From September 18 to 20, 2019, the 7th China Lightweight Car Body Conference, hosted by China SAE and the China Auto Lightweight Technology Innovation Strategic Alliance, was held during the 13th Automotive Lightweight Congress & Exhibition, when the Best Vehicle Model Award went to Dongfeng Aeolus Yixuan, the Excellent Vehicle Model Award went to ARCFOX U5, the Vehicle Model Innovation Award went to GWKULLA R1, FAW HS5 and BAW Zhidao. Specially, Dongfeng Aeolus Yixuan is analyzed as follows:

v  Vehicle Model Introduction

Dongfeng Aeolus Yixuan, is the first domestic vehicle model built on the CMP platform which is jointly developed by Dongfeng and PSA. The car has an overall length of 4, 640mm, an overall body width of 1,800mm, an overall body height of 1,660 mm and wheelbase of 2, 660mm. With fastback sedan car shape and sharp outlines, its vigorous and fashionable style is shaped. The trim is characterized with an encircling capsule, a high-tech full floating touch screen and an advanced intelligent connected system. In terms of power system, a 1.5T turbocharged engine is equipped with a maximum power of 110kW/5500rpm and a maximum torque of 230N·m /1800-4000 rpm. Besides, Yixuan is equipped with the L2+ intelligent assistant driving system and Windlink 4.0 artificial intelligence control system, which are the leading technologies in the industry.

v   Vehicle Model Analysis

 Yixuan's car body is built on the CMP platform, on which more than 10 methods including advanced materials and technologies, lightweight structure and improvement of torsional rigidity are applied to achieve lightweight design. The weight of the body-in-white is 285.6kg, the torsional rigidity is 21, 591 N?m /deg, and the lightweight coefficient is 3.2.

Dongfeng Aeolus Yixuan Body-in-White

In terms of materials, the high-strength steel is applied more with its ratio increased to 68%; the third generation of high-strength steel TD1080 was applied for the first time; the material of reinforcement longitudinal beams of the left and right channel is replaced by TD1080, which can reduce the weight by 1.36kg; the left and right edge stringer adopt MS1500 rolling material, which greatly improves the side impact safety and reduces the weight by 0.83kg; light metal materials is used to reduce weight, Yixuan's front anti-collision beam adopts aluminum profile extrusion technology, which has better impact energy absorption performance and weighs 2.5kg lighter than steel beams of the same size; weight reduction is attained through composite materials, the front end module of Yixuan adopts PA6 composite materials to replace the traditional steel water tank frame assembly, and the weight is reduced by 2.3kg, which not only achieves the purpose of weight reduction, but also realizes modular assembly and improves the loading efficiency.

Technically, the cage car body is optimized in structure and reduced in weight through a new manufacturing process. On the premise of ensuring safety performance, the A and B columns, the front seat crossbeam and the pedal crossbeam are thermoformed, and the threshold part is rolled with ultra-high strength steel over 1000MPa. The front longitudinal beam and the front baffle crossbeam adopt laser tailor welding technology. Yixuan car body uses 18 thermoformed parts and 5 ultra-high strength steel rolled parts. The weight is reduced through variable thickness thermoforming manufacturing process, and the rear longitudinal beam of Yixuan car body adopts uniform variable thickness thermoforming process, which ensures the strength requirement of the rear torsion beam mounting point, and realizes weight reduction. The application of these new processes enables the car body performance to meet the target requirement, weight reduction of 21.12Kg.

In terms of structural optimization, according to the requirements of the structural strength of the car body, a large number of high-strength steel plates with different grade requirements are adopted in parts apart from the outer covering parts, ultra-high-strength steel plates and thermoformed materials are adopted in key structural parts, and the application of high-strength steel plate materials reaches 68%, which ensures great car body performance, reduces weight by 19Kg, and improves fuel economy.

In joining technology, spot welding, arc welding, bolts and structural adhesive are used as the main techniques. Particularly, the spot number of spot welding is 4, 265, length of arc welding is 4.17m, the number of bolts is 46, and the length of structural adhesive is 22.68m.

(The above information is provided by the organizing committee of Automotive Lightweight Congress & Exhibition  )