Liu Zhongchang, a professor and doctoral supervisor of the internal combustion engine department of the Jilin University College of automotive engineering, also believes that the VVT technology is mainly to change the gas supply according to the needs of engine. "At present, VVT technology has been popularized in the field of cars, and the use in commercial vehicles is relatively small. If the energy saving and emission reduction demand of commercial vehicles in the next stage is relatively strong, it may be used." Liu Zhongchang said that the use of VVT technology can be said to be relatively small for commercial vehicle companies worldwide. Today, Dongfeng new V29 model is using this technology, it can effectively improve the market competitiveness.
"To improve the fuel economy is the biggest feature of using VVT technology." Beijing Institute of Technology School of mechanical and vehicle, vehicle dynamics and emission test of national professional laboratory director Ge Yunshan believes that the general diesel engine speed is at 2000 rpm, the general gasoline engine speed can reach 5000~6000 rpm around, so the use of VVT technology can better play a regulating role and improve fuel consumption.
V29 conforms to market demand
Improving fuel economy means solving user's biggest trouble at the beginning. In early 2012, the NDRC increased oil price again. With the increasing pressure of oil prices, most users began to show signs of delisting. How to tap the real needs of the commercial vehicle users is not only the direction of the enterprise, but also the responsibility of the enterprise. Today, Dongfeng launches the V29 model with the face of high-end micro guest, which is to meet the demand of the micro guest market to save fuel economy .
"The minibus and the car's displacement are basically the same, and the power range is almost the same. Therefore, the introduction of VVT technology to the field of Micro customers is basically the same." Zhang Shuyong believes that the engine used in the mini car could not run for a long time in a certain working condition, so the biggest advantage of the use of VVT technology in different conditions, is to improve fuel economy. By improving the fuel economy, it can also improve the vehicle emission.
Zhang Shuyong also said that by adjusting the valve, the intake efficiency can always maintain a high inflation efficiency. This way, it can ensure that users can maintain the best aeration efficiency in different working conditions to meet the needs of engine combustion. "Like a high-pressure common rail valve, if the valve is good, it can ensure that the oil can be more in a certain pulse width. In the same way, if the external pressure and flow rate are well adjusted, the biggest problem is the valve timing, which directly determines the inflating efficiency. In this case, if it is variable, it can maintain a higher charge coefficient under different operating conditions."
"In any way, this technology will be popularized in the commercial car industry sooner or later." Zhang Shuyong believes that in the future commercial vehicle field, whether VVT or CVVT (continuous variable valve timing technology) or other engine technology will be widely applied.
Liu Zhongchang also acknowledged this. He said: "This is an inevitable trend. With the increasingly stringent energy saving and emission reduction requirements and market demand, it is not only for minibus, even heavy trucks will also be able to use this technology in the future."
The future of VVT is broad