To avoid the risk of incorrect parts, incorrect positions, incomplete or missed assembly during the production process of automobile final assembly, a final assembly error-proof system is established from 4 dimensions: design, process, logistics, and management. The working principles and application points of error-proof sub dimensions such as product generalization, structural error-proof, color error-proof, identification error-proof, process route error-proof, process card annotation, code scanning error-proof, intelligent tightening system, industrial vision system, SPS logistics mode, intelligent lighting system, BOM management, breakpoint management, etc., are elaborated and illustrated. It is pointed out that the combination of various dimensions is necessary to achieve good error-proof effects.

In this research, a new flexible automation technology is adopted to achieve full process automatic production of light truck longitudinal beam. According to the electrophoretic process requirements of longitudinal beam parts, combined with the product characteristics of longitudinal beam cross-section, by using the automatic transportation system to connect the punching machine, cutting machine, forming press and automatic hanging rack, this paperaims to achieve the automation and intelligent production of light truck longitudinal beam at the entire process from sheet metal to forming and hanging. This method has been successfully applied to the actual production in a commercial vehicle in China. After trial production verification, automation level, production efficiency, and cost operation control have been significantly improved compared with traditional production methods.

This article firstly introduces the current situation of the evaluation of robot usage status, and then proposes a method of evaluating robot operation status based on the time dimension, and presentes the concept of robot utilization rate as well as the visualization display method. A robot running time acquisition method based on big data and industrial internet is introduced, and a corresponding algorithm is designed to process the acquired data. Moreouer, the cycle operating time reflecting the actual operating state of the robot is calculated, which as displayed visually. Finally, combined with specific cases, the value of visualization of the robot utilization rate is introduced. By comparing the utilization rates of robots at different stations in the same production line or in different production lines, this paper provides optimization direction for the production line cycle time and production capacity promotion.

In order to improve the lightweight degree of the whole vehicle, according to the equal strength principle and iterative optimization method, a lightweight new energy tractor frame is designed by using 6082-T6 aluminum alloy extrusion and referring to the structure of steel frame. Through finite element modeling and simulation, simply supported beam simulation calculation, multi-channel bench simulation analysis and physical bench test, the static strength, bending stiffness, torsional fatigue strength performance are verified. The minimum safety factor of static strength of the final frame scheme is 1.11, the bending stiffness is 1.06×10¹³ N/mm, and the torsional fatigue test has not failed for 400 000 times. The results show that the newly designed frame of new energy tractor can meet the performance requirements and reduce weight by 40% on the basis of steel frame.

In this paper, corrosion properties of 3 heat treatment-free die casting aluminum alloys to 2 typical integrated die casting die steels are studied through dynamic rotary immersion test in molten aluminum alloy. The results show that after 20 min rotary immersion test, die steel samples in 1# molten aluminum alloy has the smallest corrosion area and mass loss. As a result, 1# aluminum alloy has the smallest die soldering tendency. Therefore, in the application of new heat treatment-free material, it is important to choose a die material which fits well with this heat treatment-free die casting aluminum alloy to obtain the smallest corrosion mass loss, and ensure the service life of die.

Failure analysis of the 34MnB5 hollow stabilizer bar fracture occurred in the road test of a mass production vehicle was carried out using laser confocal microscopy, scanning electron microscope and other equipment. It was confirmed that the insufficient shot blasting process time and the existence of axial original cracks caused early fatigue failure and fracture of the stabilizer bar. In order to further clarify the root cause of the failure and fracture, this article investigated and analyzed the manufacturing process of the stabilizer bar, determined that the main cause for the fracture of the stabilizer bar was insufficient shot blasting time, thus evaluated the subsequent impact of this fracture failure accident. Finally, the article identified the direction of rectification for the risk points during the investigation process, and proposed optimization measures to further prevent the occurrence of such problems.

In order to reduce stamping cost from perspective of material cost control, this article discussed the cost control strategy for automotive stamping material from three aspects: improving material utilization rate, applying new sheet metal manufacturing processes, and selecting materials rationally, combined with specific application cases. Firstly, material utilization can be improved by product collaborative development, stamping process optimization, and reusing stamping waste materials. Secondly, in the application of new sheet metal manufacturing processes, processes such as roller pressing and integrated heat forming can be used to replace the process of single stamping or multiple separate stamping followed by spot welding. Finally, in terms of rational material selection, principles for selecting steel with the same strength, using bake-hardening steel instead of interstitial-free steel, and recommendations for the application of high-strength steel are provided.

The effects of pre-strain and baking on the microstructure and mechanical properties of QP980 cold rolled sheet were studied by means of universal tensile testing machine, pendulum impact testing machine, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). The results show that with the increase of pre-strain, the ultimate bending properties and impact properties of QP980 cold rolled sheet decrease After baking at 170 ℃ for 20 min, the impact properties of the material increase, and the Bake Hardening (BH) properties increase with the increase of pre-strain; X-ray diffraction analysis shows that baking does not cause phase transformation, and the carbon content in residual austenite decreases; Scanning analysis shows that the ductile fracture area in the impact fracture increases significantly after baking treatment.

As the pace of product updates accelerates, the flexible roll forming process has garnered widespread attention within the industry. However, due to the inherent complexity of its forming process, inevitable defects arise. To address this, numerical simulation and analysis of the forming process of variable cross-section panels along a three-point bending curve were conducted, examining the impact of material, thickness, and flange height on warping. The results indicate that the warping defect in the panels is related to longitudinal strain, with the minimum warping defect occurring when the longitudinal strain distribution is uniform. Orthogonal simulation design analysis determined the primary and secondary order of process parameters affecting warping height as thickness, flange height, and panel material. The conclusion is that compared to aluminum alloy materials, the warping height is reduced when using high-strength steel with a high yield strength ratio, whereas the warping height increases when using high-strength steel with a low yield strength ratio.

As a new type of ultra-fine grained high-strength steel, UF340 has the potential to replace HC180BD in automotive exterior panels. This paper investigated its mechanical properties and formability. The results indicate that UF340 and HC180BD have similar mechanical properties in terms of plasticity, processing hardening index, and anisotropy, but UF340 does not exhibit significant bake hardening properties. The formability of the two materials is similar. There is certain difference between the forming limit curve calculated by the Keeler model and the forming test results. The forming limit diagram obtained by linear segment fitting data has a higher degree of agreement with the experiment, the forming limit curve obtained by this method can provide a reference on the forming application of new materials.