However, Bian Xiao is more concerned about innovative technologies that can be enjoyed in places not far from us, including CVT4EV gearbox developed by Bosch for electric vehicles, as well as steer-by-wire and clutch control.
Synergistic drug for electric vehicles: CVT4EV
At present, most electric vehicles on the market are not equipped with variable speed gearboxes, because the speed of the motor can reach tens of thousands of revolutions, and the torque can reach the peak at the beginning, which is enough to push the car to a certain speed.
However, the problem is that when the motor speed reaches a certain range, the winding inductance, back electromotive force and external resistance will make the motor torque decrease rapidly, which is also the reason why the electric vehicle will become weak when driving at high speed.
More importantly, high motor speed = high power consumption, so the car factory will equip the car with a battery pack with larger capacity and higher weight, so some high-end electric vehicles such as Porsche pay more attention to performance. Tekan will be equipped with a two-speed transmission.
However, Bosch exhibited the CVT4EV gearbox specially developed for electric vehicles at this event, which is very topical!
Because CVT has the ability of stepless speed change, it can be flexibly adjusted between wide speed ratios. It is possible to amplify the torque required to start the vehicle, or let the motor drive the vehicle at a low speed and high speed. For example, CVT4EV can increase the maximum speed of vehicles by 65,438+00% and improve power consumption/output efficiency by 4%.
Actually through a "modified" CVT4EV gearbox? Chery Arrizo 5e experience, you can clearly feel that this car has CVT blessing, and the sense of starting acceleration becomes closer to the taste of performance super-running, but at the speed of 100km/h, the sound of motor running is obviously not so high. More importantly, when you step on the switch when you are out of the corner, you will feel full of strength, which is really enjoyable.
Bian Xiao deliberately squatted on the ground and looked at the dry Kun of this gearbox. In fact, the volume is not much bigger than that of the general single-stage reducer of electric vehicles, and the installation problem is not big! And if we calculate the cost, take a smaller motor and battery with this gearbox, which has better power and more energy saving, then it may be worth considering and applying by the car factory.
Of course, some people may doubt whether the CVT gearbox can withstand the large torque of the motor, but according to Cai Zhijian, technical director of Bosch (Shanghai), the steel belt of CVT4EV can withstand the torque of 600Nm, which is believed to be enough for most electric vehicles.
Driving is more interesting and worry-free.
There is also a clutch management system at the event site. To put it bluntly, this thing is a set of automatic mechanism for manual clutch. As early as the 1990s, Renault's Twingo has been applied. So what's so special about Bosch's system?
It is unique in that it is highly integrated with the vehicle-mounted power system, which can properly control the engine speed according to the driver's different gear shifting actions, and can also remind the driver of gear shifting actions according to certain energy consumption and economy.
Moreover, in the past, as long as Twingo put the driver's hand on the shift lever, the shift pressure sensor judged and controlled the semi-clutch, which easily caused the clutch plate to burn out. Bosch's clutch management system can judge whether the driver is used to putting his hand on the shift lever or really has the intention of shifting gears through logical programs.
The experience car is Wuling Hong Guang S, which is known as the "mountain car". Without the clutch pedal, the feeling of driving this car becomes more carefree and relaxed, and there is no danger of going backwards when starting uphill.
In addition, Bosch's clutch control response is quick and flexible. In addition to driving experience, it is perfect if it is used in a stop-and-go environment in urban areas. Technology doesn't have to overthrow the past. It is also an achievement to make the original technology more perfect!
In addition, there is steering by wire about steering technology. Bian Xiao specially asked the on-site technicians. He said that there is no hard connection or backup connection mechanism between the steering wheel and the steering machine of this system, but there is no problem in safety, because this steer-by-wire system was developed for the needs of automatic driving and must pass many safety tests before it can be applied.
I saw in the modified Audi A3 experience car with steer-by-wire system that many computer equipments are still in the co-pilot position, which is convenient for engineers to flexibly adjust the working characteristics of the system.
At present, this steering-by-wire system can provide a variety of steering mode experiences, from the most comfortable steering wheel to the left dead center of 1.5 laps, and then to the most sports steering wheel 180 degrees, with huge differences. Obviously, the latter is more flexible and easy to use when passing through some tricky corners.
Moreover, the accuracy of this system is very high, and the texture of pavement feedback is also well handled. I hope my car can also be modified into such a steering system!
Future travel &; Development potential of commercial vehicles
At the activity site of the experience day, a summit forum of the focus observation room was also held. Xu Daquan, executive vice president of Bosch China, talked with many experts and scholars about the possibility of autonomous driving, enjoying travel and even air-ground cooperation, which put forward many possibilities for people's future travel technology.
In addition, some people may think that the epidemic has had a great impact on the passenger car market, but there is absolutely no objection that the commercial vehicle market has grown rapidly during this period. After all, all kinds of medical and living materials should be transported by commercial vehicles. Bosch's fifth-generation millimeter-wave radar, third-generation camera and Servotwin electro-hydraulic power steering system for commercial vehicles also appeared at the event site. In addition to realizing the ADAS function that can be realized at present, it also foresees the future of automatic driving of commercial vehicles.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.