I don't know if you have found that when the automatic transmission vehicle is switched in gear, the PRND gear is switched, the owner must step on the brakes, why should the automatic transmission vehicle be designed like this? Can't you shift gears without stepping on the brakes? "AutoMotive Overview" gives you a little white popularization of automatic vehicle gear switching related knowledge!
First of all, to popularize the automatic transmission gear switching, its gear switching mainly includes two kinds, one is the static P, R, N, D gear switching, the owner in the case of parking P, R, N, D gear operation; the other is slowly upgraded from 1 gear to the highest grade, through the change of transmission gear to optimize the engine speed control, improve the torque output of the engine, while optimizing the fuel efficiency of the engine. Here are the explanations for these two situations:
P, R, N, D gear switching
For the automatic transmission P, R, N, D gear switching, in fact, only P gear to switch to other gears need to step on the brakes, any other control process is not required to step on the brakes, including RN, NR, RD, DR, ND, DN and all other gear switching, if you do not believe, you can use your own vehicle to try it yourself!
Why do I have to step on the brakes when switching P gears?
P gear is a parking gear, the vehicle will only hang P gear when parking, when the owner starts the engine, if you want to switch from P gear to D or R gear, you can only step on the brake, stepping on the brake is equivalent to a preparation signal, proving that the owner has been prepared to drive, in this case, the owner will switch gears will be in a relatively safe state, but also effectively avoid the owner of the wrong operation when driving the vehicle.
When statically shifting gears in D or R gears, there is no need to step on the brakes
When the owner is moving forward in D gear, it is possible to switch to R or N gear without pressing on the brakes. When the owner switches to R gear, if the TCU detects that the speed of the vehicle is very high, the clutch of the R gear will not intervene in the work, at this time the vehicle will still drive forward, and the R gear is in an invalid state; when the vehicle switches to N gear, the transmission will be in neutral gear, which is also a common operation. When the owner is moving in R gear, he can still switch to N or D without stepping on the brakes, and the control principle is the same.
The reason why we think that the "R gear or D gear" gear switching needs to be stepped on the brakes, it is entirely because the owner is waiting for the red light (DN), reversing (DR, RD) and other special conditions when switching gears, in this case, the owner needs to control the speed through the brakes, not by stepping on the brakes to change gears.
The automatic transmission is up and down normally and does not require any operation
When the owner is driving a manual transmission vehicle, only need to control the clutch to switch gears, master the semi-linkage control of the clutch, we can skillfully and accurately switch gears, according to this principle, manual transmission vehicles in the gear switch, there is no need to step on the brakes, only need to control the clutch, and the clutch of the automatic transmission vehicle is automatically controlled by the TCU, the owner does not need any control at all to switch gears.
In fact, the automatic transmission vehicle is designed in this way, the owner in the driving vehicle, with the increase in speed, the automatic transmission can be slowly increased from 1 gear to top gear, the owner only needs to step on the accelerator to accelerate, do not need to step on the brakes or step on the clutch and other irrelevant operations, is not super simple?
In summary, when the automatic transmission vehicle switches gears, only the P gear needs to be stepped on when switching to other gears, and any other gear switching does not need to be stepped on the brakes.