In deep drawing, a low blank holder force (BHF) can cause wrinkling, while a high BHF can lead to tearing. Thus, it is important to determine the appropriate BHF to be utilized in the forming process. In this study, a variable blank holder force (VBHF) approach to deep drawing is employed, and a simple closed-loop type algorithm is developed to obtain the VBHF trajectory.The proposed algorithm is divided into two phases. The objective of the first phase is to check wrinkling and tearing. In this phase, a low BHF, which is the causes of wrinkling, is used as the initial BHF; it is then increased to prevent wrinkling. The algorithm is terminated when tearing occurs. In a numerical simulation, the distance between the die and the blank holder is used to measure wrinkling. On the other hand, the thickness of the blank is used to determine the tearing.Next, in the second phase, the deviations in thickness are examined. Wrinkles are also checked in the second phase. By iterating the above two phases, the VBHF trajectory can be obtained. One of the advantages of the VBHF is that it reduces the forming energy. The validity of the proposed algorithm is examined through both a numerical simulation and experiment.

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3D printers that use the fused deposition modeling (FDM) method are generally based on a three-linear-axis mechanism. However, because the posture of the workpiece is limited, the shape of the model that can be generated by this type of 3D printer is restricted. The 3D printer makes 3D models by stacking up materials on a plane. Because of this principle, a base to support the laminated material is necessary, and it is impossible to develop a model shape with an overhang without support parts. Although the problem is solved by making a foundation using a support material, it takes time to shape and remove the material. Therefore, this conventional method is time consuming. The purpose of this research is to laminate and make shapes that are difficult to laminate with a three-axis 3D printer without using support material. Therefore, a new five-axis 3D printer was developed with the FDM method, and its control program was designed. In addition, hardware consisting of the mechanical structure and the servo control system was developed, and the laminating path, which can exert the effect of the five-axis mechanism, was calculated. The posture of the workpiece can be controlled by mounting the B-axis, which tilts the lamination table, and the C-axis, which rotates the lamination table added on the three-axis configuration 3D printer. Furthermore, a five-axis synchronization control program was developed to control the motion of the five-axis synchronous motion. Furthermore, to correct the nozzle position due to the posture change of the workpiece, a mathematical model of shape creation theory was applied to derive the offset command value. As a result of the laminating experiments of the overhang shape model, the five-axis mechanism and laminating path were sufficiently effective, and the five-axis synchronous control of the 3D printer demonstrated the creation of the overhang shape. However, in experiments using a conventional three-axis mechanism 3D printer with the same lamination path, resins did not adhere and dripped, making shaping impossible. Because of these results, the machining time of the five-axis controlled 3D printers was shorter than that of conventional three-axis-controlled 3D printers. Here, the basic configurations and control system are reported.

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