This paper elaborated the application trend of mechanical connection technology in automotive Body In White (BIW) manufacturing. Semi-hollow and self-piercing riveting technology as the most widely applied technology of steel aluminum connecting, its process technology parameters are crucial to BIW connection strength. This paper elaborated the semi-hollow and self-piercing riveting process and quality control method as well as 2 common quality defects of semi-hollow self-piercing rivet of BIW in mass production of automobile, analyzed the influencing factors of lack of height and rupture of closed end of rivet. By commissioning of riveting equipment and optimization of riveting process parameters, the above defects were solved, providing solution and direction to solve quality issues in BIW manufacturing.

With aluminum alloy piston of automobile engine as the research object, a thermal insulation performance analysis simulation model of plasma spraying coating was established, the influences of bonding layer material and porosity on thermal insulation performance of coating were analyzed comprehensively, and the thermal insulation performance of coating sample block was verified by test. The test results show that, the thermal insulation coating can significantly reduce the temperature of piston metal matrix, and the thermal insulation performance of ZrO2 thermal insulation layer +NiCrAlY bonding layer is the best. With the increase of porosity of bonding layer, the thermal insulation performance of coating improves, but the mechanical bonding strength between coating and matrix decreases due to excessive porosity, considering the results of thermal insulation and bonding strength, the best material for bonding layer is NiCrAlY, and the best porosity is 10%. After spraying the thermal insulation coating, the equivalent thermal stress value of the piston meets the design requirements of the product under actual working conditions.

Nano-ceramic aluminium alloy is a kind of multi-item solid material, which is based on aluminium or aluminium alloy by physical or chemical methods and composed of one or more reinforcing substances with different properties. This material not only has the advantages of high plasticity of aluminium alloy matrix, but also has the advantages of high hardness and high modulus of reinforcing particles. Therefore, nano-ceramic aluminium alloy has good comprehensive properties and can be widely used in aerospace, electronics and electric, automobiles and other fields. In this paper, a kind of in-situ self-generated nano-ceramic particles in aluminium alloy matrix by chemical method is introduced. The nano-ceramic aluminium alloy prepared by this method has the advantages of light weight, high rigidity, high strength, high fatigue resistance, high temperature resistance, and its mechanical properties are much higher than those of aluminium alloy, while maintaining good processing and manufacturing properties of aluminium alloy.

This article studied the background values of DNPH tubes, with focus on exploring the effects of different brands of DNPH tubes on the recovery rates of formaldehyde, acetaldehyde and acrolein, as well as the impacts of the same brand of DNPH tubes on the recovery rates of different aldehydes, as well as the impacts of sampling conditions on the recovery rates of aldehydes. It was found that different brands have smaller impacts on the recovery rates of formaldehyde and acetaldehyde, but greater impacts on the recovery rates of acrolein. Similarly, different sampling conditions have little impact on the recovery rates of formaldehyde and acetaldehyde, but have significant impacts on the recovery rates of acrolein.

The process design stage for stampings of the Body In White (BIW) is an important stage to improve material utilization rate. This paper elaborated in details methods to improve material utilization rate in the process design stage from 5 aspects, i.e. forming method, process supplement, sheet shape, waste utilization, and thinning rate inspection. There are relatively few studies especially in process supplement. The material utilization rate of stamping parts can be improved by optimizing the distance between the workpiece boundary line and the root of the punch fillet, the width of the drawing management surface, and the drawing parting line, this provides new ideas and approaches for improving material utilization rate.

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.