As for the gearbox, 1.4t is a 7-speed dual clutch (the gearbox doesn't know how to completely deal with this problem. . But the fuel consumption will be more economical), that is, 1.8t? 6-speed dual clutch (few problems), please see the reprint below for details.
The 3 rd.15 party in 20 13 pushed Volkswagen DSG powershift to the forefront, which can also be said to have written a conclusion for the fierce debate about DSG this year. Unlike this year's cover-up, the public official humbly apologized on the evening of the party and promised to provide a solution. So where does this magical question come from? This paper attempts to analyze and discuss with you in depth. Let's see clearly.
DSG powershift, once regarded as a fetish by Volkswagen Group and Volkswagen fans, is actually not complicated and mysterious. It first appeared in 1939~ 1940 more than 70 years ago, and it was precisely because of its unreliability that it ended in a flash in the pan. The so-called DSG (direct shift gearbox) transmission is actually a literal translation of English "direct shift gearbox". Its essence is manual shifting or it can be regarded as a more advanced AMT. The core is to replace manual shift and AMT simple and rude shift with smarter shift control program. Secondly, relying on better materials to make clutch plates requires superior wear resistance and can accept direct impact shifting (dry DSG) without lubricating oil. Therefore, DSG transmission has the advantages of small transmission power loss and fast shift time.
First of all, we need to recognize a concept. The problem transmissions announced at the 3. 15 party are all 7-speed dry DSG, but another 6-speed wet DSG of Volkswagen is rarely mentioned. This is because the structures of the two transmissions are different, and even their production companies are different. From Borgwarner (6 speed) and Luke (7 speed).
6-speed DSG powershift is used in familiar GTI, Magotan 2.0TSI and other models, and its code name is DQ250. The control module of the 6-speed DSG is provided by Borgwarner, which adopts wet clutch and can bear the maximum torque of 350NM. Mainly used for high-performance or main handling vehicles, such as Magotan and Golf GTI.
The latter model is a 7-speed DSG power shift car, which was in trouble this time. The 7-speed transmission code DQ200 was developed by LuK, a subsidiary of Schaeffler, Germany. Adopt dry clutch structure, which can bear the maximum torque of 250Nm. It is mainly used for small or economical vehicles with small displacement engines such as 1.2TSI and 1.4TSI, and is currently produced by Kassel Factory in Germany and Dalian New Transmission Factory in China.
The 7-speed DSG power shift system with dry clutch is the technical core of Volkswagen DSG+TSI plan. The advanced and important point of this transmission is that it can meet the matching needs of all the main models of Volkswagen in the future, from UP, POLO to Magotan, and achieve seamless matching. With the introduction of MQB modular universal platform of Volkswagen Group, DQ200 will shoulder more important responsibilities. When it comes to the similarities and differences between DQ200 and DQ250, we should start with the basic structure of DSG power shift.
20 12 magotan 1.8TSI leading model
Magotan guide price: 19.98-33.48
20 12 sagitar
Sagitar guide price:13.18-18.58
If we want to clarify the problem of DSG, we should start with the technology of these two gearboxes. As we can see from the above picture, DSG powershift has two clutches, which is the origin of the name "double clutch". As shown in the figure, clutch 1 is responsible for 1, 3, 5 and reverse gear, and clutch 2 is responsible for gear 2, 4 and 6; In odd gears, the clutch 1 is engaged, the input shaft 1 works, the clutch 2 is disengaged, and the input shaft 2 does not work, that is, there are always two gears engaged during the operation of the DSG transmission, one is working and the other is preparing for the next step; In manual mode, you can skip and downshift: if the starting gear and the last gear are controlled by the same clutch, the gear controlled by another clutch will be changed; If the starting gear and the last gear are not under the control of the same clutch, you can directly skip and downshift to the specified gear.
With this structure, DSG has the following advantages:
1. The transmission efficiency is high.
2. Fast shifting speed and uninterrupted power.
3. The mechanical structure is simplified and the cost is reduced.
The internal structure of DQ200 and DQ250 is different, but the number of gears is different:
DQ200 is a dry dual clutch, and the torque is transmitted through the friction plate on the clutch driven plate. Because the efficiency of torque transmission of related hydraulic system and dry clutch itself is saved, the dry system greatly improves fuel economy. The 7-speed DQ200 dry dual clutch not only has higher transmission efficiency, but also saves the filter, oil cooler, high-pressure oil pipe and other parts in the gearbox housing. Like ordinary manual gearbox, gearbox oil is only used for lubrication and cooling of gearbox gears and bearings. Therefore, the 7-speed DSG gearbox only needs 1.7 liters of ATF oil, while the 6-speed DSG gearbox needs 6.5 liters of ATF oil. On the other hand, the weight of DQ200 is only 72kg, which is 12kg less than that of Aisin 6AT and 2 1kg less than that of DQ250.
DQ250 is a wet dual clutch, and the torque is transmitted through the friction plate of the wet clutch immersed in oil. Of course, wet dual clutch also has the advantages that dry clutch can't replace. Due to the limitation of torque transmission carrier and working temperature, the maximum torque that dry dual clutch can bear is obviously affected. DQ200 dry DSG gearbox can only be used for engines with maximum torque less than 250Nm. Take Magotan's 1.8TSI engine as an example. The peak torque of the engine 1500 to 4200 rpm is 250NM, which is close to or even exceeds the maximum torque that DQ200 can bear. Obviously, DQ200 is not suitable for this kind of high-power engine (2.0T turbocharged inline four-cylinder engine vs. 2.5V6 and 2.4L).
From the analysis of the problems we have learned so far, the fault points of this 7-speed dual-clutch gearbox mainly focus on overheating protection and excessive wear.
The first is overheating. The same problem occurred in the 6-speed dual-clutch gearbox. Many car owners have changed solenoid valves to solve the problem. So far, there is no official or authoritative person's definite affirmation, so we guess this may be related to the internal temperature rise of the gearbox or the shift procedure.
Daily downshift will cause serious friction of clutch plates. The engine speed soared and a foot of oil was added, but the speed did not increase. At this time, it is obvious that the engine is running at idle speed, and the engine speed drops after the low gear engagement is completed, accompanied by the burning smell of the clutch. Obviously, in this process, it is equivalent to quickly releasing the clutch after the manual gear is in high speed, and the clutch plate is violently rubbed. The heat generated in this process is self-evident.
Secondly, the parking creep characteristics of D gear. We know that the general at model will not give oil even in the D gear, and it will have the characteristic of creeping forward, so that the AT model will not slip when going uphill. This function is realized by the hydraulic torque converter, and the DSG gearbox without the hydraulic torque converter can only achieve peristalsis through the electronically controlled semi-clutch state. Careful car owners will find that DSG gearbox consumes more fuel when braking in D gear than idling in neutral gear, because the power is lost on the clutch.
That is to say, it is not surprising that the clutch plate is always in a semi-clutch friction state when parking in D gear, and the driving force of the engine is converted into heat, which is more serious on the congested road.
Many riders find that the upshift speed slows down after the upgrade procedure.
Third, the handover procedure. At present, the public's solution to DSG fault is to upgrade the software, but the explanation given is a relatively incomprehensible circuit crystallization. And I think the purpose of the upgrade is more related to the wear and tear of the clutch plate, such as:
The initial control program is that when the vehicle starts, the engine speed reaches 1500rpm, and the vehicle speed rises to the second gear at 20km/h ",then when the vehicle is used in congested roads for a long time, the transmission will frequently shift gears between 1, 2 and 3 gears, and when the gear clearance is worn to a certain extent, a gap will occur, but the shift control program remains unchanged, and the gears will shake.
So the public solved it by upgrading the program. For example, the original program setting was that the engine was turned to the second gear at 1500, so now the program is adjusted to 1800 or even higher before shifting gears, so that the gap between shifting gears can be adjusted, thus temporarily making up for the jitter problem. This can also explain why riders generally report that the upgrade is delayed after completing the new program.
For those vehicles with serious problems, that is, the next development of vehicle shake, there will be problems such as jumping and shifting, which can not be solved by upgrading the software program, so Volkswagen adopts the way of replacing the clutch plate or clutch assembly to completely solve the problem.
After reading the above principle and fault analysis, it naturally explains why DSG is less sick in those areas with less congestion. Then why are there fewer problems with the wet dual-clutch gearbox? Because it is full of lubricating oil, the clutch plate is less worn and the clutch has better heat dissipation performance. This will greatly extend the life of the gearbox.
Xiao He beat Xiao He's DSG transmission.
According to the data, Volkswagen's models in China market include Bora, Golf 6, Sagitar and Magotan under FAW-Volkswagen, while Shanghai Volkswagen is LaVida, Xintuan, New Passat, Skoda Ming Rui and Haorui. According to the statistics of China Automobile Industry Association, in 20 12 years, the total sales volume of the above-mentioned vehicles exceeded10.023 million.
Relying on "leading technology", Volkswagen has made brilliant achievements, but there is no doubt that some technologies have made rapid development in DSG. In the face of these millions of car owners, it seems that it is not enough for Volkswagen to appease customers just by extending the warranty period. In addition, in order to make this warranty period effective, the owner must be restricted by many harsh conditions of 4S stores. We hope that the public can give a more sincere and reasonable solution. After all, once it is not handled properly, the storm may start again. For the future, we will wait and see.