Chery often shows the image of "science man", but in the automotive industry, anyone who can create industrial products will only be a weak scholar. As a result, Chery started the "National Technology Tour" with Kunpeng DHT hybrid technology, and although DHT technology is blooming everywhere now, Chery still plays very well in its own way.
First of all, what is DHT?
Before that, we're going to start with Pangu Kaitian. In the era of the internal combustion engine, it only takes three steps to drive the vehicle: engine output - clutch transmission - transmission of the transmission, and the car moves.
If you want to improve performance, it is nothing more than to improve the engine or transmission, so with the upgrading of materials science, we have come to the golden age of the car, and countless bold and brave attempts have left tearful works.
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The change of the times is often because of the inner coil, today's internal combustion engine acceleration slows down, the great power game and carbon limit, the motor as another kind of human play of the most slippery drive unit, is combined into the automotive products.
Things always start with 0, 1, 2, so the earliest hybrid configurations were all single motor arrangements, which could be named after PX (P1, P2, P3, P4) at any of the three traditional nodes of the engine/clutch/gearbox, depending on the location.
But no matter where the single motor is placed, there are regrets, at this time the engineers pull out the second motor and start the whole work.
The first is the tandem scheme, which, as the name suggests, means that the different power units have a strict transmission sequence, 1-2-3, that is, the engine only generates electricity and the motor drives the vehicle.
This scheme allows the engine to completely avoid the low efficiency range, but also avoids the high efficiency range, and the overall conversion efficiency is not as good as pure electricity, especially under high power loads. Therefore, mature brands will not invest in this configuration, and the ideal one can rely on this solution to cut into the market is actually a typical case of demand overcoming technology.
That series (parallel) is not OK, just confuse the connection, that is, the link between the engine and the motor and the gearbox, which can be connected at the same time or separately. There is no shortage of ingenious designs under this architecture, such as the Honda i-MMD hybrid system, which matches the optimal power scheme for different power requirements.
This scheme, Sheng Honda's engine itself is good enough, the drive structure is simple and reliable, and the logic is clear. If you pick a fault, it is that this so-called e-CVT, in fact, is not a "gearbox", but a clutch-controlled corresponding engine / motor two power input and output power shunt device, it only has a fixed gear ratio gear, only connect / disconnect two states, according to the transmission ratio is about 6 gears of the traditional transmission, so the parallel mode of the intervention speed is 70km / h, in order to ensure efficient working area.
Along this line of thinking, DHT technology comes: Dedicated Hybrid Transmission, which is not a new hybrid architecture, but a dedicated gearbox for more complex power matching of hybrid systems, with -gear-position.
In fact, the earliest official presentation of DHT technology was at the CTI Berlin Forum in 2016. This technology is indeed a technology to further promote the excellent hybrid architecture and avoid hybridization becoming an additional subsystem of the fuel system.
From today's domestic situation, everyone can also guess that DHT technology is actually the national team behind the promotion of independent brand technology competition. The background is a test question issued by the state during the "13th Five-Year Plan" to "14th Five-Year Plan" period for the "dual motor coupling DHT hybrid system", the purpose is to further complete the task of energy conservation and emission reduction.
There were more than a dozen students participating, of which five had already submitted papers: BYD DM-i (mass-produced), Great Wall Lemon DHT, GAC Green Engine Hybrid II, Chery Kunpeng DHT, Dongfeng Mach DHT, and several others were writing books: Wuling, Geely, BAIC, FAW, Changan, SAIC.
The five companies that have already been mass-produced have some common points, such as the use of flat wire windings in the motor, the oil-cooled high-speed high-density motor, and the engine uses the Atkinson cycle special engine or the deep Miller cycle engine to improve efficiency.
Back to Chery Kunpeng DHT, how to improve the score under the same roll, Chery chose to show skills. In a word, it is a "slightly earthy technical slogan" composed of three numbers: 3 gears, 9 modes and 11 speeds.
Compared with other technologies, Chery uses three speed ratio settings to cope with the combination of one engine and two motors through arrangement and combination. Big logic, in fact, like all hybrid systems, is to let the motor and engine crossover to cover all the efficient intervals, the difference is that the three gears can make the matching more complex, this complexity is a double-edged sword, it means that the difficulty of the control system and the upgrade of control capabilities.
9-mode 11-speed is based on structure-based application matching, according to different scenarios, matching the best power solution. Among them, the No. 1 small power motor also plays the role of a generator in addition to driving, and the No. 2 high-power motor located in the gearbox is only responsible for driving. Since this complex mechanism can couple and decouple three power sources with three gears, there is a lot of room for the development of control strategies in the hardware structure.
Obviously, this structure belongs to the dojo in the shell of the snail, the original DHT is a more complex and precise special transmission for the hybrid system, and on this basis increased to 3 gears, in addition to the high requirements for the control system, the durability and reliability of each component is also an important part of the practical value of the construction of this whole system.
Finally, we post some official data for you to have some reference for the performance of this system: the highest 510N·m maximum input torque, the engine can also be accelerated at the lowest intervention point of 20km/h according to the actual road conditions, and the four-wheel drive version has zero hundred acceleration
Under the impetus of the policy, domestic DHT technology will enter the outbreak period, and the hybrid technology of each brand is bound to collide head-on with joint ventures and foreign-funded technologies in the market, unlike the previous sporadic offensive, this time it can be said that in addition to competition, there is also a relationship between the various independent brands to open up the domestic hybrid market.
Which independent brand are you more optimistic about? Leave a message to tell us ~
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