Hottest dual clutch transmission

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The technology of dual clutch transmission

automobile transmission system is developing from manual shift to automatic shift as a whole, especially the high-speed development of computer technology at this stage is applied to the shift transmission system, which makes the automatic transmission technology of the automobile develop rapidly

in recent years, there are three types of automotive automatic transmission: electronic mechanical automatic transmission (AMT), stepless automatic transmission (CVT) and hydraulic mechanical automatic transmission (at). In the field of electronic controlled mechanical automatic transmission, a new transmission mode has emerged in recent years, that is, dual clutch transmission. Because it not only inherits many advantages of ATM and manual transmission, such as simple structure, compact installation space, light weight, high transmission efficiency and low manufacturing cost, but also integrates the good characteristics of at uninterrupted power and rapid and smooth shift, It soon became a new hot spot of research and development in the industry. DCT will change the existing transmission market pattern to a certain extent. In the next few years, the global light vehicle transmission market will compete among at, CVT and DCT

development history and application status of dual clutch transmission technology

the concept of dual clutch transmission (DCT) has a history of sixorseven years. As early as 1939, kegresse A was the first to apply for the patent of the dual clutch transmission, and proposed the design concept of dividing the manual transmission into two parts. One part transmits odd gears and the other part transmits even gears, and its power transmission is connected to two input shafts through two clutches. The passive gears of adjacent gears are staggered to mesh with the gears of the two input shafts. With the control of the two clutches, the transmission ratio can be changed without cutting off the power, Thus, the shift time can be shortened and the shift quality can be effectively improved. The transmission has been tested on trucks. Limited to the control technology at that time, this transmission has not been put into mass production. Subsequently, in the 1980s, Porsche also invented the dual clutch transmission (PDK) for racing cars, but failed to put the DCT technology into mass production

1985, Volkswagen adopted the dual clutch transmission technology on the Audi sport Quattro S1 racing car (see Figure 1), but until the end of the 1990s, with the rapid development of electronic technology, the dual clutch control technology gradually matured. Volkswagen and borgwana first cooperated to produce and put it on the mass production mainstream model Audi, It is named direct shift gearbox (DSG). This technological innovation was first demonstrated to the world in 2002. In 2003, the company launched a 6-speed DSG transmission, becoming the first complete vehicle manufacturer to provide a dual clutch system. In 2006, Volkswagen took the lead in applying DSG transmission to Audi TT 3.2 model, and then DSG products were successively supplied to Volkswagen Jetta, Volkswagen Touran, Volkswagen fifth generation Golf, Volkswagen Bora, Audi A3, Audi TT, seat, Skoda and many other models. At present, it has set a sales record of more than 1million pieces. Recently, Volkswagen is code named DQ200 transmission, which uses a pair of dry clutch plates to replace the original 6-speed DS. It also gave birth to a series of technical innovation of polyurethane in the automotive industry. The liquid regulated dual clutch plates of G transmission have significantly improved its shift efficiency and power transmission (see Figure 2 and figure 3)

as one of the actual developers of innovative transmission, Porsche, the top professional sports car brand in Germany, will launch its self-developed dual clutch transmission called "PDK" (Porsche doppel kupplungen - German for dual clutch transmission system)

after the advent of Volkswagen DSG transmission, Volvo and BMW also successively joined the camp of dual clutch transmission and launched their transmission products with similar concepts. BMW recently released the research and development results of dkg seven speed dual clutch transmission, and decided to use this technology in the BMW M3 series first. It is called "M-DCT". The biggest difference between BMW seven speed automatic transmission and Volkswagen's latest seven speed automatic transmission is that "M-DCT" dual clutch adopts wet clutch, while Volkswagen's dual clutch adopts dry clutch

recently, Fiat also officially announced that its self-developed dual clutch transmission system will be released in 2009. This transmission, named c635, is equipped on many Fiat models, including Grande Punto, Bravo and Alfa Romeo. It will be available in 2010

SAIC's own brand automobile Roewe will launch a model with DSG dual clutch transmission in cooperation with BorgWarner before 2010. According to SAIC's plan, Roewe 750 1.8T and Roewe W261, which will be launched in 2009, are most likely to become models equipped with borgwana DSG dual clutch technology

in a word, although Volkswagen and other manufacturers have launched dual clutch transmissions, the core dual clutch control modules are all from Borg Warner

structural features and working process of dual clutch transmission

structural features

dual clutch transmission is composed of a dual clutch device composed of two clutches, a three-axis gear transmission system based on manual transmission, an automatic shift mechanism and an electronic control hydraulic control system. The input shaft assembly is a double drive input system composed of a solid shaft and its external sleeve shaft. The transmission gears of odd gear and even gear are respectively arranged on the two input shafts (see Figure 6). Clutch 1 is connected with solid input shaft to control odd gear, and clutch 2 is connected with sleeve (hollow) input shaft to control even gear. The two clutches transmit power to the dual drive system in turn

the power output shafts are also different. One output shaft realizes the power output at low gear, and the other shaft realizes the power output at high speed and reverse gear. The power of the two output shafts should be linked with the final output shaft of the transmission to transmit the power to the wheels. In addition, the traditional arrangement method is not adopted for the arrangement of the transmission gear set, and the arrangement of the transmission gears is not arranged in the order of gears, In this way, the speed change gears of two adjacent gears will no longer share a synchronizer, which provides a technical guarantee for the seamless transmission of power. The structural layout is shown in Figure 5

working process

when the car starts driving in gear 1, the clutch 1 that controls the input of odd gear is connected to make the solid input shaft connected with odd gear rotate, and the synchronizer of gear 1 will automatically mesh with the gear of gear 1 on the output shaft of low gear to realize linkage with the output shaft of low gear. The power transmission route is shown by the solid line and arrow in Figure 6 (a). There is a helical gear at the end of the low-speed output shaft, which outputs power to the differential and then transmits it to the final output shaft. While the 1st synchronizer is meshed with the 1st gear, the 2nd synchronizer is also meshed with the 2nd gear under the control of the electronic control assembly and is in the working standby state. Looking at the power transmission route of the second gear, when the transmission is shifted to the first gear, the clutch 2 controlling the input shaft of the even gear is disengaged, so it is completely disconnected from the engine power at this time, as shown by the dotted line and arrow in Figure 6 (a). At this time, although the sleeve (hollow) input shaft connecting the even gear will also rotate under the drive of the second gear, it is completely rotating with the gears of other odd gears, There is no power output, just to prepare for next upshift. Therefore, the input shaft of even gear will not interfere with the power of the input shaft of odd gear, and the output shaft of high gear will also follow the rotation, but it is also in idle state, without any power output, so there is no mutual interference in the power output

when the transmission enters the second gear, when the first gear clutch is stepped down to exit the first gear, the clutch 2 is connected, and the second gear is engaged as shown by the solid line and arrow in Figure 6 (b). At the same time, the third gear is pre combined as shown by the dotted line and arrow in Figure 6 (b). This continuous operation makes the transmission have no clearance when entering and removing the gear. Therefore, during the operation of DCT transmission, two gears are always combined, one is working, and the other is ready for the next step. Under the control of the electronic control unit, the clutch controlling the even gear is combined with the power output end of the engine, and the clutch controlling the odd gear input shaft is disconnected from the output end of the engine to complete the power switching of the input shaft. In this process, the two clutches are completely synchronized, instead of the traditional single clutch transmission, when the clutch is disconnected from the power output end of the engine, Power interruption may occur during the test process. When the second gear power switch is completed, the synchronizer controlling the third gear will also mesh with the third gear box under the control of the electronic control components, so that the transmission gear of the third gear is in the standby state

in addition to the DSG will make the higher gear in standby state during upshift, the CDW (6) 0 type impact test low-temperature tank series is a newly developed tightening mechanism cold equipment according to the requirements for low-temperature devices in gb/t229 (metal Charpy Notch Impact Test Method) (1994). In addition, it can also achieve standby state for downshift and speed up downshift time during overspeed

dct's prospect analysis in the domestic market

since DCT is developed based on parallel shaft manual transmission, it inherits the advantages of manual transmission such as high transmission efficiency, compact installation space, light weight and low price. At the same time, it also has the characteristics of excellent starting and shifting quality of automatic transmission, and has broad development prospects and significant advantages in popularization and application, It is mainly manifested in the following aspects:

dct is almost not limited by power transmission, and can be widely used in various vehicles

dct has low production cost

since DCT is developed based on manual transmission, power transmission still depends on clutch and gear. The manufacturing technology of gear transmission parts in China is relatively mature, and most transmission manufacturers have a certain technical foundation. It provides conditions for the development of DCT technology

dct production equipment can be used by slightly modifying the existing manual transmission production line. Therefore, for the manual transmission manufacturer, the product upgrading process has a short cycle, less new investment and good production inheritance

due to the wide range of transmission demand, the application of DCT Technology (gear transmission technology + automatic control technology) will not only be limited to automobile transmission, but also produce the same application effect in other transportation machinery industries

China's automobile industry started relatively late, and most production lines at this stage are mainly producing manual transmission. Today, the automatic transmission is in a high growth period, and the automatic transmission of domestic vehicles mainly depends on imports. Therefore, the development of DCT products will certainly play a positive role in improving the independent development ability of China's automatic transmission. At the same time, it also adapts to China's industrial base. (end)

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