Two Point Incremental Forming with Two Moving Forming Tools

2007 ◽  
Vol 344 ◽  
pp. 599-605 ◽  
Author(s):  
Horst Meier ◽  
V. Smukala ◽  
O. Dewald ◽  
Jian Zhang
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Industrial Robots ◽  
Forming Process ◽  
Robot System ◽  
Outer Contour ◽  
Lateral Direction ◽  
Depth Direction ◽  
Incremental Sheet Metal Forming

This paper describes a new development of an incremental, robot based sheet metal forming process for the production of sheet metal components for limited-lot productions and prototypes. The kinematic based generation of the shape is implemented by means of two industrial robots, which are interconnected to a cooperating robot system. Compared to other incremental sheet metal forming machines this system offers a high geometrical form flexibility without the need of any workpiece dependent tools. The principle of the procedure is based on flexible shaping by means of a freely programmable path-synchronous movement of two robots. So far, the final shape is produced by the incremental infeed of the forming tool in depth direction and its movement along the contour in lateral direction on each level. The counter tool, with its simple geometry, was used to support the sheet metal on the backside by moving synchronously along the outer contour, constantly on the same level. This corresponds to a fixed backplate used in other incremental sheet metal forming processes. Due to the use of a new robot system with extended control algorithms for cooperating robots, it will be possible to release the counter tool from its constant path on the outer contour and support the forming tool right on the opposite side of the sheet to generate a predefined gap between the two hemispherical tools. This way at each moment a small part of a full die, as it is used in other processes, is simulated without the need of producing a workpiece dependent die. The extended payload of the new robot system gives the opportunity to form steel blanks, for the first time.

CAM-Solution for Two Robots Based Incremental Sheet Metal Forming

2011 ◽  
Vol 473 ◽  
pp. 889-896 ◽  
Author(s):  
D. Kreimeier ◽  
J. Zhu ◽  
V. Smukala ◽  
B. Buff ◽  
C. Magnus
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Incremental Forming ◽  
Industrial Robots ◽  
Forming Process ◽  
Lateral Direction ◽  
Incremental Sheet Metal Forming ◽  
Supporting Tool ◽  
Tool Building

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.

The Simulation of Robot Based Incremental Sheet Metal Forming by Means of a New Solid-Shell Finite Element Technology and a Finite Elastoplastic Model with Combined Hardening

2011 ◽  
Vol 473 ◽  
pp. 875-880 ◽  
Author(s):  
Yalin Kiliclar ◽  
Roman Laurischkat ◽  
Stefanie Reese ◽  
Horst Meier
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Kinematic Hardening ◽  
Industrial Robots ◽  
Solid Shell ◽  
Forming Process ◽  
Incremental Sheet Metal Forming ◽  
Shell Finite Element

The principle of robot based incremental sheet metal forming is based on flexible shaping by means of a freely programmable path-synchronous movement of two tools, which are operated by two industrial robots. The final shape is produced by the incremental infeed of the forming tool in depth direction and its movement along the geometry’s contour in lateral direction. The main problem during the forming process is the influence on the dimensional accuracy resulting from the compliance of the involved machine structures and the springback effects of the workpiece. The project aims to predict these deviations caused by resiliences and to carry out a compensative path planning based on this prediction. Therefore a planning tool is implemented which compensates the robot’s compliance and the springback effects of the sheet metal. Finite element analysis using a material model developed at the Institute of Applied Mechanics (IFAM) [1] has been used for the simulation of the forming process. The finite strain constitutive model combines nonlinear kinematic and isotropic hardening and is derived in a thermodynamical setting. It is based on the multiplicative split of the deformation gradient in the context of hyperelasticity. The kinematic hardening component represents a continuum extension of the classical rheological model of Armstrong–Frederick kinematic hardening which is widely adopted as capable of representing the above metal hardening effects. The major problem of low-order finite elements used to simulate thin sheet structures, such as used for the experiments, is locking, a non-physical stiffening effect. Recent research focuses on the large deformation version of a new eight-node solid-shell finite element based on reduced integration with hourglass stabilization. In the solid-shell formulation developed at IFAM ([2], [3]) the enhanced assumed strain (EAS) concept as well as the assumed natural strain (ANS) concept are implemented to circumvent locking. These tools are very important to obtain a good correlation between experiment and simulation.

Investigation of the ultrasonic vibration effect in incremental sheet metal forming process

2015 ◽  
Vol 231 (6) ◽  
pp. 971-982 ◽  
Author(s):  
Mehdi Vahdati ◽  
Ramezanali Mahdavinejad ◽  
Saeid Amini
Keyword(s):  
Sheet Metal ◽  
Ultrasonic Vibration ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Longitudinal Vibration ◽  
Numerical Control ◽  
Resonance Phenomenon ◽  
Localized Deformation ◽  
Forming Process ◽  
Incremental Sheet Metal Forming

The mechanism of incremental sheet metal forming is based on plastic and localized deformation of sheet metal. The sheet metal is formed using a hemispherical-head tool in accordance with the path programmed into the computer numerical control milling machine controller. Experimental and numerical analyses have been performed previously on the application of ultrasonic vibration to various metal forming processes. However, thus far, the effects of ultrasonic vibration on incremental sheet metal forming have not been investigated. This article presents the process of design, analysis, manufacture and testing of a vibrating forming tool for the development of ultrasonic vibration–assisted incremental sheet metal forming. The results obtained from modal analysis and natural frequency measurement of the vibrating tool confirmed the emergence of a longitudinal vibration mode and resonance phenomenon in the forming tool. Then, the effect of ultrasonic vibration on incremental sheet metal forming was studied. The obtained experimental results from the straight groove test on Al 1050-O sheet metals showed that ultrasonic vibration led to decrease in the following parameters as compared with conventional incremental sheet metal forming: applied force on forming tool axis, spring-back and surface roughness of formed sample.

Experimental investigation into a new hybrid-forming process: Incremental stretch drawing

2016 ◽  
Vol 232 (3) ◽  
pp. 475-486 ◽  
Author(s):  
Puneet Tandon ◽  
Om Namah Sharma
Keyword(s):  
Experimental Investigation ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Lead Time ◽  
Drawing Process ◽  
Forming Process ◽  
Setup Cost ◽  
Deep Drawing Process ◽  
Incremental Sheet Metal Forming

Incremental sheet metal forming is an evolving process, which is suitable for the production of limited quantities of sheet metal components. The main advantages of this process over conventional forming processes are reduced setup cost and manufacturing lead time, as it eliminates the need of special purpose dies, improves formability, reduces forming forces, and provides process flexibility. The objective of this work is to investigate a new hybrid-forming process, which intends to combine incremental sheet metal forming with deep drawing process and has been named as “incremental stretch drawing.” A number of setups and fixtures were developed to carry out experiments to achieve incremental stretch drawing and understand the mechanism of the process. This process addresses some of the challenges of incremental sheet metal forming, that is, limited formability in terms of forming depth, especially at steeper wall angles and subsequent thinning of sheet. It is observed that the proposed process is able to reduce thinning as much as about 300%, considering same forming depth for incremental sheet metal forming and incremental stretch drawing processes. Improvement in formability, in terms of forming depths, also has been observed to be near about 100% in particular cases.

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