Study on Square Conical Box NC Sheet Meta Incremental Forming

2011 ◽  
Vol 308-310 ◽  
pp. 1012-1015
Author(s):  
Liu Ru Zhou

The principle of NC incremental sheet metal forming as well as the process planning, experiment of the square conical box forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to stretch deformation and thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. The sine law indicates that the thickness of the square conical box wall is close to zero when the half-apex angle of the square conical box wall is close to zero. Therefore, we must know the forming limit half-apex angle to ensure that the forming can be carried out successfully, i.e., to ensure that the deformed region with a certain thickness will not fracture. It will succeed in square conical box incremental forming in a single tool-path if the forming is carried out with an angle which is larger than the forming limit half-apex angle. The fracture in the forming component can be avoided by these methods. A square conical box of uniform wall-thickness can be formed by NC incremental forming process. The thickness of deformation area is increased by increasing half-apex angle. The wrinkle in the forming component can be avoided by these methods.

2011 ◽  
Vol 308-310 ◽  
pp. 1004-1007
Author(s):  
Liu Ru Zhou ◽  
Hai Ming Wan

The principle of NC incremental sheet metal forming as well as the process planning, experiment of the square conical box forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to stretch deformation and thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. The sine law indicates that the thickness of the square conical box wall is close to zero when the half-apex angle of the square conical box wall is close to zero. Therefore, we must know the forming limit half-apex angle to ensure that the forming can be carried out successfully, i.e., to ensure that the deformed region with a certain thickness will not fracture. It will succeed in square conical box incremental forming in a single tool-path if the forming is carried out with an angle which is larger than the forming limit half-apex angle. The fracture in the forming component can be avoided by these methods. A square conical box of uniform wall-thickness can be formed by NC incremental forming process. The thickness of deformation area is increased by increasing half-apex angle. The wrinkle in the forming component can be avoided by these methods.


2011 ◽  
Vol 239-242 ◽  
pp. 1036-1039
Author(s):  
Liu Ru Zhou

The principle of NC incremental sheet metal forming as well as the process planning, experiment of sphere forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to shear deformation and thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. According to sine law, a sphere can’t be formed by NC incremental sheet metal forming process in a single process, rather, it must be formed in multi processes. Thus, the two time path process method is presented to form the sphere, and the experiment is made to verify it. A sphere can be formed from a sheet metal in NC incremental forming process by choosing appropriate tool-path planning. The fracture in the forming component can be avoided by these methods. A sphere of uniform wall-thickness can be formed from the truncated cone by NC incremental forming process.


Author(s):  
Rakesh Lingam ◽  
Anirban Bhattacharya ◽  
Javed Asghar ◽  
N. Venkata Reddy

Incremental Sheet Metal Forming (ISMF) is a flexible sheet metal forming process that enables forming of complex three dimensional components by successive local deformations without using component specific tooling. ISMF is also regarded as die-less manufacturing process and in the absence of part-specific dies, geometric accuracy of formed components is inferior to that of their conventional counterparts. In Single Point Incremental Forming (SPIF), the simplest variant of ISMF, bending near component opening region is unavoidable due to lack of support. The bending in the component opening region can be reduced to a larger extent by another variant of ISMF namely Double Sided Incremental Forming (DSIF) in which a moving tool is used to support the sheet locally at the deformation zone. However the overall geometry of formed components still has unacceptable deviation from the desired geometry. Experimental observation and literature indicates that the supporting tool loses contact with the sheet after forming certain depth. Present work demonstrates a methodology to enhance geometric accuracy of formed components by compensating for tool and sheet deflection due to forming forces. Forming forces necessary to predict compensations are obtained using force equilibrium method along with thickness calculation methodology developed using overlap that occurs during forming (instead of using sine law). Results indicate that there is significant improvement in accuracy of the components produced using compensated tool paths.


2010 ◽  
Vol 139-141 ◽  
pp. 1514-1517 ◽  
Author(s):  
Liu Ru Zhou

The incremental sheet metal forming technology is a flexible forming technology without dedicated forming dies. The locus of the forming tool can be adjusted by correcting the numerical model of the product. The effect of forming half-apex angle on forming process with all kind of sheet material, sheet thickness and ironing ratio is researched. The limit half-apex angle is different for all kind of sheet material and thickness. The limit half-apex angle is smaller for the larger thickness of sheet metal. It will succeed in square conical box incremental forming in a single tool-path if the forming is carried out with an angle which is larger than the forming limit half-apex angle θ. The ironing ratio ψt is decided by the forming half-apex angle θ. The ironing ratio ψt varies with θ. The ironing ratio ψt is smaller when is larger.


Author(s):  
Chetan P. Nikhare

Abstract A substantial increase in demand on the sheet metal part usage in aerospace and automotive industries is due to the increase in the sale of these products to ease the transportation. However, due to the increase in fuel prices and further environmental regulation had left no choice but to manufacture more fuel efficient and inexpensive vehicles. These heavy demands force researchers to think outside the box. Many innovative research projects came to replace the conventional sheet metal forming of which single point incremental forming is one of them. SPIF is the emerging die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any processing time to undergo plastic deformation. It has several advantages over the conventional process like high process flexibility, elimination of die, complex shape and better formability. Previous literature provides enormous research on formability of metal during this process, process with various metals and hybrid metals, the influence of various process parameter, but residual formability after this process is untouched. Thus, the aim of this paper is to investigate the residual formability of the formed parts using single point incremental forming and then restrike with a conventional tool. The common process parameters of single point incremental forming were varied, and residual formability was studied through the conventional process. The strain and thickness distribution were measured and analyzed. In addition, the forming limit of the part was plotted and compared.


2011 ◽  
Vol 473 ◽  
pp. 889-896 ◽  
Author(s):  
D. Kreimeier ◽  
J. Zhu ◽  
V. Smukala ◽  
B. Buff ◽  
C. Magnus

Robot based incremental sheet metal forming (Roboforming)is a new dieless forming process, which is suitable for cost-effective manufacture of prototype parts and small batch sizes.The principle of Roboforming is based on flexible shaping through a freely programmable path-synchronous movement of two industrial robots. These two robots, which are connected to a cooperating robot system, hold respectively a forming and a supporting tool. Similar to other incremental forming methods, the final shape is produced bythe movement of the forming toolalongthe lateral direction and its gradual infeed in the depth direction. In Roboforming, there are twodifferent strategies for the synchronous movement of the supporting tool, eitheralong the outer contour onbacksideof the sheet or directly opposed to the forming tool building a forming gap.The second strategy can be combined with a force controlled method to increase the surface quality and geometricaccuracy. MThe most existing CAM systems used in numerous incremental forming approaches are only applicable for milling machines. In this paper, with the use of self-programmed postprocessors and an Application Programming Interface (API) in a CAM system, movement programs for two cooperating robots can be generated for both forming strategies to produce sheet metal parts with different sizes and complex freeform structures. This CAM-solution for Roboforming is validated bythe forming experiments.


2009 ◽  
Vol 410-411 ◽  
pp. 159-166 ◽  
Author(s):  
Horst Meier ◽  
B. Buff ◽  
V. Smukala

This paper describes new developments in incremental, robot-based sheet metal forming (Roboforming). Roboforming is a dieless sheet metal forming process which ensures cost-effective manufacturing of prototype parts and small batches. An approach for increasing the part accuracy in Roboforming is presented. It is developed in a cooperative project funded by the German Federal Ministry of Education and Research called Roboforming. The project concentrates on the development of an industrial applicable system design. The use of standard components allows a modular and scalable set-up. A servo loop, consisting of sensors and a programming system, represents the basis of this design and shall guarantee higher part accuracies by measuring the deviations between a formed part and its target geometry. The deviations are used to derive corrected tool paths. The correction is performed by an adjustment vector for every point on the tool path. The theory for this strategy and first results are presented in this paper.


Author(s):  
Ramkumar Kathalingam ◽  
Baskar Neelakandan ◽  
Elangovan Krishnan ◽  
Sathiya Narayanan Chinnayan ◽  
Selvarajan Arangulavan ◽  
...  

Incremental Sheet metal Forming (ISF) is a reliable process of converting a blank to work piece with better outputs compared to conventional forming process. The flexibility of ISF in producing the rapid prototype based on the customer needs is increased which is also desirable in the industry. But Single Point Incremental Forming (SPIF) process takes more time to form a product and hence the longer time is a barrier in implementing this process in industries. In this research work, the ISF process was made on sheet metal SS 202 using a newly designed multi-point tool and the obtained outputs were compared with the same material of sheet metal formed by traditionally available single point tool. This Multi Point Incremental Forming (MPIF) process takes lesser process time to give better formability, improved wall angle and good surface roughness. The input process parameters selected for the process are type of tool, speed, feed, Vertical Step Depth (VSD), and lubrication. They are arranged by using the taguchi Design of Experiments (DOE) approach. The responses considered are wall angle, formability, surface roughness, spring back and forming time. The multiple outputs obtained were optimized by Grey Relational Analysis (GRA) to predict the superior parameter. Confirmation test was also made to validate the output result. Fractography analysis was carried out to predict the fracture mechanism obtained during the forming process. The surface topography was also made on the surface of the formed area of the sheet metal. This research work concludes that newly designed MPIF outperforms SPIF.


2011 ◽  
Vol 239-242 ◽  
pp. 940-943 ◽  
Author(s):  
Liu Ru Zhou

The principle of NC incremental sheet metal forming process as well as the experiment of cone forming are presented. Because the deformation of sheet metal only occurs around the tool head and the deformed region is subjected to stretch deformation, the deformed region of sheet metal thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheet metal deformation. The experiment results show that in the case of the parallel line type tool path, a uniform thickness of the deformed region is maintained and in good accordance with that obtained by the sine law. It is found that success in the forming depends on the forming half-apex angleθof the truncated cone. It can be obtained that NC incremental sheet metal forming process is a plane deform process and conforms to the sine law, i.e.t=t0 sinQ.


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