scholarly journals A Review of Progressive and Compound Forming of Bulk Microparts by Using Sheet Metals

2018 ◽  
Vol 190 ◽  
pp. 01001 ◽  
Author(s):  
M.W. Fu ◽  
J.Y. Zheng ◽  
B. Meng
Keyword(s):  
Size Effect ◽  
Sheet Metal ◽  
Material Flow ◽  
Dimensional Accuracy ◽  
Promising Method ◽  
Sheet Metals ◽  
Forming Process ◽  
Geometrical Feature

In the last decade, the concept of progressive microforming has emerged and developed gradually, which is considered as an efficient and promising method to fabricate the micro-scaled part. Micro-cylinder parts, micro-flanged part, and multi-flanged microparts are representative micro bulk parts by the progressive microforming system using sheet metal. In these cases, many efforts focus on the forming process, such as microblanking and microextrusion. Meanwhile, the quality of the fabricated parts also attracts attention. In this paper, an intensive review on the development of progressive microforming technologies and the formed parts is presented, and the influence of size effect to dimensional accuracy, material flow, geometrical feature, and fracture is also discussed.

Progressive and Compound Forming for Producing Plunger-Typed Microparts by Using Sheet Metal

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Jun-Yuan Zheng ◽  
Ming-Wang Fu
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Sheet Metal ◽  
Mass Production ◽  
Grain Size Effect ◽  
Sheet Metals ◽  
Forming Process ◽  
Deformation Behaviors ◽  
Progressive Forming ◽  
Insight Into

Abstract The plunger part in temporary electronic connectors is traditionally fabricated by micromachining. Progressive forming of microparts by directly using sheet metals is developed and proven to be an efficient microforming process to overcome some intrinsic drawback in realization of mass production of microparts. By employing this unique micromanufacturing process, an efficient approach with progressive microforming is developed to fabricate plunger-shaped microparts. In this endeavor, a progressive forming system for making microplungers using extrusion and blanking operations is developed, and the grain size effect affected deformation behaviors and of surface qualities of the microformed parts are studied. The knowledge for fabrication of plunger-shaped microparts via progressive microforming is developed, and the in-depth understanding and insight into the deformation behaviors and tailoring the product quality and properties will facilitate the design and development of the forming process by using this unique microforming approach.

Asymmetric-Shaped Bending of Adhesively Bonded Sheet Metals

2016 ◽  
Vol 725 ◽  
pp. 630-635 ◽  
Author(s):  
Taro Tokuda ◽  
Takeshi Uemori ◽  
Tetsuya Yoshida ◽  
Michihiro Takiguchi ◽  
Fusahito Yoshida
Keyword(s):  
Sheet Metal ◽  
Final Stage ◽  
Fem Analysis ◽  
Sheet Metals ◽  
Analysis Method ◽  
Adhesively Bonded ◽  
Forming Process ◽  
Maximum Shear Strain ◽  
The Press ◽  
A New Technique

In sheet metal industries, press-formed sheet elements are usually adhesively bonded together at the final stage of assembly. Instead of such a conventional process, the present authors proposed a new technique that first flat sheets are adhesively bonded together and then press-formed into the final products. In previous study, the problem of the die-bending (V-bending and hat-shaped bending) with symmetrical shape has studied. In this study, asymmetric-shaped bending of adhesively bonded sheet metals was investigated by experiments and FEM analysis method. In the case of asymmetric-shaped bending, it was found that the timing of contact from the die corner to the die hypotenuse is early in the press-forming process compared with symmetrical bending (V-bending and hat-shaped bending). For the FEM analysis results, the maximum shear strain in asymmetric-shaped bending was smaller than that in symmetric-shaped bending at the hat-shaped side. Thus, the shape of the die has a large influence on the die-bending of adhesively bonded sheet metals.

The Influnce of Some Parameters on the Quality of Deep Drawing of Cylindrical Cups without a Blank Holder

2015 ◽  
Vol 809-810 ◽  
pp. 259-264
Author(s):  
Dan Chiorescu ◽  
Gheorghe Nagîț ◽  
Oana Dodun
Keyword(s):  
Sheet Metal ◽  
Deep Drawing ◽  
Signal To Noise Ratio ◽  
Fractional Factorial ◽  
Major Influence ◽  
Forming Process ◽  
Sheet Metal Parts ◽  
Product Surface ◽  
Experimental Trials

Deep drawing is one of the most important processes for forming sheet metal parts. Besides its importance as a forming process, cup drawing also serves as a basic test for the sheet metal formability. This article investigates the influence of the die punch clearance, the average velocity in the active stage and the lubrication on the deep drawing quality expressed by the thickness evenness on the finished product surface. In order to minimize the number of experimental trials, a fractional factorial design was developed together with an orthogonal array, thus analyzing the contribution of the three parameters under study to the quality of the deep drawing process. Using TAGUCHI’s signal-to-noise ratio, we determine that ram velocity has a major influence, followed by the clearance between the active elements, while the contribution of lubrication is negligible. The results of the research are useful in developing a sensible design of experiments.

Numerical Simulation of Forming Process for Cover with Stiffening Components Made of Grade 2 Titanium Sheet Metal

2016 ◽  
Vol 687 ◽  
pp. 206-211
Author(s):  
Wojciech Więckowski
Keyword(s):  
Numerical Simulation ◽  
Sheet Metal ◽  
Empirical Studies ◽  
Strength Properties ◽  
Forming Process ◽  
Titanium Sheet ◽  
Plastic Properties ◽  
Fem Method

This study presents the findings of numerical simulations of forming process for an inspection hole cover with stiffening ribs made of thin grade 2 titanium sheet metal. The numerical simulation was carried out using the FEM method with PAMStamp 2G software. Numerical calculations were performed with consideration for the phenomenon of material strain hardening and anisotropy of plastic properties of the sheet metal formed. Properties of the grade 2 titanium alloy analysed in the simulations were adopted based on the results of the empirical studies. Adequate parameters of the forming process were selected in order to eliminate unfavourable phenomena of losing of material coherence and sheet metal wrinkling. The effect of conditions of friction between the sheet metal and tool and pressure force of the blank holder on the forming process was investigated. The analysis of the distribution of plastic strain and reduction in wall thickness of the drawn parts can be used for determination of the effect of changes in selected parameters and orientation of the specimen on the process of drawn part forming. The quality of drawn parts was assessed based on the shape inaccuracy determined during simulation of forming. The inaccuracy depended on the conditions of the process and strength properties of the titanium sheet metal.

Multi-Input Multi-Output (MIMO) Modeling and Control for Stamping

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Yongseob Lim ◽  
Ravinder Venugopal ◽  
A. Galip Ulsoy
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Material Flow ◽  
Process Model ◽  
Complex Geometry ◽  
Flow Characteristics ◽  
Forming Process ◽  
Punch Force ◽  
Force System

The binder force in sheet metal forming controls the material flow into the die cavity. Maintaining precise material flow characteristics is crucial for producing a high-quality stamped part. Process control can be used to adjust the binder force based on tracking of a reference punch force trajectory to improve part quality and consistency. The purpose of this paper is to present a systematic approach to the design and implementation of a suitable multi-input multi-output (MIMO) process controller. An appropriate process model structure for the purpose of controller design for the sheet metal forming process is presented and the parameter estimation for this model is accomplished using system identification methods. This paper is based on original experiments performed with a new variable blank holder force (or variable binder force) system that includes 12 hydraulic actuators to control the binder force. Experimental results from a complex-geometry part show that the MIMO process controller designed through simulation is effective.

Improving the Cut Edge by Counter-Shaving

2007 ◽  
Vol 344 ◽  
pp. 217-224 ◽  
Author(s):  
Hartmut Hoffmann ◽  
Florian Hörmann
Keyword(s):  
Sheet Metal ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Burr Formation ◽  
Cut Edge ◽  
Edge Quality ◽  
Metal Materials ◽  
The Right ◽  
Two Stages

In blanking operations the cut edge of the sheet metal is not clear due to fracturing and burr formation by the shearing process. For precision parts with high quality and dimensional accuracy, often secondary machining is necessary. Shaving, in particular, counter-shaving, is a shearing operation to improve the cut edge quality of a blanked part or punched hole in two stages. This paper introduces a progressive die tool to realize the counter-shaving process on a single acting press. In order to realize the shaving operation in the opposite punching direction, the punch needs to move in counter direction. The burr and fracture zone left on the sheet metal after the first stage will be removed by the counter-shaving operation. By choosing the right process parameter a sharpedge transition is formed, without any rollover, between the upper surface of the sheet metal and the sheared-edge. Different punch geometries as well as the corresponding process parameters were part of the research work in order to improve the cut edge. Experimental and FEM results are presented for two sheet metal materials at three thicknesses.

Research on Catalyst Penetration Process of Patternless Casting Manufacturing Technique

2014 ◽  
Vol 609-610 ◽  
pp. 1515-1520 ◽  
Author(s):  
Wei Dong Yang ◽  
Zhan Qun Shi ◽  
Li Li
Keyword(s):  
Rapid Prototyping ◽  
Surface Quality ◽  
Dimensional Accuracy ◽  
Single Droplet ◽  
Forming Process ◽  
Penetration Process ◽  
Forming Quality ◽  
Main Factors ◽  
Sand Particles

Pattenless Casting Manufacturing (PCM) technique is a kind of Rapid Prototyping based on droplet injection, using discrete nozzle to jet the catalyst. The quality of scanning lines has the most important effect on the sand strength, its surface quality and dimensional accuracy. The penetration and curing rules of the catalyst in the resined-sand particles are the main factors to determine the shape of the scanning lines. In order to study the penetration rules of the catalyst in the resined-sand, the penetration process of a single droplet and scanning lines are analyzed theoretically and verified by experiments. The important parameters of the forming process are determined based on the research and experimental results. It will provide the foundation to improve the forming quality of PCM technique.

Numerical Simulation for the Multi-Point Incremental Forming Process

2015 ◽  
Vol 775 ◽  
pp. 219-223
Author(s):  
Wan Mian Yang ◽  
Yuan Xin Luo ◽  
Zhi Fang Liu ◽  
Ru Xu Du
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Finite Element Model ◽  
Sheet Metal ◽  
Incremental Forming ◽  
Element Model ◽  
Sheet Metals ◽  
Forming Force ◽  
Forming Process ◽  
Thickness Change

Multi-point forming process has been developed to shape the sheet metal with bidirectional curvature. However, the forming force usually climbs too high so that the dimension of the forming machine should be designed to meet it. To solve this problem, the multi-point incremental forming (MPIF) process was proposed in this paper. First, the principle of this new forming process was introduced. Then, the experimental device was designed. Next, the MPIF process was simulated by a finite element model. The forming effects including displacements, thickness, and curvatures were visualized and discussed in detail. It was found that there is no obvious thickness change during the forming process. The advantage of this forming process is that the shape of the sheet metals adaptable and controllable with small forming force.

Investigation on Dimensional Accuracy in Micro Cross Wedge Rolling of Metals

2014 ◽  
Vol 622-623 ◽  
pp. 943-948 ◽  
Author(s):  
Haina N. Lu ◽  
D.B. Wei ◽  
Z.Y. Jiang
Keyword(s):  
Size Effect ◽  
Material Flow ◽  
Pure Copper ◽  
Dimensional Accuracy ◽  
Material Consumption ◽  
Cross Wedge Rolling ◽  
Cross Sectional ◽  
Geometrical Accuracy ◽  
Element Simulation ◽  
Micro Parts

A novel microforming process - Micro Cross Wedge Rolling (MCWR) has been developed. It is a very promising technology in the field of microforming due to its advantages such as high product rate and minimised material consumption. How to control geometrical accuracy of the produced micro parts is one of the major challenges in the development of microforming technology. Geometrical accuracy was still concentrated in term of springback. When the wedge tools loads are removed after forming step, a portion of the deformation recovers, which causes a change in the shape of micro parts. In other word, springback happens, which should be determined and controlled especially in microforming technology. A series of MCWR experiments of pure copper and aluminium have been carried out using the machine designed by authors in this study. Cylindrical workpieces were deformed into stepped shafts with cross-sectional area reductions of 35, 52.73 and 75%. Corresponding finite element simulation has also been conducted in consideration of the size effect on the material flow. The springback was proposed to account for the geometrical error of micro products. The effect of grained heterogeneity on the height of surface asperity after rolling was assessed quantitatively. Keywords: Micro cross wedge rolling, Size effect, Dimensional accuracy, Springback

PVC Sheet Blow Forming Finite Element Simulation and Experimental Study

2011 ◽  
Vol 467-469 ◽  
pp. 1846-1851 ◽  
Author(s):  
Chao Zheng ◽  
Yi Sheng Zhang ◽  
De Qun Li
Keyword(s):  
Finite Element ◽  
Complex Geometry ◽  
Experimental Testing ◽  
Thickness Distribution ◽  
Dimensional Accuracy ◽  
Sheet Forming ◽  
Forming Process ◽  
Plastic Sheet ◽  
Element Simulation

The plastic sheet forming technique is simple and easy to realize, that is why, it is widely used for packaging commodities. Similarly, in In-Mold-Decoration (IMD) molding technology, due to the complex geometry of the membrane and the high requirement of the dimensional accuracy, geometric design and molding technique for the product should be focused on controlling the thickness distribution of shell or membrance plastic products in order to achieve high precision manufacturing. This paper started with analyzing the performance data of the plastic sheet molding material, using nonlinear finite element method and multi-physics coupling method to simulate the plastic sheet forming process, and the result gives the required parameters for product design and quality control. For the thickness deviation, the experimental testing shows that the maximum discrepancy between the simulation and actual result is less than15%. The research proved that computer simulation can contribute to control the inhomogeneity of the shell or membrane so as to improve the design and the quality of manufacturing.

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