Process Study for Forming a Precise Spline

2014 ◽  
Vol 915-916 ◽  
pp. 323-326
Author(s):  
Seong Sik Lim ◽  
Deog Jae Yoon ◽  
Geun An Lee ◽  
Ho Joon Choi ◽  
Yeon Ku Kim ◽  
...  

A tubular shafts have been considered for weight reduction and high quality in the automobile industry. However, in the case of long and thin tubular shafts, it is very difficult to form an internal spline under a cold extrusion process due to folding and buckling. In this study, multi-stage forming is applied to form precise teeth shape in a long and thin tubular shaft. The effects of die diameter and thickness of the material are investigated and analyzed to determine the number of processes based on a FE simulation. Extrusion experiments have been performed to verify the results obtained in the FE simulation. It is confirmed through these tests that a long spline shaft with high dimensional accuracy and improved mechanical properties is formed.

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 69
Author(s):  
Jae-Hong Kim ◽  
Jae-Chang Ryu ◽  
Woo-Sik Jang ◽  
Joon-Hong Park ◽  
Young-Hoon Moon ◽  
...  

The multi-stage roll die forming (RDF) process is a plastic forming process that can manufacture a transmission part with a complex shape, such as a drum clutch, by using a die set with rotational rolls. However, it is difficult to satisfy dimensional accuracy because of spring-back and unfilling. The purpose of this study is to design a multi-stage RDF process for the manufacturing of a drum clutch to improve dimensional accuracy using an artificial neural network (ANN). Finite element (FE) simulation of the multi-stage RDF process is performed to predict the dimensional accuracy according to various clearances for each stage. Moreover, the ANN is used to determine the relationship between the clearance and dimensional accuracy of the drum clutch to reduce the number of FE simulation. The results of the FE simulation and ANN are used to determine the optimal clearance for each stage of the RDF process. Finally, the drum clutch is fabricated using the determined conditions. The experimental results are in good agreement with the results of FE simulation from the aspect of outer diameter, inner diameter, thickness of outer tooth, thickness of inner tooth, and face thickness of tooth.


2022 ◽  
Vol 2160 (1) ◽  
pp. 012055
Author(s):  
Yuhong Yuan ◽  
Yu Ren ◽  
Quan Wu

Abstract In order to solve the flange and dent defects in the end face of the cold extrusion of the connecting screw, the Deform3D software is used to simulate the extrusion forming process of the connecting screw, and the velocity vector is used to study the metal flow law of the part in the cold extrusion process. According to the velocity field and deformation law obtained by the simulation, the end face depression defect in the forming process is predicted. An improved production process is proposed, and the simulation results show that the new process scheme effectively eliminates the “sag” defect on the end face of the part. Finally, the extruded parts with qualified dimensional accuracy are obtained through experiments, and the results are basically consistent with the simulation results.


Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 580
Author(s):  
Francisco J. G. Silva

Though new manufacturing processes that revolutionize the landscape regarding the rapid manufacture of parts have recently emerged, the machining process remains alive and up-to-date in this context, always presenting itself as a manufacturing process with several variants and allowing for high dimensional accuracy and high levels of surface finish [...]


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Jin Chen ◽  
Tianyuan Chen ◽  
Yifei Song ◽  
Bin Hao ◽  
Ling Ma

AbstractPrior literature emphasizes the distinct roles of differently affiliated venture capitalists (VCs) in nurturing innovation and entrepreneurship. Although China has become the second largest VC market in the world, the unavailability of high-quality datasets on VC affiliation in China’s market hinders such research efforts. To fill up this important gap, we compiled a new panel dataset of VC affiliation in China’s market from multiple data sources. Specifically, we drew on a list of 6,553 VCs that have invested in China between 2000 and 2016 from CVSource database, collected VC’s shareholder information from public sources, and developed a multi-stage procedure to label each VC as the following types: GVC (public agency-affiliated, state-owned enterprise-affiliated), CVC (corporate VC), IVC (independent VC), BVC (bank-affiliated VC), FVC (financial/non-bank-affiliated VC), UVC (university endowment/spin-out unit), and PenVC (pension-affiliated VC). We also denoted whether a VC has foreign background. This dataset helps researchers conduct more nuanced investigations into the investment behaviors of different VCs and their distinct impacts on innovation and entrepreneurship in China’s context.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3960
Author(s):  
Hong-Ling Hou ◽  
Guang-Peng Zhang ◽  
Chen Xin ◽  
Yong-Qiang Zhao

In the internal thread extrusion forming, if the process parameters are not selected properly, the extrusion torque will increase, the extrusion temperature will be too high, or even the tap will break. In order to obtain effective process parameters under certain working conditions, this paper uses a combination of numerical simulation and process experiment to analyze the influence of the bottom hole diameter, extrusion speed, and friction factor on the extrusion torque and extrusion temperature. Through an orthogonal experiment, the significant influence law of different process parameters on the extrusion torque and extrusion temperature was studied, and the order of their influence was determined. Based on the optimal process parameters, numerical simulations and process tests were carried out, and the extrusion effect and related parameters were compared and analyzed. The results show that the extruded thread has clear contour, uniform tooth pitch, complete tooth shape, and good flatness. Compared with before optimization, the maximum extrusion torque has been reduced by 37.15%, the maximum temperature has been reduced by 29.72%, and the extrusion quality has been improved. It shows that the optimized method and optimized process parameters have good engineering practicability.


2022 ◽  
Vol 41 (1) ◽  
pp. 1-17
Author(s):  
Xin Chen ◽  
Anqi Pang ◽  
Wei Yang ◽  
Peihao Wang ◽  
Lan Xu ◽  
...  

In this article, we present TightCap, a data-driven scheme to capture both the human shape and dressed garments accurately with only a single three-dimensional (3D) human scan, which enables numerous applications such as virtual try-on, biometrics, and body evaluation. To break the severe variations of the human poses and garments, we propose to model the clothing tightness field—the displacements from the garments to the human shape implicitly in the global UV texturing domain. To this end, we utilize an enhanced statistical human template and an effective multi-stage alignment scheme to map the 3D scan into a hybrid 2D geometry image. Based on this 2D representation, we propose a novel framework to predict clothing tightness field via a novel tightness formulation, as well as an effective optimization scheme to further reconstruct multi-layer human shape and garments under various clothing categories and human postures. We further propose a new clothing tightness dataset of human scans with a large variety of clothing styles, poses, and corresponding ground-truth human shapes to stimulate further research. Extensive experiments demonstrate the effectiveness of our TightCap to achieve the high-quality human shape and dressed garments reconstruction, as well as the further applications for clothing segmentation, retargeting, and animation.


2009 ◽  
Vol 6 (1) ◽  
pp. 42-48 ◽  
Author(s):  
R. Perrone ◽  
H. Bartsch de Torres ◽  
M. Hoffmann ◽  
M. Mach ◽  
J. Müller

Embedded ceramic coils stand out because of their excellent dielectric, thermal, and RF properties. However the relatively high sheet resistance (low thickness) of printed thick-film conductors restricts their functionality for applications where current values of several amps are needed. Using embossed structures it is possible to manufacture conductors with increased thickness and low resistance on LTCC tapes. The manufacturing process for wide conductors with high dimensional accuracy was shown in previous publications. In this work fine line embossed structures with line widths and spaces of 50 and 75 μm respectively were realized. The cross section of the embossed channels was about 50 μm. The fine line screen printing, stencil printing, and the photo definable Fodel® processes were used to fill the small structures with thick-film ink. The whole process was used to manufacture several types of low resistance coils in LTCC that can be used for current values up to approximately 3 A. They were realized as embedded as well as SMD components. Thus, the functionality of LTCC modules and LTCC SMD coils was increased. In this paper, the filling and patterning characteristics of all structuring methods are compared and the results discussed. Furthermore, the advantages of this process are shown by electrical, thermal, and RF measurements.


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