scholarly journals The Influence of the Bottom Hole of Cold Extruding Internal Thread on Thread Quality

Mechanika ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 335-341
Author(s):  
Hongling Hou ◽  
Xin CHEN ◽  
Yongqiang ZHAO ◽  
Yayin HE ◽  
Changqian WANG
Keyword(s):  
Numerical Simulation ◽  
Extrusion Process ◽  
High Rate ◽  
Cold Extrusion ◽  
Internal Thread ◽  
Important Indicator ◽  
Good Surface ◽  
Bottom Hole ◽  
Simulation Results ◽  
The Relationship

The diameter of the threaded bottom hole determines whether the extrusion can proceed smoothly and the fullness of the tooth shape after extrusion. The tooth height rate is an important indicator of the strength of the threaded connection. In order to establish the relationship between the diameter of the bottom hole and the tooth height of the extruded internal thread, this paper takes the aluminum alloy M8×1.25 mm internal thread as an example, and uses a method of combining numerical simulation and process test. Obtained the changing law of internal thread profile and tooth height rate of extruded workpieces with different bottom hole diameters. Using MATLAB to fit the numerical simulation results, the relationship between the tooth height of the internal thread and the diameter of the prefabricated bottom hole of the workpiece was obtained. The reliability of the numerical simulation results and the feasibility of the fitting formula are verified through experiments. The results show that the diameter of the prefabricated bottom hole of the workpiece is controlled within 7.33~7.39 mm when the M8×1.25 mm internal thread is processed by the cold extrusion process. The high rate of the internal thread after extrusion meets the requirements of thread connection strength, and the internal thread has high forming quality and good surface quality.

scholarly journals Numerical Simulation and Process Optimization of Internal Thread Cold Extrusion Process

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3960
Author(s):  
Hong-Ling Hou ◽  
Guang-Peng Zhang ◽  
Chen Xin ◽  
Yong-Qiang Zhao
Keyword(s):  
Numerical Simulation ◽  
Process Parameters ◽  
Orthogonal Experiment ◽  
Extrusion Process ◽  
Extrusion Temperature ◽  
Maximum Temperature ◽  
Cold Extrusion ◽  
Internal Thread ◽  
Bottom Hole ◽  
Extrusion Forming

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.

Research on the Relationship of Flow Velocity and Particles’ Separation in Cyclone

2012 ◽  
Vol 479-481 ◽  
pp. 2529-2532
Author(s):  
Ying Zhang ◽  
Zhen Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Flow Velocity ◽  
Structure Design ◽  
Rotating Flow ◽  
Separation Performance ◽  
Simulation Results ◽  
Relationship Of ◽  
The Relationship ◽  
Distribution Of Flow

This paper mainly focuses on the numerical simulation of flow velocity aiming to obtain the velocity distribution of flow in the cyclone. The authors took advantage of RSM turbulence model of software FLUENT to calculate the velocity distribution. Relationship between particles separation and double-layer rotating flow can be obtained based on the simulation results, which can also provide basis for the improvement of structure design and separation performance.

scholarly journals Numerical Simulation of Borehole Parameters for Coal Seam Gas Pre-Drainage

2021 ◽  
Vol 39 (4) ◽  
pp. 1328-1334
Author(s):  
Xiaoyan Li ◽  
Jiyu Zheng ◽  
Jinpin Liu
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Gas Pressure ◽  
Borehole Diameter ◽  
Gas Drainage ◽  
Drainage Time ◽  
Drainage Radius ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

Borehole parameters are quite important for gas drainage. This paper studies the impact of borehole diameter and time on gas drainage and performs numerical simulation on the distribution of gas pressure under the conditions of different borehole diameters and drainage times. The simulation results reveal that, as the borehole diameter increases, the gas drainage volume increases along with it and the gas pressure decreases, but such effect on gas drainage is limited. In terms of drainage time, the longer the drainage time, the greater the drainage impact scope. Taking a gas pressure drop of 51% as the indicator of the effective pre-drainage radius, the distance from the point with a gas pressure drop of 51% to the position of the borehole is the effective pre-drainage radius. When the pre-drainage reached the 30th, 45th, 60th, 75th, and 90th day, the effective pre-drainage radius was 1.04m, 1.29m, 1.51m, 1.68m, and 1.82m respectively. According to the numerical simulation results, the effective pre-drainage radius varies with the pre-drainage time, and the fitting analysis of the two indicates that the relationship between the two can be described by a power function.

Simulation and Experimental Study on the Impact of Breadth of Back Blade on Axial Force Balance

2011 ◽  
Vol 130-134 ◽  
pp. 1568-1572
Author(s):  
Hui Wang ◽  
Jie Gang Mu ◽  
Miao Yin Su ◽  
Shui Hua Zheng ◽  
Jin Jing Zhao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Axial Force ◽  
Three Dimensional ◽  
Force Balance ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

The paper studies the relationship between axial force and breadth of back blade by numerical simulation and experiment. On the basis of the RNG k-ε turbulence model and technology of compact local grids and regional computing, three dimensional numerical simulations to 100HZ165-250 centrifugal pump with various breadths were carried out. Through comparing and analyzing of the flow field, it can be seen that the axial force reduces with the increase of the back blade breadth. After that, the simulation results were verified by the experimental data got from different test devices, and it shows that the conclusions are reliable.

Research on the Decision Support System for Cold Extrusion Process of Internal Thread

2016 ◽  
Vol 693 ◽  
pp. 1867-1879
Author(s):  
Hong Miao ◽  
Qing Mei ◽  
Jing Yun Yuan ◽  
Zai Xiang Zheng ◽  
Yi Fu Jin ◽  
...  
Keyword(s):  
Decision Support ◽  
Decision Support System ◽  
Support System ◽  
Three Dimensional ◽  
Extrusion Process ◽  
Frame Structure ◽  
Cold Extrusion ◽  
Internal Thread ◽  
Related Information ◽  
Application Requirements

This paper established the model base, knowledge base, application base and test base for the cold extrusion process of internal thread and developed decision support system which realized the centralized management of related information for cold extrusion process of internal thread, maintained the consistency of data in real time and enforced the degree of information sharing. By using of the decision support system, expert system, intelligent inference technology and depending on the application requirements of the system, the overall structure of the decision support system for cold extrusion process of internal thread was established based on J2EE technology. Two accessorial decision-making methods of hybrid forecasting and application modification facilitated modeling the system business. Three-dimensional frame structure was used to represent the application example of the internal thread by cold extrusion process and to achieve the application type, information scalability of internal thread by cold extrusion process. Hybrid fast predicting mechanism which was the dynamic integration of internal thread by cold extrusion process knowledge and instance inference was applied to seek the optimal degree of internal thread by cold extrusion process.

Numerical Simulation of the Extrusion Process with Feeder Plate Die

2014 ◽  
Vol 926-930 ◽  
pp. 3521-3526
Author(s):  
Tian Xiao Chen ◽  
Chun Mei Li ◽  
Nan Pu Cheng ◽  
Hui Na Jia
Keyword(s):  
Numerical Simulation ◽  
Material Flow ◽  
Strain Distribution ◽  
Extrusion Process ◽  
Geometric Parameters ◽  
Geometrical Parameters ◽  
Direct Extrusion ◽  
Axial Hole ◽  
Hole Defect ◽  
Simulation Results

The direct extrusion process by using a newly designed die with different angle and feeder plate numbers has been simulated to systematically investigate the effects of different geometric parameters angle and feeder plate number on the strain distribution, the load and the axial hole defect. The simulation results show that the extrusion process with multiple feeder plate die is similar to that of the extrusion for many times. The angle and feeder plate make the material flow more fluently and ameliorate the axial hole defect. The larger angle reduces the load while the feeder plate increases it. Suitable geometrical parameters can significantly enhance strain in workpiece.

Finite element analysis of piping defect formation in the sheet-extrusion process

2015 ◽  
Vol 06 (01) ◽  
pp. 1550010
Author(s):  
Wiriyakorn Phanitwong ◽  
Sutasn Thipprakmas
Keyword(s):  
Finite Element ◽  
Defect Formation ◽  
Fem Simulation ◽  
Extrusion Process ◽  
Machining Process ◽  
Work Piece ◽  
Element Analysis ◽  
Simulation Results ◽  
Sheet Extrusion ◽  
The Relationship

The pressing process, as compared to the machining process, makes good utilization of work piece material and shortens the production time, and as such it is increasingly used for production of complex shaped parts. A particular type of pressing is sheet-extrusion which controls the flow of material into special punch and die sets to produce an extruded shape. However, some particularly complex shaped parts cannot be made by sheet-extrusion due to the formation of piping defects. In this study, the finite element method (FEM) was used to investigate the formation of piping defects. In addition, the relationship between the characteristic dimensions of the extruded shape and the piping defect was also examined. Laboratory pressing experiments were performed to validate the accuracy of the FEM simulation results. Based on the stress distribution and velocity profiles within the extruded work piece, the relationship between the extruded shape and the piping defect was clearly identified. Furthermore, the FEM simulation results showed good agreement with the experimental results with regards to the dimensions of the extruded shape and the piping defect.

Finite Volume Simulation in Porthole Dies Extrusion of Aluminum Profiles

2011 ◽  
Vol 291-294 ◽  
pp. 290-296
Author(s):  
Lei Cheng ◽  
Shui Sheng Xie ◽  
You Feng He ◽  
Guo Jie Huang ◽  
Yao Fu
Keyword(s):  
Numerical Simulation ◽  
Finite Volume ◽  
Cross Section ◽  
Process Analysis ◽  
Flow Behavior ◽  
Metal Flow ◽  
Extrusion Process ◽  
Porthole Die ◽  
Simulation Results ◽  
Aluminum Profiles

FEM simulation of aluminum profiles in porthole die extrusion process using Lagrange mesh description will inevitably bring mesh self-contact, severe grid distortion and frequent remeshing, which will result in the loss of computational accuracy and excessive calculation time. In order to solve the above mentioned problems, numerical simulation of aluminum profiles with large and complicated cross-section in extrusion process was achieved using finite volume method based on Euler mesh description. The metal flow behavior and welding course was investigated in detail, which can provide the theoretical guide for porthole die design and optimization. In addition, extrusion experiment was carried out by numerical simulation results. The experimental extrudate was in good agreement with the simulation results, which laid a good solid foundation for non-steady state extrusion process analysis of large scale and complicated cross-section profiles.

The Numerical Simulation of Air-Cooled Plate-Fin Heat Exchanger

2011 ◽  
Vol 314-316 ◽  
pp. 1472-1477 ◽  
Author(s):  
Xue Jiang ◽  
Ji Hua Bao ◽  
Yan Yu ◽  
Ming Xia Gu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
3D Model ◽  
Fluid Velocity ◽  
Heat Transfer Characteristics ◽  
Flow And Heat Transfer ◽  
Simulation Results ◽  
Relationship Of ◽  
The Relationship

According to the periodic structure of the plate-fin heat exchanger, 3D model of the heat exchanger is established which simplifies the computation amount of the numerical simulation on flow field and temperature field. The relationship of fluid velocity, temperature, pressure drop and heat transfer coefficient is analyzed. The flow and heat transfer characteristics can be well predicted. Based on the simulation results, the conclusion makes reference to the design of plate-fin heat exchanger.

Research on the Size Effect of Specific Cutting Energy Based on Numerical Simulation of Single Grit Scratching

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Tao Zhang ◽  
Feng Jiang ◽  
Lan Yan ◽  
Xipeng Xu
Keyword(s):  
Numerical Simulation ◽  
Size Effect ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Specific Cutting Energy ◽  
Cutting Energy ◽  
Simulation Results ◽  
The Relationship ◽  
Single Grit Scratch

A method of research on the size effect of the specific cutting energy based on the numerical simulation has been proposed. The theoretical model of the research on size effect of specific cutting energy using single grit scratching simulation has been presented. A series of single grit scratch simulations with different scratching depths have been carried out to acquire different material removal rates. Then, the specific cutting energy has been calculated based on the power consumed and the material removal rate. The relationship between the specific cutting energy and the material removal rate has been given which agrees well with that presented by Malkin. The simulation results have been analyzed further to explain the size effect of specific cutting energy.

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