The Kinematics Analysis and Study on Triangular Elbow Servo Press

2011 ◽  
Vol 121-126 ◽  
pp. 1636-1640
Author(s):  
Ying Qiu ◽  
Wei Min Li ◽  
Zhi Wei

Servo presses are widely used in high-precision, complicated forming process fields and promoted around the world in recent years. It is the trend of forging machinery for its servo motor-based digital heavy haul driven technology. At present, it becomes the hot research field. The structure characteristics of triangular elbow servo press were firstly introduced in the paper. And then the kinematics mathematical model of triangular elbow transmission mechanism was deduced and given. Based on it, this paper provides the slider kinematics analysis by Matlab. The slider motion law under various parameters can be analyzed and compared. The results would be useful reference for optimization design of transmission mechanism. The case study provides more visual and reliable decision basis for designer.

2014 ◽  
Vol 577 ◽  
pp. 240-243
Author(s):  
Ying Qiu ◽  
Wei Min Li ◽  
Zhi Wei

The objective of this paper is to study performance of triangular elbow transmission mechanism for servo press. Then kinematics models are deduced and given. Kinematics curves along slider motion direction are drawn. Moreover, under the same driving condition, the effects of different link ratios on slider output motion are examined and compared with common six bar transmission mechanism in the article. Through motion curves comparison, it can be seen that this triangular elbow mechanism has significant force increasing effect and good quick-return characteristics. In addition, we carried on triangular elbow servo press virtual design and simulation. The case study provides more visual and reliable decision basis for designer. The results would be useful reference for optimization design of transmission mechanism.


2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jianneng Chen ◽  
Xincheng Sun ◽  
Chuanyu Wu ◽  
Dadu Xiao ◽  
Jun Ye

AbstractThe noncircular synchronous belt drive mechanism has demonstrated certain achievements and has been used in special fields. Research regarding noncircular synchronous belt drive mechanisms has focused on optimization design and kinematic analysis in China, whereas two pulley noncircular synchronous belt transmissions have been developed overseas. However, owing to the noncircular characteristics of the belt pulley, the real-time variation in the belt length slack during the transmission of the noncircular synchronous belt is significant, resulting in high probabilities of skipping and vibration. In this study, a noncircular tensioning pulley is added to create a stable three-pulley noncircular synchronous belt driving mechanism and a good synchronous belt tensioning, with no skipping; hence, the non-uniform output characteristic of the driven pulley is consistent with the theoretical value. In the circular noncircular noncircular three-pulley noncircular synchronous belt mechanism, the pitch curve of the driving synchronous belt pulley is circular, whereas those of the driven synchronous belt and tensioning pulleys are noncircular. To minimize the slack of the belt length of the synchronous belt and the constraint of the concavity and circumference of the tensioning pulley, an automatic optimization model of the tensioning pulley pitch curve is established. The motion simulation, analysis, and optimization code for a three-belt-pulley noncircular synchronous belt drive mechanism is written, and the variation in belt length slack under different speed ratios is analyzed based on several examples. The testbed for a circular–noncircular–noncircular three-pulley noncircular synchronous belt transmission mechanism is developed. The test shows that the three-pulley noncircular synchronous belt drives well. This study proposes an automatic optimization algorithm for the tensioning pulley pitch curve of a noncircular synchronous belt transmission mechanism; it yields a stable transmission of the noncircular synchronous belt transmission mechanism as well as non-uniform output characteristics.


Author(s):  
Christof Paulus ◽  
Albert Weber

AbstractVenice is considered the best-informed community of the late Middle Ages. The study examines the availability of information for the second half of the 15th century, particularly with regard to the key year 1462/1463, and as a case study concentrates on areas of the supposed Venetian periphery of interest, above all Hungary and the two principalities of Wallachia and Moldavia. The result is a thoroughly differentiated system of information acquisition, verification and control. Means of communication, as well as different areas of interest of the Serenissima, can be identified. A distinction is made between information maps and communication maps. The latter also include the distribution of news from the lagoon city exchanged with foreign envoys. During the period concerned, news was exchanged in an astonishingly liberal way, in turn integrating the Serenissima into the information networks of the other Italian states. The study thus places the „information commodity“ within the research field of late medieval gift exchange and patronage structures. In short, a thoroughly pragmatic Venetian approach to news acquisition and evaluation can be observed. Verification of the quality of the information obtained was subject not least to quantitative and ranking criteria. Ultimately, the informational power of Venice was based above all on its outstanding reputation among its contemporaries.


2021 ◽  
Vol 11 (1) ◽  
pp. 294-302
Author(s):  
Gal Davidi

Abstract In this work an analysis of the radial stress and velocity fields is performed according to the J 2 flow theory for a rigid/perfectly plastic material. The flow field is used to simulate the forming processes of sheets. The significant achievement of this paper is the generalization of the work by Nadai & Hill for homogenous material in the sense of its yield stress, to a material with general transverse non-homogeneity. In Addition, a special un-coupled form of the system of equations is obtained where the task of solving it reduces to the solution of a single non-linear algebraic differential equation for the shear stress. A semi-analytical solution is attained solving numerically this equation and the rest of the stresses term together with the velocity field is calculated analytically. As a case study a tri-layered symmetrical sheet is chosen for two configurations: soft inner core and hard coating, hard inner core and soft coating. The main practical outcome of this work is the derivation of the validity limit for radial solution by mapping the “state space” that encompasses all possible configurations of the forming process. This configuration mapping defines the “safe” range of configurations parameters in which flawless processes can be achieved. Several aspects are researched: the ratio of material's properties of two adjacent layers, the location of layers interface and friction coefficient with the walls of the dies.


2014 ◽  
Vol 622-623 ◽  
pp. 956-963 ◽  
Author(s):  
Luca Giorleo ◽  
Elisabetta Ceretti ◽  
Claudio Giardini

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Since each roll is characterized by a speed law that can be set independently by the speed law imposed to the other rolls, an optimization is more critical compared with other deformation processes. Usually, in industrial environment, a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization. In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speed laws (linearly decreasing, constant, linearly increasing) were designed and simulated. The results were compared in order to identify the best milling curve that guarantees a good quality ring (higher diameter, lower fishtail) with lower loads and energy required for manufacturing.


Author(s):  
Chen Liu ◽  
Sheng-Dun Zhao ◽  
Jing-Xiang Li

This paper proposes a novel high capacity servo press system with two servo motor inputs and high ratio force amplifier mechanism for metal forming. First, the press structure was expressed. The force amplifier was made of seven-bar mechanism which possesses quick-return character and high ratio force amplifier. The symmetric structure balanced the force in horizontal direction, and dispersed the forces on two transmission routes. In theoretical study of the new structure, kinematic and dynamic analyses were obtained by examining the geometry of the structure. The performance of press was discussed by example demonstration. Finally, the kinematic experiments and metal forming experiments were carried out on the prototype machine by using grating scale system. The measured data match the theoretical calculation well, which validates the feasibility of this new press mechanism.


Author(s):  
Jing Tao ◽  
Huanan Qian ◽  
Suiran Yu

The accuracy of machine is important to achieving highly accurate shapes. This paper is focused on mechanical design of highly accurate mechanical linkage servo press applicable to (near-)net shape forming. The effects of geometric errors, deformations under heavy loads and ram tilting are analyzed. A top-down design for accuracy approach is proposed: First, accuracy model for identification of inaccuracy-causing factors and their interlinking relations is developed. Then, based on this model, top accuracy index are decomposed and translated into structure design specifications at component level. Both analytic and simulation methods are employed for design for accuracy in aspects of dimensional and geometric tolerance allocation, stiffness synthesis and anti-eccentric load capability. A case study of mechanical design for accuracy of a six-linkage mechanical servo press is also presented to demonstrate and test the proposed design approaches.


2021 ◽  
Vol 2042 (1) ◽  
pp. 012116
Author(s):  
Pierson Clotilde ◽  
Soto Magán Victoria Eugenia ◽  
Aarts Mariëlle ◽  
Andersen Marilyne

Abstract Recent developments in the lighting research field have demonstrated the importance of a proper exposure to light to mediate several of our behavioral and physiological responses. However, we spend nowadays around 90% of our time indoors with an often quite limited access to bright daylight. To be able to anticipate how much the built environment actually influences our light exposure, and how much it may ultimately impact our health, well-being, and productivity, new computational tools are needed. In this paper, we present a first attempt at a simulation workflow that integrates a spectral simulation tool with a light-driven prediction model of alertness. The goal is to optimize the effects of light on building occupants, by informing the decision makers about the impact of different design choices. The workflow is applied to a case study to provide an example of what learnings can be expected from it.


2019 ◽  
Vol 06 (03n04) ◽  
pp. 2050009
Author(s):  
Jayne Lino ◽  
Guillaume Rohat ◽  
Paul Kirshen ◽  
Hy Dao

Climate change will impact cities’ infrastructure and urban dwellers, who often show differentiated capacity to cope with climate-related hazards. The Shared Socioeconomic Pathways (SSPs) are part of an emerging research field which uses global socioeconomic and climate scenarios, developed by the climate change research community, to explore how different socioeconomic pathways will influence future society’s ability to cope with climate change. While the SSPs have been extensively used at the global scale, their use at the local and urban scale has remained rare, as they first need to be contextualized and extended for the particular place of interest. In this study, we present and apply a method to develop multi-scale extended SSPs at the city and neighborhood scale. Using Boston, Massachusetts, as a case study, we combined scenario matching, experts’ elicitation, and participatory processes to contextualize and make the global SSPs relevant at the urban scale. We subsequently employed the extended SSPs to explore future neighborhood-level vulnerability to extreme heat under multiple plausible socioeconomic trajectories, highlighting the usefulness of extended SSPs in informing future vulnerability assessments. The large differences in outcomes hint at the enormous potential of risk reduction that social and urban planning policies could trigger in the next decades.


Sign in / Sign up

Export Citation Format

Share Document