, then the clutch is lighter, but the pedal feedback will become very fuzzy. And if you want to maintain the original characteristics of the clutch, the cost will continue to increase, so manufacturers might as well go straight to the automatic transmission.
Cause of abnormal clutch weight
Some faults or small problems will also cause the clutch to become heavy, the most common in daily use of cars is the following situations:
1. The clutch cable is damaged
Many of today's manual gears are hydraulic clutches that use brake fluid to transfer power. But there are still a part of the car clutch is used to transfer power with cable, some cars after the use of a long time after the cable and line wall friction gap leads to the cable is sandwiched in the gap to increase the movement resistance, at this time the clutch will become heavy.
2, the clutch plate wear
Clutch plate wear can also cause the clutch pedal to become heavier, which is a problem many people don't realize. Because the disc's diaphragm spring deformates more after the clutch plate is worn, more effort is needed to push the diaphragm spring apart when stepping on the clutch.
3, pressure disc diaphragm spring wear
The disc diaphragm spring can also cause the clutch to become heavier when worn. Because the pressure disc diaphragm spring has many strips, under normal circumstances when stepping on the clutch, the separation bearing is to push all the diaphragms together to separate, so that the whole spring body is evenly stressed and easy to separate.
4, separation bearing seat resistance is large
When stepping on the clutch, the separation bearing will move forward and backward. Some people like to butter the bearing seat when replacing the separation bearing, so that the separation bearing movement can get better lubrication. In fact, this approach is to gild the lily. Because the speed of the separation bearing is very slow, and the friction between the bearing and the bearing seat is very small, even if there is no lubrication, it is difficult to wear. But after the spread of butter will increase the movement resistance of the separation bearing, so that the clutch becomes heavier. In particular, the clutch plate will wear off a lot of dust in the process of use, stick on the butter will make the butter become thick and hard, which can only further increase the resistance of the movement of the separation bearing.
So when replacing the separation bearing, there is no need to butter the bearing seat extra, otherwise the clutch pedal will be more and more heavy after a period of use.
