Precision Forming of the Straight Edge of Square Section by Die-Less Spinning

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Z. Jia ◽  
Q. Xu ◽  
Z. R. Han ◽  
W. F. Peng
Keyword(s):  
Experimental Result ◽  
Forming Process ◽  
Second Amendment ◽  
Forming Accuracy ◽  
Roller Path ◽  
Development Cycle ◽  
Short Development Cycle ◽  
Spinning Process ◽  
Low Costs ◽  
Geometric Relationship

Die-less spinning is a forming process to achieve cone shape parts. It is suitable for small batch production because of low costs and short development cycle. In order to increase the forming accuracy of the square section die-less spinning process, the roller path is designed and amended. Using a 5-axis CNC spinning machine, the square section cone is spun and its edge arc degree is calculated. Roller path amendment coefficient is proposed and deduced through the geometric relationship. Based on the experimental result in which the amendment coefficient is employed, the second amendment coefficient is deduced and used to perform another spinning experiment. By comparison of the section edge arc degrees of the workpiece obtained with and without using the amendment coefficients, it is found that the forming accuracy in experiments with the amendment is remarkably enhanced.

scholarly journals Study on strong spinning preparation method and mechanism of the industrial pure titanium ultrafine crystallization

2019 ◽  
Vol 14 ◽  
pp. 155892501989525
Author(s):  
Yu Yang ◽  
Yanyan Jia
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
Pure Titanium ◽  
Grain Structure ◽  
Theoretical Research ◽  
Ultrafine Grain ◽  
Forming Process ◽  
Spinning Process ◽  
And Performance ◽  
Material Utilization

Ultrafine crystallization of industrial pure titanium allowed for higher tensile strength, corrosion resistance, and thermal stability and is therefore widely used in medical instrumentation, aerospace, and passenger vehicle manufacturing. However, the ultrafine crystallizing batch preparation of tubular industrial pure titanium is limited by the development of the spinning process and has remained at the theoretical research stage. In this article, the tubular TA2 industrial pure titanium was taken as the research object, and the ultrafine crystal forming process based on “5-pass strong spin-heat treatment-3 pass-spreading-heat treatment” was proposed. Based on the spinning process test, the ultimate thinning rate of the method is explored and the evolution of the surface microstructure was analyzed by metallographic microscope. The research suggests that the multi-pass, medium–small, and thinning amount of spinning causes the grain structure to be elongated in the axial and tangential directions, and then refined, and the axial fiber uniformity is improved. The research results have certain scientific significance for reducing the consumption of high-performance metals improving material utilization and performance, which also promote the development of ultrafine-grain metals’ preparation technology.

Affected Characteristics Analysis of the Pulsed Laser Forming of Metal Sheet

2008 ◽  
Vol 375-376 ◽  
pp. 333-337
Author(s):  
Li Jun Yang ◽  
Yang Wang
Keyword(s):  
Laser Beam ◽  
Pulsed Laser ◽  
Metal Sheet ◽  
Grain Structure ◽  
Experimental Result ◽  
Laser Forming ◽  
Forming Process ◽  
Grain Orientations ◽  
Characteristics Analysis ◽  
Relationship Of

Laser forming of metal sheet is a forming technology of sheet without a die that the sheet is deformed by internal thermal stress induced by partially irradiation of a laser beam. In this paper, the bending behavior of common stainless steel 1Cr18Ni9 sheet is studied after being irradiated by straight line with a Nd:YAG pulsed laser beam. The aim of the investigation is to find out the relationship of the physical behaviors of heat affected zone (HAZ) with the pulse parameters of the laser. Through the analysis of the fundamental theory of pulsed laser affected, this paper shows the affected characteristics of metal sheet with pulsed laser forming. The results show that the microstructure of HAZ of pulsed laser scanned is layered, and the micro-hardness is improved than that in matrix. The microstructures show that the deformed grain structure is inhomogeneous, that caused the grain sizes and grain orientations in HAZ to become different. By qualitative analysis of experimental result, the conclusion obtained may provide basis for theoretical investigation and possible industrial application of laser forming process in the future.

Principle and Simulation Study on Multi Point-Single Point Incremental Combined Forming for Sheet Metal

2009 ◽  
Vol 626-627 ◽  
pp. 273-278 ◽  
Author(s):  
X.J. Li ◽  
Ming Zhe Li ◽  
C.G. Liu ◽  
Zhong Yr Cai
Keyword(s):  
Sheet Metal ◽  
Single Point ◽  
Experimental Result ◽  
Work Piece ◽  
The Novel ◽  
Forming Process ◽  
Explicit Finite Element ◽  
Forming Defect ◽  
Forming Technology ◽  
Elastic Cushion

Based on Multi-Point (MP) forming technology and Single-Point Incremental (SPI) forming technology, MP-SPI combined forming method for sheet metal is proposed, the principle and two different forming techniques are illustrated firstly. Then the paper is focused on numerical analysis for the novel forming technique with explicit Finite Element (FE) algorithm. During simulation of spherical work-piece, dimpling occurs as a main forming defect in MP-SPI combined forming process. Simulation results show that the dimpling defect can be suppressed effectively by using elastic cushion. An appropriate thickness of elastic cushion is necessary to prevent dimpling. And also the deformation of the work-piece is sensitive to the shape of elastic cushion. The combined forming test shows that the numerical simulation result is closed to the experimental result.

Effect of High Pressure Carbon Dioxide Fluids on the Birefringence of Polymer Optical Fiber

2011 ◽  
Vol 148-149 ◽  
pp. 1299-1302
Author(s):  
Chuan Zhao ◽  
Jang Ping He ◽  
Jan Wei Xing ◽  
Hisada Kenji ◽  
Teruo Hori
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Optical Fiber ◽  
Experimental Result ◽  
Polymer Optical Fiber ◽  
Forming Process

In this paper we report a method for reduce the birefingence of polymer optical fiber by using high pressure carbon dioxide fluids. Polymer optical fiber, in the manufacturing and forming process, it is effected by the external drawing and cooling so that the optical fiber presents exhibit birefringence. The experimental result shows that after the treatments of carbon dioxide fluids, the birefringence of optical fiber drop from 2-2.1×10- 4to 4.1-4.6×10- 5.

Design of Digital Pulse Compression System Based on FPGA

2014 ◽  
Vol 1049-1050 ◽  
pp. 1718-1721
Author(s):  
Yan Xin Yu ◽  
Chun Yang Wang ◽  
Yu Chen ◽  
Ke Yang
Keyword(s):  
Pulse Compression ◽  
Radar Signal ◽  
Real Time Processing ◽  
Compression System ◽  
Development Cycle ◽  
Short Development Cycle ◽  
Digital Pulse ◽  
Fast Processing ◽  
Linear Frequency Modulated Signal ◽  
High Degree

Pulse compression technology is one of the key technologies in the field of modern radar signal processing, can effectively solve the contradiction between action distance and resolution. In this paper, a radar digital pulse compression system is designed and implemented based on FPGA with linear frequency modulated signal. The digital pulse compression module is designed using FFT IP core which can be reused in different periods of DPC, respectively performing FFT and IFFT calculation, so that the hardware consumption is saved significantly. Therefore, compared with other systems, the system designed in this paper has the characters of fast processing speed, high degree of modularity, real-time processing and short development cycle.

Comparison of the Geometric Accuracy by DSIF Toolpath with SPIF Toolpath

2014 ◽  
Vol 494-495 ◽  
pp. 497-501 ◽  
Author(s):  
Jin Han Wu ◽  
Qiu Cheng Wang
Keyword(s):  
Incremental Forming ◽  
Single Point ◽  
Metal Sheet ◽  
Single Point Incremental Forming ◽  
Geometric Accuracy ◽  
Forming Process ◽  
Forming Accuracy ◽  
Finite Method

As there is no sufficient support between the single moving tool and fixture, the formed metal sheet is easy to bend in single point incremental forming (SPIF). Double sided incremental forming (DSIF) is proposed in which two tools are used on each side of the sheet to improve the components forming accuracy. Element finite method is introduced to simulate the forming process with both DSIF and SPIF toolpaths and the component geometric accuracies are compared. The simulation result shows the DSIF toolpaths can obtain better geometric accuracy than SPIF.

Design and Simulation of Signal Generator Based on FPGA

2014 ◽  
Vol 608-609 ◽  
pp. 949-953
Author(s):  
Qiang Chen
Keyword(s):  
Frequency Synthesizer ◽  
Low Cost ◽  
Basic Structure ◽  
Frequency Synthesis ◽  
Function Generator ◽  
Current Function ◽  
Digital Frequency ◽  
Development Cycle ◽  
Short Development Cycle ◽  
Direct Digital Frequency Synthesizer

The article introduced the basic structure and the realization principle of direct digital frequency synthesizer (DDS), and analyzed main properties of DDS system, compared the different ways to achieve frequency synthesis to determine the design scheme in this paper. In addition to the realization of general waveform, the output of the system can realize any hand-painted waveform, improve the shortcomings of the current function generator, and also has the advantages of low cost, low power consumption, short development cycle, flexible design, has the very good practical value and broad application prospect.

Research on a Compiler for NC System Based on PC

2011 ◽  
Vol 189-193 ◽  
pp. 2875-2878
Author(s):  
Hai Lang Liu ◽  
Cheng De Lin ◽  
Ai Zhen Wang
Keyword(s):  
High Efficiency ◽  
Rapid Development ◽  
Engineering Application ◽  
Numerical Control ◽  
Syntax Analysis ◽  
Nc System ◽  
Nc Code ◽  
Development Cycle ◽  
Short Development Cycle ◽  
Computer Numerical Control System

With the constant development of numerical control technology, the development cycle and efficiency of CNC (computer numerical control) system is restricted with NC code compiler insufficient in Rapid Development and efficiency. In order to solve this problem, a compiler developed with Lex&Yacc for CNC system based on PC is put forward. This compiler is consisted of a lexical analysis module, a syntax analysis module and an object-storage module. With designed in modules, parameter-driven programming and assisted by Lex&Yacc which is an efficient language for compiler development, this compiler has great advantages such as high efficiency and short development cycle, which mean realistic significance to engineering application. The main principal and design process of every module was expatiated and at last a test of compiling a NC file was executed successfully, which verified the validity of this proposed method.

Numerical simulation of the airflow field in vortex spinning processing

2018 ◽  
Vol 89 (6) ◽  
pp. 1113-1127 ◽  
Author(s):  
Shanshan Shang ◽  
Jianping Yang ◽  
Chongwen Yu
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Stable Process ◽  
Three Dimensional ◽  
Experimental Result ◽  
Initial State ◽  
Suction Force ◽  
Spinning Process ◽  
Airflow Field ◽  
Yarn Tenacity

Three-dimensional numerical simulation of the airflow characteristics during the whole vortex spinning process, including the initial state of the yarn drawing-in process and the normal stable process, were obtained and analyzed. Spinning experiments, with the aid of a scanning electron microscope, were adopted to verify the results of the numerical simulation. The numerical simulation results show that the turbulence phenomenon in the normal spinning process is much more obvious than that in the initial spinning process; the air streamlines move orderly in the initial spinning process, which will produce a strong suction force that will be conducive to drawing the fiber bundle into the nozzle successfully, but the trajectory of airflow is complex in the normal stable spinning process and there is an upstream airflow with the same direction as the rotating airflow to provide extra tension for the yarn, which can improve the strength of the resultant yarn. The spinning experimental result is consistent with the result predicted by numerical simulation. The research further reveals the flow regularity and the turbulent phenomenon of the high-speed rotating airflow, predicts the effect of airflow motion on the spinning effect, and is helpful for stabilizing the spinning process and improving the yarn tenacity.

Simulation of Electric Upsetting and Forging Process for Large Marine Diesel Engine Exhaust Valves

2006 ◽  
Vol 510-511 ◽  
pp. 142-145 ◽  
Author(s):  
H.S. Jeong ◽  
J.R. Cho ◽  
Nak Kyu Lee ◽  
H.C. Park
Keyword(s):  
Diesel Engines ◽  
Manufacturing Process ◽  
Process Condition ◽  
Exhaust Valve ◽  
Experimental Result ◽  
Optimum Process ◽  
Forming Process ◽  
Marine Diesel ◽  
Electric Upsetting ◽  
Exhaust Valves

The manufacturing process of the exhaust valve in large marine diesel engines consists of an upset forging and final forming process. In the past, the exhaust valves in large marine diesel engines have been made through free forging by using the stretch forming method. This method has used the ingot and the billet as a preliminary forming process. Nimonic 80A, a superalloy, is presently used for the material of the exhaust valve. For the forming method of the valve, the electric upset method is used. Solid bar is raised up to the forming temperature by using electric energy and is continually deformed by upset pressure. The electric upsetting processing is a useful method for the high quality of exhaust valves in large marine diesel engines. It can keep the continuous grain flow, excellent mechanical property, and corrosion resistance because of the elaborate macrostructure of the valve face. The purpose of this paper is to predict the optimum process condition through simulation of the exhaust valve with a diameter of 73mm. The experimental result of an exhaust valve with a diameter of 19mm is in good agreement with the simulation result using the “QForm” that can solve electric upsetting problems. Finally, the optimal manufacturing process of the electric current and the upset load are surveyed.

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