Geometric Optimization of the Five-Point Double-Toggle System for the Clamping Unit of an Injection Molding Machine with the Response Surface Method
Received: 12 September 2024 | Revised: 9 October 2024 | Accepted: 13 October 2024 | Online: 1 November 2024
Corresponding author: Huu Loc Nguyen
Abstract
Injection molding is one of the most used processes for the manufacture of plastic products with high-volume capacity. The five-point double toggle mechanism is frequently employed in the clamping unit to augment the force generated by a linear actuator, thereby achieving the requisite clamping force. This is a crucial aspect that determines the productivity and quality of the finished product in the injection molding process. Nevertheless, the geometrical synthesis of this type of mechanism has not been sufficiently addressed with regard to its integration into the mold design and the opening/closing stroke. This paper presents a novel approach for analyzing and evaluating the impact of parameters pertaining to mechanism posture on its force amplification, employing the Taguchi method. The relationship between force amplification ratio and the most influential parameters is simplified with the Face-Centered Central Composite Design (FCCCD) method, thereby allowing the optimal posture of the mechanism at the mold-closing stage to be determined. With these optimal parameters, once the mold height and desired opening/closing stroke have been selected, the dimensions of the links in the mechanism can be calculated. The results demonstrate that there are numerous combinations of these parameters that can yield a high force amplification ratio, thus providing the designer with a range of options for the design of a clamping unit. The proposed method can be employed at the initial stage of the design process to obtain a preliminary design, thus preparing for the dynamic analysis or further optimization problems of the mechanism.
Keywords:
injection molding, clamping mechanism, Taguchi method, five-point, double toggle mechanism, Face-Centered Central Composite Design (FCCCD)Downloads
References
F. Johannaber, "The Clamping Unit," in Injection Molding Machines, Munich, Germany: Carl Hanser Verlag GmbH & Co. KG, 2007, pp. 145–176.
R. Fung Fong, C. Hwang Chuan, C. Huang Sen, and W.-P. Chen, "Inverse dynamics of a toggle mechanism," Computers & Structures, vol. 63, no. 1, pp. 91–99, Apr. 1997.
N. Zhao, Z. Xu, Y. Shan, H. Zhou, and X. Huang, "The constant/variable kinematics adjustment of the crosshead and the mold’s stability management in injection molding," The International Journal of Advanced Manufacturing Technology, vol. 133, no. 1, pp. 901–912, Jul. 2024.
X. Chen and S. Jiang, "Nonlinear dynamic behavior analysis of multi-linkage mechanism with multiple lubrication clearances," European Journal of Mechanics - B/Fluids, vol. 91, pp. 177–193, Jan. 2022.
W. Chang Tung, W. I. Lee, and K. L. Hsu, "Analysis and Experimental Verification of Mechanical Errors in Nine-Link Type Double-Toggle Mold/Die Clamping Mechanisms," Applied Sciences, vol. 11, no. 2, p. 832, Jan. 2021.
Z. He et al., "Research on dynamics model of the motion clamping mechanism in injection molding machines addressing inertia and deformation," Journal of Manufacturing Processes, vol. 119, pp. 987–1004, Jun. 2024.
W. Y. Lin and K. M. Hsiao, "Study on improvements of the five-point double-toggle mould clamping mechanism," Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, vol. 218, no. 7, pp. 761–774, Jul. 2004.
W. Y. Lin, C. L. Shen, and K. M. Hsiao, "A Case Study of the Five-Point Double-Toggle Mould Clamping Mechanism," Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, vol. 220, no. 4, pp. 527–535, Apr. 2006.
W. Y. Lin and S. S. Wang, "Dimensional synthesis of a five-point double-toggle mould clamping mechanism using a genetic algorithm—differential evolution hybrid algorithm," Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, vol. 224, no. 6, pp. 1305–1313, Jun. 2010.
M. S. Huang, T. Y. Lin, and R. F. Fung, "Key design parameters and optimal design of a five-point double-toggle clamping mechanism," Applied Mathematical Modelling, vol. 35, no. 9, pp. 4304–4320, Sep. 2011.
L. C. Hsieh, T. H. Chen, and P. C. Lai, "The kinematic design of mold clamping mechanism with minimal maximum acceleration," Advances in Mechanical Engineering, vol. 12, no. 6, p. 1687814020926280, Jun. 2020.
L. C. Hsieh, T. H. Chen, and P. C. Lai, "Dimensional Synthesis and Kinematic Analysis of Mold Clamping Mechanism with Double Toggle Effects at Clamped Position," Applied Mechanics and Materials, vol. 900, pp. 27–34, 2020.
L. C. Hsieh, T. H. Chen, P. C. Lai, and S. W. Zheng, "Optimal design on Watt-chain double-toggle mold clamping mechanism for injection molding machine," Science Progress, vol. 104, no. 3, Sep. 2021, Art. no. 368504211041488.
V.-D. Le et al., "Computational study on the clamping mechanism in the injection molding machine," The International Journal of Advanced Manufacturing Technology, vol. 121, no. 11, pp. 7247–7261, Aug. 2022.
M. Tanase, D. G. Zisopol, and A. I. Portoaca, "A Study regarding the Technical-Economical Optimization of Structural Components for enhancing the Buckling Resistance in Stiffened Cylindrical Shells," Engineering, Technology & Applied Science Research, vol. 13, no. 5, pp. 11511–11516, Oct. 2023.
B. Paul, Kinematics and Dynamics of Planar Machinery. Englewood Cliffs, NJ, USA: Prentice Hall, 1979.
EUROMAP 2, Injection moulding machines - Mould fixing and connection dimensions. Technical Commission of European Committee of Machinery Manufacturers for the Plastics and Rubber Industries, 1996.
Downloads
How to Cite
License
Copyright (c) 2024 Thien Bao Ho, Huu Loc Nguyen
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with this journal agree to the following terms:
- Authors retain the copyright and grant the journal the right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) after its publication in ETASR with an acknowledgement of its initial publication in this journal.
