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Differences between traditional cold forging and cold orbital forging of a spur bevel gear

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Procedia Engineering 2017年 207卷 442-447页

作者： Wuhao Zhuang Xinghui Han Lin Hua School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Hubei Key Laboratory of Advanced Technology of Automotive Components Wuhan University of Technology Wuhan 430070 China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of Technology Wuhan 430070 China

Cold orbital forging, as an advanced incremental forming process, has been widely researched and used to fabricate the spur bevel gear. However, the mechanism of cold orbital forging is quite different from that of traditional cold forging, which leads to the different forming laws and different properties of forged gear. In this paper, cold orbital forging and traditional cold forging of a spur bevel gear are simulated under the same conditions in the Deform-3D software platform. The filling process, geometric characteristics of forged gear, effective stress distribution, effective strain distribution, gear tooth accuracy are comprehensively clarified and compared. The results show that, comparing with traditional cold forging of a spur bevel gear, cold orbital forging can increase the degree and homogeneity of plastic deformation and improve the gear tooth accuracy.

关键词： Cold orbital forging Traditional cold forging FE simulation Spur bevel gear

Enhancement of Compressive Behavior and Energy Absorption of a Skull-Inspired Lattice Structure for Suppressing Shear Bands

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SSRN 2024年

作者： Zhu, Yifan Xu, Fengxiang Niu, Xiaoqiang Zou, Zhen Liu, Zhengpao Hubei Key Laboratory of Advanced Technology of Automotive Components Wuhan University of Technology Wuhan430070 China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of Technology Wuhan430070 China

Lattice structures have been widely applied as bearing and energy absorption components in vehicles, construction, aerospace, and other engineering fields. Under axial compression, shear bands in strut-based lattice structures will cause stress drop, resulting in the weakening of bearing and energy absorption capacities. The only way to suggest a method for suppressing shear bands is to elucidate the formation mechanism. In this study, we have proved through experiments, finite element (FE) analysis, and theoretical calculation that the internal stress on strut-based 45° sections is the source of shear stress that results in shear bands, with the maximum shear stress occurring at the strut edge of the 45° diagonal section. Inspired by the spongy bone structure of the skull, this study presented the tangent arc bend strut (TABS) lattice structure, which only allows internal stress to pass in the vertical direction and limits the formation conditions of shear bands. The compression experiment results demonstrate that TABS design lessens the constraints of the lattice structure cell, achieves internal force conduction in the vertical direction, and suppresses the formation of shear bands. Furthermore, the lattice structure is enhanced by 32.71% plateau stress and 23.88% specific energy absorption (SEA). Dynamic compression experiments demonstrate that TABS lattice structure has excellent structural and deformation stability at medium and high compression speeds. This study offers a fresh avenue for improving the stable bearing and energy absorption capacity of lattice structures. © 2024, The Authors. All rights reserved.

关键词： Energy absorption

A Novel Gear Defect Detection Method Through Improved Yolov5 Network Using Attention Mechanism and Feature Fusion

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SSRN 2022年

作者： Zhang, Shuwen He, Minqi Zhong, Zhenyu Zhu, Dahu Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology Wuhan430070 China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of Technology Wuhan430070 China

This work is motivated by the misdetected and undetected errors in metallic gear defect detection when the defect features are very close to the interferences of oil stains and image shadow. In this paper we present a novel gear surface defect detection method based on the improved YOLOv5 network model to solve this problem. The presented method combines the approach using the attention module CBAMC3 constituted by CBAM and C3 modules together with the analysis of the module BiFPN_concat, which makes the network capable of extracting and fusing defect features, respectively. The cosine annealing function is then employed to improve the learning ability of the network by modifying the learning rate. The experimental results indicate that the improved YOLOv5 network enhances both the recall rate by 13.1% and the mAP@0.5 by 12% based on the constructed gear defect dataset compared with the original YOLOv5 network. © 2022, The Authors. All rights reserved.

关键词： Feature extraction

Influences of key forging parameters on gear-tooth deviation of cold forged spur bevel gear

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Procedia Manufacturing 2018年 15卷 504-510页

作者： Wuhao Zhuang Lin Hua Xinghui Han School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 China Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology Wuhan 430070 China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of Technology Wuhan 430070 China

An elastic-plastic FE simulation model is proposed to predict the evolution of gear-tooth deviation in cold forging of a spur bevel gear, and the reliability of this FE model is verified by experiment. Then, the influences of the interference value of die shrink fitting, the forming degree of a preformed billet and the friction factor on the tooth thickness error and the shape error of the tooth surface were investigated comprehensively. The results show that, he forming degree of the preformed billet has the most significant influence on the gear-tooth deviation, the interference value of die shrink is secondary, and the impact of friction factor is slight.

关键词： Spur bevel gear Cold forging process Accuracy FE simulation Deformation

Techniques used to improve the tribological performance of the piston ring-cylinder liner contact

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Techniques used to improve the tribological performance of t...

第二届先进电子材料、计算机与材料工程国际学术会议（AEMCME 2019）

作者： Ahmed Elagouz Mohamed Kamal Ahmed Ali Hou Xianjun Mohamed A.A.Abdelkareem Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of Technology Automotive and Tractors Engineering Department Faculty of Engineering Minia University Hubei Collaborative Innovation Center for Automotive Components Technology

The mechanical assemblies in automotive engines are usually lubricated by a combination of oil and solid lubrication films. Consequently, the significant current challenges for developing the tribological behavior of vehicle engines need the lubricants that conform to different operating conditions by providing mechanisms for reducing friction and wear. This article summarily reviews the techniques used to improve the tribological performance for piston ring-cylinder liner contact and evaluates their effectiveness to provide the most assuring approaches to reduce friction and wear. The objective was to explore the areas where there are openings for further research contributions to achieving an improvement in the piston ringcylinder contact in automotive engines.

关键词： Techniques used to improve the tribological performance of the piston ring-cylinder liner contact

Numerical Investigations on a Thermoelectric Generator Based on Diesel Engine Integrated Doc+Dpf+Scr Aftertreatment

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SSRN 2024年

Thermoelectric technology improves engine energy efficiency by recovering waste heat from the exhaust gases of internal combustion engines. Compared to a conventional Thermoelectric Generator (TEG), TEG integration in engine aftertreatment can improve power generation and reduce TEG impact on engine back pressure. In the current study, a three-dimensional numerical model of TEG based on an integrated aftertreatment for diesel engines is proposed for the first time and the related research is carried out using numerical simulation. The results show that the exhaust temperatures and exhaust gas compositions corresponding to the three operations have a strong influence on the hot side temperature, and the heat in the non-near-wall region of Diesel Oxidation Catalyst (DOC) and diesel particulate filter (DPF) is limited by the low thermal conductivity of the porous medium carrier. UWS has a certain cooling effect on the high temperature exhaust gas. The location of DOC has a significant effect on the performance of the TEG, and TEMs located near DOC are subjected to the effects of the chemical reaction heat and the porous medium. It is of great significance to improve energy efficiency and reduce environmental pollution through the rational use of TEG in diesel-engine vehicles under current and future emission regulations. © 2024, The Authors. All rights reserved.

关键词： Diesel engines

A Novel Gear Defect Detection Method Through Improved Yolov5 Network Using Attention Mechanism and Feature Fusion

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SSRN 2022年

This work is motivated by the misdetected and undetected errors in metallic gear defect detection when the defect features are very close to the interferences of oil stains and image shadow. In this paper we present a novel gear surface defect detection method based on the improved YOLOv5 network model to address this problem. The presented method combines the approach using the attention module CBAMC3 constituted by CBAM and C3 modules together with the analysis of the module BiFPN_concat, which makes the network capable of extracting and fusing defect features, respectively. The cosine annealing function is then employed to improve the learning ability of the network by modifying the learning rate. The experimental results indicate that the improved YOLOv5 network enhances both the recall rate by 13.1% and the mAP@0.5 by 12% based on the constructed gear defect dataset compared with the original YOLOv5 network. © 2022, The Authors. All rights reserved.

关键词： Feature extraction

Optimized Yolov5 Algorithm for High-Precision Inspection of Surface Defects in Aluminum Profiles

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SSRN 2024年

作者： Fang, Tengyuan Xu, Fengxiang Zeng, Chao Zou, Zhen Hubei Key Laboratory of Advanced Technology of Automotive Components Wuhan University of Technology Wuhan430070 China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan University of Technology Wuhan430070 China

To address the critical need for aluminum profile surface defect detection in industrial production, a detection method based on an improved YOLOv5 was proposed. The Selective Kernel Attention (SKA) module was introduced to adaptively select receptive field information and alleviate information redundancy. The Switchable Atrous Convolution (SAC) module was introduced to further enlarge receptive field information, achieve multi-scale feature extraction, and enhance the model's feature extraction capability. Considering computational cost issues, the model was pruned using the Performance-Aware Global Channel Pruning (PAGCP) method. Experimental results showed that the improved YOLOv5 model achieved a 2.7% increase in mAP compared to the baseline. After pruning, the number of model parameters and weight file size decreased by 58.5% and 57.1%, respectively, while FPS increased by 41.2%, and the mAP@0.5 metric did not significantly decrease. Defect detection experiments further validated that the proposed method meets the actual industrial production requirements. © 2024, The Authors. All rights reserved.

关键词： Surface defects

Morphology of iron-zinc coating for hot press forming steel

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Morphology of iron-zinc coating for hot press forming steel

Chinese Materials Congress on Methods of Design and Characterization of Materials, Research and Development of Technological Processes, 2015

作者： Fang, Fang Hu, Kuanhui Wei, Haili Chen, Yiming Huang, Feng Research and Development Center Wuhan Iron and Steel Co. Wuhan430080 China Manufacturing Department Wuhan Iron and Steel Co. Wuhan430080 China Hubei Key Laboratory of Advanced Technology of Automobile Parts School of Automotive Engineering Wuhan University of Technology Wuhan430070 China

ISBN: (纸本)9783038357629

The coating morphology of a hot press forming steel galvanealed by HDPS (hot dipping process simulator) in laboratory was studied in the paper. The results show that, firstly from thermodynamic calculations, the intermetallics increased the melting point of Zn, and it is possible to avoid the melting and volatilization of zinc coating for hot press forming steel strip, when the coating mainly consists of δ phase (~10% Fe) in galvanealing process, and lower re-austenization temperature (below 782°C) in hot press forming process. Secondly, according to the SEM morphology in the paper, the zinc coating formed an alloy predominantly composed of delta (δ) phase, a low iron zeta (ζ) phase formed on the surface, and a high iron gamma (Γ) phase formed at the interface with the steel substrate. The hard and brittle Γ phase failed to grow up on the interface of coating and matrix which results in high shear stress and good coating adherence. © 2016 Trans Tech Publications, Switzerland.

关键词： Zinc coatings