To meet the product development requirements of a domestic motorcycle enterprise, the bending impact, contact fatigue and single-tooth bending fatigue of 3 kinds of automobile gear steels were tested and compared. The advantages and disadvantages of service performance of those 3 kinds of gear steel were comprehensively evaluated by means of metallography, hardness and fracture surface. On this basis, the application effectiveness of the 3 kinds of gear steels was further verified from the perspective of parts. The results show that the comprehensive mechanical properties, process properties, contact fatigue and bending fatigue of 16MnCr5H are equivalent to those of 20CrMoH, and better than 20CrMnTiH. Therefore, 16MnCr5H can replace 20CrMoH and 20CrMnTiH to manufacture high-load motorcycle gears and meet the performance improvement and application cost performance targets.

During the assembly fatigue bench test of a newly developed light drive axle, the right differential case fractured. Starting from the design and production perspectives, the material, structure, and manufacturing deviations were reviewed using materials analysis, Finite Element Analysis(FEA), and 3D scanning inspection. Finally, it was found that the main cause for the failure of the differential case was the thickness and fillet size at the casting rib plate that were out of tolerance, and the stress concentration occurred after the case was loaded, which eventually caused the entire differential housing break. The differential housing optimized for the main cause passed the assembly bench test successfully.

For the problems of traditional vehicle dimensional breeding mode including unstable critical arm positioning, small measurement range and some stations unable to measure, this paper proposed a novel online matching dimension breeding mode, and analyzed the online matching principle and operating mode. By comparing and analyzing the advantages and disadvantages of the traditional dimension breeding mode and online matching mode, this paper concluded that the online matching model can reduce the difficulty of problem analysis, shorten production preparation cycle of new vehicle model, realize online part measurement of welding fixture, the scientific nature of online matching dimension breeding mode was verified on a new vehicle model project.

The welding line of automotive side wall inner panel was simulated, the PDPS software was used to model the welding line of the automotive side wall inner panel and simulate the production processes, i.e. workpiece loading, fixture open & close, robot welding, workpiece blanking. The simulation research results are as follows, by adjusting the welding gun path or the welding gun attitude, the solder joint accessibility is achieved and collision interference is avoided, adjust the welding process of the welding robot according to the change of the joint value and rotation angle of the 6-DOF manipulator, and control the production time of the production line through the simulation of the production beat of the station operation.

It is difficult to carry out the whole process automation process transformation due to many factors, such as too many assembly elements, too many types of assembly parts, large specification differences and manual operations. To address the above issues, this paper elaborates a whole process automatic tightening process for the body-end support. With Programmable Logic Controller (PLC), PMS (Power production Management System), visual recognition and other software and hardware linkage, and in combination with the actual situation on the site, a set of automatic switching device for bolt tightening sleeves is developed, which realizes automatic tightening of the support under the mode of multiple vehicle models with multiple specifications produced on the same line and ensures that 100% of the quality is achieved.

In order to reduce vibration and noise from central roof in commercial vehicles, 4 reinforcing films were added to the central roof at additional production costs, and the films were easy to fall off after painting. The root cause of vibration and noise in large cover parts is the weak rigidity of the part, the paper therefore proposed to increase the height of the reinforcing rib while meeting the thinning rate requirements. After stamping analysis, prototype production and road test, the final solution to improve the rigidity of the center roof was to increase the height of the reinforcing rib from 3.0 mm to 7.5 mm. The problem of corner cracking in drawing was solved to increase crimping forces and reduce residual stresses. The cost per vehicle is reduced by 45 yuan by eliminating the reinforcing film.

This paper elaborated a variety of states of wave defects of hand buckle sheet metal outside the door of automobile covering parts, deeply analyzed the causes of each state of defects, and proposed effective measures to solve them. A variety of debugging means were summarized, forming a set of methods to quickly solve the wave defects of hand buckle sheet metal, which can expand the idea of solution for future optimization of such defects.

This paper proposed improvement measures and methods to eliminate Volatile Organic Compounds (VOC) pollution inside vehicle through testing VOC in the product and raw material, impact analysis of manufacturing technologies and storage environment. The purpose of this study was to help enterprises carry out low VOC green design and development of automobile roof based on materials, parts and forming process, and provide traceability analysis of automobile roof for automotive OEMs and parts suppliers and solutions to low VOC material process.

This paper studied systematically the factors affecting acoustic absorption and insulation performance of double density felt based on impedance tube method and reverberation-anechoic method. The change rule of acoustic absorbing and insulation properties of flat plate materials were analyzed by impedance tube test with the density, thickness and adding sound insulation film of flat plate materials. The rule of change of the acoustic insulation performance of the molding material with its density and adding sound insulation film was analyzed by reverberation-anechoic test. The test results show that the sound absorption performance can be improved by increasing the surface density and thickness of the plate material without sound insulation film. Increase density to improve sound insulation performance. With the addition of sound insulation film, the sound insulation performance is improved. With the addition of felt density, the sound insulation performance of the plate material is improved, and the sound insulation performance of the molding part has no significant change. The material skeleton of the molding part changes due to the processing technologies, so it is necessary to further study the influencing parameters such as flow resistance and porosity of the sample.

This article elaborated the process layout of the advanced flexible main welding line of Body In White (BIW) for the high beat (60 JPH) 4-model fixed line in a China OEM, this welding line adopted advanced technologies such as automatic welding, automatic pre-assembly, OPEN GATE type main assembly frame, top cover laser brazing, automatic brushing of the top cover laser welding, automatic polishing, robot vision application, AGV automatic conveying, and online measurement, which can meet the requirements of mixed production of different BIW from cars to MPVs. In the high beat production process, the production line can meet the requirements of switching within 4 models without beat loss. The paper firstly elaborated the flexible solution for different stations in the main welding line, then, taking this production line as a case, interpreted the typical processes adopted by some main welding lines in terms of the solution and design of multiple vehicle mixed lines. At the end of this paper, the key points in design and planning of the main welding line were elaborated and analyzed.

This paper compared the difference between laser scanner welding and traditional contact welding, proposed a setting method of robot coordinate system with laser scanner welding optic. This method can shorten modeling time and reduce tooling development cost. Robot virtual tool calibration is different from physical tool. A new calibration method suitable for such virtual tools was developed based on the calibration method of traditional physical tools of robot. This method can shorten process debugging time to eliminate welding seam deviation, rapidly solve tool deviation which frequently occurs in series production, therefore has broad application in automobile production.

In order to improve the automation of the ultrasonic punching process of automobile bumpers, improve personnel efficiency and reduce production costs, the ultrasonic punching process has been upgraded intelligently. Through the innovative design of the ultrasonic punching concave die structure, a visual inspection system and a unified traceability system have been introduced, and the manual coating and quality inspection of traditional primers have been canceled, and the functions of input and traceability of quality and production information have been completed. The integrated operation of bumper ultrasonic punching and coating process has been realized, laying a solid foundation for intelligent manufacturing and digital transformation.