FlexDie: A Flexible Tooling-Concept for Incremental Sheet Forming

2012 ◽  
Vol 504-506 ◽  
pp. 883-888 ◽  
Author(s):  
Gerd Sebastiani ◽  
Arthur Wawrosch ◽  
Volker Franzen ◽  
Alexander Brosius ◽  
A. Erman Tekkaya

Forming tasks in Sheet Metal Prototyping are currently a balancing act between part flexibility and accuracy. In view of Asymmetric Incremental Sheet Forming (AISF), the part support is the decisive factor: Die-based processes such as TPIF are restricted to the given geometry of the part. On the other hand, the die-less variant (SPIF) is prone to a much more complex process-layout – once a similar accuracy needs to be obtained. Consequently, this requires a flexible die concept, supporting the part in the critical zones only. Within this article we meet this challenge by introducing the configurable tooling concept "FlexDie". This support tool comprises a construction kit for skeleton dies allowing for an adjustment of its geometry to almost any desired shape. Based on the solar cooker benchmark by Jeswiet et al., we show both the tooling-concept and the feasibility. The latter we discuss, based on the quality features geometric accuracy as well as surface quality. Both features are assessed with respect to the forming results obtained by use of a full-die. The accuracy resulting by applying the FlexDie is only slightly inferior to the parts formed by use of a full-die. However, the FlexDie allows for simple optimization of both, die and part geometry. In addition, compensation strategies by adapting the toolpath are still possible. In summary, the results show the feasibility of the FlexDie concept for industrial ISF tasks - even at very low production volumes.

2017 ◽  
Vol 31 (11) ◽  
pp. 5257-5264 ◽  
Author(s):  
Lihua Li ◽  
Jin Wang ◽  
Baoping Wang

Author(s):  
Rui Xu ◽  
Huaqing Ren ◽  
Zixuan Zhang ◽  
Rajiv Malhotra ◽  
Jian Cao

Incremental sheet forming has attracted considerable attention in the recent past due to advantages that include high process flexibility and higher formability as compared to conventional forming processes. However, attaining required geometric accuracy of the formed part is one of the major issues plaguing this process. The Double-Sided Incremental Forming process has emerged as a potential process variant which can preserve the process flexibility while maintaining required geometric accuracy. This paper investigates a mixed toolpath for Double-Sided Incremental Forming which is able to simultaneously achieve good geometric accuracy and higher throughput than is currently possible. The geometries of parts formed using the mixed toolpath strategy are compared to the desired geometry. Furthermore, an examination of the forming forces is used to uncover the reasons for experimentally observed trends. Future work in this area is also discussed.


2016 ◽  
Vol 716 ◽  
pp. 395-401 ◽  
Author(s):  
Jan Brüninghaus ◽  
Yan Volfson ◽  
Jobst Bickendorf ◽  
Sigrid Brell-Cokcan

The formability and geometrical accuracy in incremental sheet forming can be increased using a force-controlled support tool. The main problems in using such a kinematic support tool is the positioning of forming and support tools, while maintaining force magnitude and alignment. A new tool for this was developed systematically using a morphological box. It uses a spring controlled rotation of the tool tip to maintain the force. Since the rotation axis is not in line with the tool tip axis and the tool tip can freely rotate around its axis, roll friction conditions can be achieved. The center of gravity of the rotating part of the tool is placed in the rotating axis and the force is therefore independent from the alignment of the tool in space. It has a mechanical stop with locking option in the vertical position and is therefore also fully usable as a forming tool. While the prototype is manually controlled, concepts for a fully automated version have been designed, as well. First tests are in line with results described in literature, showing that direction and magnitude of force have an influence on the formability.


2017 ◽  
Author(s):  
Michael Rieger ◽  
Denis Daniel Störkle ◽  
Lars Thyssen ◽  
Bernd Kuhlenkötter

2014 ◽  
Vol 622-623 ◽  
pp. 382-389 ◽  
Author(s):  
Antonio Fiorentino ◽  
G.C. Feriti ◽  
Elisabetta Ceretti ◽  
C . Giardini ◽  
C.M.G. Bort ◽  
...  

The problem of obtaining sound parts by Incremental Sheet Forming is still a relevant issue, despite the numerous efforts spent in improving the toolpath planning of the deforming punch in order to compensate for the dimensional and geometrical part errors related to springback and punch movement. Usually, the toolpath generation strategy takes into account the variation of the toolpath itself for obtaining the desired final part with reduced geometrical errors. In the present paper, a correction algorithm is used to iteratively correct the part geometry on the basis of the measured parts and on the calculation of the error defined as the difference between the actual and the nominal part geometries. In practice, the part geometry is used to generate a first trial toolpath, and the form error distribution of the resulting part is used for modifying the nominal part geometry and, then, generating a new, improved toolpath. This procedure gets iterated until the error distribution becomes less than a specified value, corresponding to the desired part tolerance. The correction algorithm was implemented in software and used with the results of FEM simulations. In particular, with few iterations it was possible to reduce the geometrical error to less than 0.4 mm in the Incremental Sheet Forming process of an Al asymmetric part, with a resulting accuracy good enough for both prototyping and production processes.


2015 ◽  
Vol 639 ◽  
pp. 535-542 ◽  
Author(s):  
Bin Lu ◽  
Dong Kai Xu ◽  
Run Zhe Liu ◽  
Heng An Ou ◽  
Hui Long ◽  
...  

Incremental sheet forming (ISF) is a highly versatile and flexible process for rapid manufacturing of complex sheet metal parts. Comparing to conventional sheet forming processes, ISF is of a clear advantage in manufacturing small batch or customized products such as cranial implant. Although effort on cranial reconstruction by using incremental sheet forming approach has been made in recent years, research has been mostly based on the single point incremental forming (SPIF) strategy and there are still considerable technical challenges for achieving better geometric accuracy, thickness distribution and complex cranial shape. In addition, the use of a backing plate or supporting die reduces the process flexibility and increases the cost. To overcome these limitations, double side incremental sheet forming (DSIF) process is employed for forming Grade 1 pure titanium sheet by using different toolpath strategies. The geometric accuracy and thickness distribution of the final part are evaluated so the optimized tool path strategies are developed. This leads to an assessment of the DSIF based approach for the application in cranial reconstruction.


2022 ◽  
Author(s):  
Weining Li ◽  
Khamis Essa ◽  
Sheng Li

Abstract For heat-assisted single point incremental sheet forming (SPIF) works of Ti-6Al-4V sheets, the use of lubricant has shown significant effects on surface quality and geometric accuracy at higher temperatures. Molybdenum disulphide (MoS2) is a common lubricant widely used in SPIF works, however, it usually indicates ineffective performance at high temperatures. This article has studied different lubricants of MoS2 lubricants and proposed a novel mixture of MoS2 to provide better surface quality and improve geometric accuracy. A forming tool with a ball-roller and water channel was designed to enable the MoS2 mixture to pass through the tool tip, allowing easy application of the lubricant on the localised area and reduce the thermal expansion on the ball-roller. Surface roughness analysis has revealed that the water-cooling MoS2 mixture performed well in reducing friction effects and achieved better geometric accuracy. Forming forces measurements, scanning electron microscope (SEM), energy dispersive X-ray Analysis (EDX) and micro-hardness tests also indicated that a higher strain hardening behaviour was detected for the water-cooling MoS2 mixture.


2020 ◽  
Vol 111 (1-2) ◽  
pp. 565-587
Author(s):  
Hui Zhu ◽  
Hengan Ou ◽  
Atanas Popov

Abstract Incremental sheet forming (ISF) is a promising flexible manufacturing process, which has been tested in sheet forming of various metallic materials. Although ISF-based forming of thermoplastics is relatively new, it has drawn considerable interests and significant progress has been made in recent years. This paper presents a review of concurrent research on the emerging trend of thermoplastic-focused ISF processes. Attention is given to the processing conditions including process setup, process parameters and forming forces. The deformation mechanism and failure behaviour during ISF of thermoplastics are evaluated, which leads to detailed discussions on the formability, effect of different process parameters and the forming quality such as geometric accuracy, surface finish and other consideration factors in ISF of thermoplastics. A comparison of important similarities and differences between ISF of thermoplastic and metallic materials is made. Finally, a brief discussion is provided on the technical challenges and research directions for ISF of thermoplastic materials in the future.


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