Toggle Mechanism Research Articles

A Vector Equation Method for Analyzing Kinematics and Kinetostatics of Toggle-Type Transmission Mechanism

With the help of vector equations and MATLAB software, this paper studied the kinematics and kinetostatics of toggle-type transmission mechanism (hereinafter referred to as “toggle mechanism” for short) and attained the analytical expressions of displacement, speed, and acceleration of slider punch, and the force and moment balance equations of each component in the toggle mechanism with their inertia force taken into consideration. Then, the toggle mechanism was compared with conventional crank-link mechanism and their kinematic characteristics were comparatively analyzed. The proposed kinematics analysis method of toggle mechanism could figure out the kinematic characteristics of the target mechanism and reveal its operating advantages on the basis that its functional requirements are met, in this way, the research purpose of optimizing the design of the mechanism could be realized, and the attained conclusions could provide useful evidence for the design of other types of transmission mechanisms.

Study on dynamic characteristic and forging capacity of the direct drive press with symmetrical toggle booster mechanism driven by TPMLM

Compared with the conventional servo press, the direct drive press even has no transmission mechanism, so it has advantages in controllability, precision and energy management. But, the forging capacity of the direct drive press is limited by the power of the linear motor. In this paper, a novel press driven by a tubular permanent magnet linear motor (TPMLM) is presented, and a symmetrical toggle booster mechanism is specially proposed to enhance the forging capacity. The mathematical model of the toggle booster mechanism is established, The TPMLM is designed, and the experimental prototype of the novel press is manufactured. The forging capacity and dynamic characteristics of the press are studied theoretically and experimentally. The results show that the introduction of the symmetrical toggle booster mechanism enriches the dynamic characteristic curve of the press and enhances the forging capacity. Therefore, the structural parameters of the toggle mechanism and the working position of the slider can be adjusted to meet different technological requirements. In addition, based on the research work, three directions are proposed to improve the forging capacity of the novel press. The research contributes to the performance optimization and development of direct drive press.

Design and analysis of customized mechanisms for various robotic applications: A mini review

Current review deals with the design and analysis of a customized mechanisms for several real life problems. Several simple and complex kinematic mechanisms like 6 leg Robot mechanism, 5- Bar Spherical Mechanism, RP – Chain Mechanism, Flexure Joint Mechanism, Toggle Mechanism, Peaucellier’s – Lipkin Mechanism, flapping wing mechanism etc. are discussed. As the kinematics is concerned with the motion of parts without considering how the influencing factors (force and mass) affect the motion, also the load carrying mechanisms has been a big challenge over the last decades. So the review between several mechanisms is done to get the optimum output. Mathematical equations like Lagrangian equation are used to analyse the DOF of complex customized mechanisms. Major applications of customized mechanism are observed in almost all the fields to ease the existing working procedure. The emphasis is given to highlight the use of advance technologies, computer aided method etc. to enhance the working speed, flexibility, ease in modification and rework cost of any design. The analysis of mechanism is done to develop some innovative business plans according to the product along with the understandings of the current robotic applications. The main future prospective of the current review is to identify several easy methods to customize the existing designs as per the availability of resources like workspace, cost of project, materials, power requirement, level of automation, load bearing capacity, etc. In Future, new entrepreneur ideas can be developed based on the customized mechanism technology.

Deterministic all-optical magnetization writing facilitated by non-local transfer of spin angular momentum

Ever since its discovery around a decade ago, all-optical magnetization switching (AOS) using femtosecond laser pulses has shown potential for future data storage and logic devices. In particular, single pulse helicity independent AOS in certain ferrimagnetic alloys and multilayers is highly efficient and ultrafast. However, in most cases it is a toggle mechanism, which is not desirable for applications. Here we experimentally demonstrate conversion from toggle switching to a deterministic mechanism by biasing AOS in a Co/Gd bilayer with a spin polarized current which is optically generated in an adjacent ferromagnetic reference layer. We show deterministic writing of an ‘up’ and ‘down’ state using a sequence of one or two pulses, respectively, and demonstrate the non-local origin by varying the magnitude of the generated spin current. Our demonstration of deterministic magnetization writing could provide an essential step towards the implementation of future optically addressable spintronic memory devices.

THE STRESS EVALUATION OF THE TOGGLE MECHANISM OF THE THREEPLATEN INJECTION MOLDING MACHINE BY R-F COUPLED MBD MODEL

The aim of the paper is to evaluate the mechanical behavior of the toggle mechanism of an injection mold machine. Different commercial simulation tools were combined to create a rigid-flexible (R-F) coupled multibody (MBD) model for the toggle system of the injection mold machine. Several flexible parts were included by importing the MNF files of the parts generated by the FE model. Then the R-F coupled MBD model of the toggle system were developed in the MBS software. The stress distribution of each component of the toggle system was illustrated. The results show that less stress is loaded at the middle of all the levers. Greater load is applied at the end of the crosshead toggle lever. Finally, some suggestions are given for the lightweight improvement of the toggle system.

EMP: Extended Kalman Filter Based Self-Adaptive Mold Protection Method on a Toggle Mechanism

Nowadays, the plastic injection molding industry is ever-growing, crucial, and its plastic products can be seen everywhere. However, the mold damage problem still frustrates operators because of its high maintenance price and time-consuming maintenance process. This damage is commonly caused by foreign bodies in mold area, and the conventional mold protection method is insufficient for high-performance injection molding machines because of the uncertainty from many setting parameters. To improve detection precision of mold protection driven by a toggle mechanism ( T M ), this paper puts forward E M P , i.e., an extended Kalman filter ( E K F ) based self-adaptive mold protection method, wherein the E K F is used in current curve optimization, and the self-adaptive method ( S A M ) is proposed to gain an safety range of current curve. The E M P was verified in a 140-ton electric injection molding machine. Compared with a general method, the proposed method decreases the detected distance of mold protection by 22% under different thickness foreign bodies.

The buckling beam as actuator element for on-off hydraulic micro valves

The application of buckling beams for two types of micro valve actuation is studied in this paper by mathematical models. The first application type is the magnification of a short stroke actuator, such as piezo-electric stacks, to obtain the required stroke of the valve spool. The second application is the realisation of a spring with negative spring constant as an essential function element of a passive hydraulic binary counter which can control several binary coded valves by one flow control valve. The toggle mechanism as reference solution is mathematically analysed to elucidate the main properties. Four types of beams, only differing by their support structure, are analysed by analytical models employing a Rayleigh-Ritz approach. Models are evaluated to assess the performance properties of these beam types and to provide first order design rules.

High precision control in PTP trajectory planning for nonlinear systems using on high‐degree polynomial and cuckoo search

SummaryIn this paper, in order to fulfill requirements for high precision control, high‐degree polynomial and cuckoo search algorithms are used in point‐to‐point (PTP) trajectory planning for nonlinear systems. The high‐degree polynomial describes the PTP trajectory and the cuckoo search is applied to obtain the coefficients of the high‐degree polynomial with constraints. This method is verified in the hydraulic toggle mechanism. Hamilton's principle and a Lagrange multiplier help establish the dynamic and kinematic equations in the hydraulic toggle mechanism. Position accuracy and the convergence effect of different degrees of polynomials are then compared through experiment. Specifically, this paper discusses the error of the 8‐degree polynomial trajectory between the optimization and practical values and the repeated accuracy of the optimization trajectory, which verify the method's high precision control in regard to the PTP trajectory planning for nonlinear system proposed in this paper. This method could be used in any type of PTP trajectory planning for nonlinear system.

Numerical and Experimental Design Optimization of Toggle Clamping Mechanism

Toggle mechanism is commonly used in manufacturing industry for several applications ranging from injection molding machines to tools and fixtures. Toggle clamps are available in numerous types to outfit specific applications. This paper explores the design optimization of the toggle clamping mechanism. Toggle mechanism considered here is actuated by hydraulic cylinder used in CNC bending machines. Force amplification ratio is the key design parameter of toggle clamping mechanism. Performance of toggle clamp mechanism is based upon the force available at the clamping location which is output link. Clamping force available at the output link is the function of the input cylinder force, geometric position of all the links, coefficient of friction between moving and turning parts. Hydraulic cylinder is available in different standard sizes and is operated on specific system pressure. Input cylinder force is the function of cylinder size and the system operating pressure. Mathematical modeling of the toggle clamp mechanism is presented in this paper. Analytical approach and computer-aided design model force analysis are also carried out. Resulting clamping force computed from the analytical approach is compared with the CAD model analysis. The ultimate aim of this work is to develop a new toggle mechanism to reduce the input efforts to get the same output as in existing toggle clamping mechanism.

Design and optimization of a robotic gripper for the FEM assembly process of vehicles

The FEM (Front End Module) assembly process consists of lifting, positioning, and bolt tightening procedures in the automotive assembly line. This process requires operations for handling heavy objects precisely and repetitively. Powered wearable robots, which are regarded as human-robot cooperation systems, are expected to solve the difficulties and improve the productivity by combining the power of robots and human intelligence. Grippers are required for performing processes by a wearable robot, but conventional grippers or overhead type loaders cannot be used for this application in terms of their weight, size, and gripping force. Thus, we focused on the design of a special gripper for a wearable robot. A six-bar linkage incorporating a toggle mechanism is employed to reduce the overall weight of the gripper while maximizing the gripping force. For gripping a FEM over a wide operating range, it is necessary to follow the desired coupler path. To satisfy the requirements of both coupler path and drive torque, a multi-objective optimization approach is introduced. As a result, an optimum design is selected from the Pareto front, which satisfies the requirements of path tracking and torque capacity.

The Design and Fabrication of Crushing Machine Using Double Toggle Mechanism

The Design and Fabrication of Crushing Machine Using Double Toggle Mechanism

電磁アクチュエータとトグル機構を用いた高速・高分解能インチワーム

電磁アクチュエータとトグル機構を用いた高速・高分解能インチワーム

High-speed and High-resolution Linear Microstepper Based on Toggle Mechanism Actuated by Electromagnet

High-speed and High-resolution Linear Microstepper Based on Toggle Mechanism Actuated by Electromagnet

High mechanical advantage design of six-bar Stephenson mechanism for servo mechanical presses

This article proposed a two-phase design scheme of Stephenson six-bar working mechanisms for servo mechanical presses with high mechanical advantage. In the qualitative design phase, first, a Stephenson six-bar mechanism with a slide was derived from Stephenson six-bar kinematic chains. Second, based on the instant center analysis method, the relationship between mechanical advantage and some special instant centers was founded, and accordingly a primary mechanism configuration with high mechanical advantage was designed qualitatively. Then, a parameterized prototype model was established, and the influences of design parameters toward slide kinematical characteristics were analyzed. In the quantitative design phase, a multi-objective optimization model, aiming at high mechanical advantage and dwelling characteristics, was built, and a case design was done to find optimal dimensions. Finally, simulations based on the software ADAMS were conducted to compare the transmission characteristics of the optimized working mechanism with that of slide-crank mechanism and symmetrical toggle mechanism, and an experimental press was made to validate the design scheme. The simulation and experiment results show that, compared with general working mechanisms, the Stephenson six-bar working mechanism has higher mechanical advantage and better dwelling characteristics, reducing capacities and costs of servo motors effectively.

Mathematical modelling and two-stage identification for a motor–toggle mechanism with clamping effect

The effect of clamping forces on a motor–toggle mechanism is dynamically modeled in this paper, and the clamping unit is presented by a simple spring-damper model. Based on real practical applications, the impact force model (IFM) associated with clamping effectiveness must be considered during the process of clamping. A two-stage identification method is also needed to develop for validating dynamic responses of the unclamping and clamping motions. The real-coded genetic algorithm (RGA) is employed to obtain system's parameters by two different fitness functions. The RGA feasibility is verified by the assigned parameters in numerical simulations, and then applied to the experimental physical model. Finally, numerical simulations and experimental results showed good agreement, and the proposed two-stage identification method described in this paper is found to be both better and necessary for the mechatronic system with a clamping unit.

Design of a micro machine tool with double-toggle mechanisms

Micro machining plays an important role in manufacturing the miniature products which are made of various materials with complex 3D shapes and tight machining tolerance. In this paper, a new design of CNC micro machine tool with double-toggle mechanism is proposed. The machine has the characteristics of low cost, ultra-fine feed resolution, and high accuracy. With the double-toggle mechanism and regular driving components including AC motors, ballscrews, and a PC-based controller, the micro machine tool can perform good micro machining for miniature components. Because of the geometrical drive function, the errors of the machine are reduced by the double toggle structure without using high-end driving components and controller. In addition, the design of the structure avoids the drawback of the regular toggle mechanism which cannot have stable feed resolution for the full travel range. The kinematics model and characteristics of the machine were derived and analyzed. Modal analysis and dynamic compliance analysis were also conducted to evaluate stiffness and dynamic characteristics of the machine. A prototype of the machine was built, and the accuracy calibration results showed the machine can reach a positioning accuracy of 470nm.

Computer Aided Kinematic Analysis of Toggle Clamping Mechanism

Toggle mechanism is used widely in the mechanical industry for various applications ranging from injection molding machines to tools & fixtures. Toggle clamps are available for different types to suit desired application. This paper explores the kinematic analysis of the toggle clamping mechanism. Toggle mechanism considered here is actuated by hydraulic cylinder. Position, velocity and acceleration analysis is described in this work, for this analysis toggle clamping mechanism is fragmented into two basic mechanisms, Slider-Crank mechanism and Four-Bar Mechanism. Slider-Crank generates torque and output force in the toggle clamp mechanism so emphasis is given on slider-crank mechanism in this work. Toggle clamp mechanism for work- piece bending operation is described in this work. Mechanical advantage of the linkage is the key parameter for linkage performance, mechanical advantage and it's relation with torque and link parameter is discussed in brief.

Adaptive Tracking Control of a PMSM-Toggle System with a Clamping Effect

This paper discusses an adaptive control (AC) designed to track an energy-saving point-to-point (ESPTP) trajectory for a mechatronic system, which is a toggle mechanism driven by a permanent magnet synchronous motor (PMSM) with a clamping unit. To generate the PTP trajectory, we employed an adaptive real-coded genetic algorithm (ARGA) to search for the energy-saving trajectory for a PMSM-toggle system with a clamping effect. In this study, a high-degree polynomial was used, and the initial and final conditions were taken as the constraints for the trajectory. In the ARGA, the parameters of the polynomials were determined by satisfying the desired fitness function of the input energy. The proposed AC was established by the Lyapunov stability theory in the presence of a mechatronic system with uncertainties and the impact force not being exactly known. The trajectory was tracked by the AC in experimental results so as to be compared with results produced by trapezoidal and high-degree polynomials during motion.

10–25 GHz frequency reconfigurable MEMS 5-bit phase shifter using push–pull actuator based toggle mechanism

This paper presents a frequency tunable 5-bit true-time-delay digital phase shifter using radio frequency microelectromechanical system (RF MEMS) technology. The phase shifter is based on the distributed MEMS transmission line (DMTL) concept utilizing a MEMS varactor. The main source of frequency tuning in this work is a bridge actuation mechanism followed by capacitance variation. Two stages of actuation mechanisms (push and pull) are used to achieve a 2:1 tuning ratio. Accurate control of the actuation voltage between the pull to push stages contributes differential phase shift over the band of interest. The functional behavior of the push–pull actuation over the phase shifter application is theoretically established, experimentally investigated and validated with simulation. The phase shifter is fabricated monolithically using a gold based surface micromachining process on an alumina substrate. The individual primary phase-bits (11.25°/22.5°/45°/90°/180°) that are the fundamental building blocks of the complete 5-bit phase shifter are designed, fabricated and experimentally characterized from 10–25 GHz for specific applications. Finally, the complete 5-bit phase shifter demonstrates an average phase error of 4.32°, 2.8°, 1° and 1.58°, an average insertion loss of 3.76, 4.1, 4.2 and 4.84 dB and an average return loss of 11.7, 12, 14 and 11.8 dB at 10, 12, 17.2 and 25 GHz, respectively. To the best of the authors’ knowledge, this is the first reported band tunable stand alone 5-bit phase shifter in the literature which can work over the large spectrum for different applications. The total area of the 5-bit phase shifter is 15.6 mm2. Furthermore, the cold-switched reliability of the unit cell and the complete 5-bit MEMS phase shifter are extensively investigated and presented.

Structure of an ADP-ribosylation factor, ARF1, from Entamoeba histolytica bound to Mg(2+)-GDP.

Entamoeba histolytica is the etiological agent of amebiasis, a diarrheal disease which causes amoebic liver abscesses and amoebic colitis. Approximately 50 million people are infected worldwide with E. histolytica. With only 10% of infected people developing symptomatic amebiasis, there are still an estimated 100,000 deaths each year. Because of the emergence of resistant strains of the parasite, it is necessary to find a treatment which would be a proper response to this challenge. ADP-ribosylation factor (ARF) is a member of the ARF family of GTP-binding proteins. These proteins are ubiquitous in eukaryotic cells; they generally associate with cell membranes and regulate vesicular traffic and intracellular signalling. The crystal structure of ARF1 from E. histolytica has been determined bound to magnesium and GDP at 1.8 Å resolution. Comparison with other structures of eukaryotic ARF proteins shows a highly conserved structure and supports the interswitch toggle mechanism of communicating the conformational state to partner proteins.