Toggle Clamping Research Articles

Perencanaan Perawatan Mesin Injection Molding Dengan Menggunakan Metode Realibility Centered Maintenance PT. Bolde Makmur Indonedia

The instability of the economy and increasingly sharp competition in the industry requires a company to further enhance the efficiency of its operations. Treatment method that has been used is still corrective maintenance where engine maintenance activities undertaken to improve and enhance the condition of the engine so as to achieve the standards set at the level tersebut.Besarnya machine downtime which reaches up to 40% each month. Due to the growing number of downtime that occurs it will be increasingly detrimental to the productivity of a company. In this study used methods Realibility Centered Maintenance abbreviated to (RCM), which is to determine the optimal engine maintenance activities for the company. Reliability Centered Maintenance (RCM) is an approach that combines maintenance practices and strategies of preventive maintenance (PM) and corrective maintenance (cm) to maximize the life (life time) and the function of assets / systems / equipment at a minimal cost. Subjects studied machine is the machine Injection Molding, where the focus of engine components that will be examined as many as six parts: Barrel, Piston Injection, Toggle Clamping, Nozzle, Hydro Motor, Hopper. As for the category based on time (TD), the treatment provided in the form of component replacement schedule. Category finding damage (FF) recommended replacement components if the level of damage exceeds tolerable limits. Failure of components that include safety problem 13:33%, Outage System 80.00%, 6.67% Economic System. Of the total minimum downtime obtained Screw interval of 30 days, the crosshead link 11 days, Seal 13-day, 12-day screening. Downtime Screw impairment 37.21%, 41.15% crosshead link, Seal 24.56%, and 29.32% Screening

Development of a Reliable Vibration Based Health Indicator for Monitoring the Lubricating Condition of the Toggle Clamping System of a Plastic Injection Molding Machine

Plastic injection molding has become one of the most widely used polymer processing methods due to its ability to viably produce large volumes of complex parts in a short time frame. Most of the plastic injection molding machines currently used in industry possess a toggle clamping mechanism that undergoes a repeated clamping and unclamping cycle during operation. This toggle must therefore be properly lubricated to avoid catastrophic failure and eventual machine downtime. To overcome this limitation, the industry currently relies on the experience of a skilled operator, paired with a fixed empirical value, to determine the timing for re-lubrication. This method often leads to the machine operator either wasting lubricant by over-lubricating the toggle, or damaging the toggle by failing to re-lubricate when needed. Herein, we explore the use of vibration analysis to perform real-time condition monitoring of the lubrication condition of the toggle clamping system. In this study, our novel structural response analysis out performed both traditional time domain and frequency domain analyses in isolating the vibrational signatures indicative of lubricant degradation. Additionally, this study confirms that the vibration generated during the unclamping period of the toggle, proved to contain more valuable information relevant to the instantaneous lubricant quality than provided by its corresponding clamping period.

Optimization of the sheet metal base of a toggle clamp using finite element method

Optimization relates to the ultimate yield strength and the maximum stress incident on the current model under critical working conditions and finds through iterative processing a way to compensate for the strength requirement without going beyond the desired mass limits. In this paper, the horizontal sheet metal base of a horizontal toggle clamp is optimised for mass reduction using the finite element analysis in the computer aided design software. The sheet metal base material is the ANSI32 Steel. In the design software, it is designed with the thickness of 7 mm and it is intended to support a workload of up to 750 N. The constraints were a fixed point added at all the holes and at the bottom surface of the sheet metal base. A number of iterations were made for the 750N loading force across the base plate to run the simulation. For optimization, the aim was to minimize the mass of the base plate. The design parameters were Von Mises, factor of safety and displacement. The variables were the slots’ width and material thickness along the mid-surface of the sheet metal. The mass was reduced by more than thirty per cent overall.

Design of assembly tools at woodworking and upholstery workstations with PUGH’s Method to improve productivity

This study is a research on manufacturing processes field, especially in the assembly process with a single workstation. This research was conducted on the implementation of manufacturing process of making lecture chairs at the Industrial Engineering Department at Sebelas Maret University. In this research, an assembly tool was designed to solve the problem of high time needed to complete the assembly process of the backrest and cushion seat components and work stations that are not ergonomic. The assembly tool design stages are based on a structured approach of Ulrich and Eppinger (2015) so that it’s good to develop new products and concept selection using the PUGH method to find out the concepts with the highest ranking and best fit the design criteria. This research involved 3 stakeholders, namely operator, lecturer, and assistant. The alternative concept chosen using components are pull-push toggle clamp, gas spring, M6 bolt, multiplex, cam buckle tie down, self-aligning ball bearings, aluminum extrusion 3030. Data on work productivity were tested with Paired T-Test at a significance level of 5 percent. The results showed that by using an ergonomic assembly tool design on woodworking and upholstery workstations, assembly cycle time increased significantly by 63.78 percent.

Experimental tolerance design of a six-bar toggle-linkage mechanism using near-singularity characteristics

Tolerance analysis is very important for the mass production of mechanism parts to guarantee satisfactory performance at a low production cost. The tolerance analysis of linkage mechanisms is important because linkage mechanisms are very sensitive to tolerance owing to many shaft–hole connections. Typically, tolerance is determined by intuition and experiences, but it can lead to low performance or high production cost. In particular, the tolerance of a linkage has a significant effect on near-singularity operation as even a very small dimension difference can change the performance dramatically. In this paper, we present an experimental tolerance design of a six-bar toggle-linkage mechanism for clamping application. The tolerance design is very important to the six-bar toggle-linkage mechanism as the clamping operation is performed with a near-singularity configuration. Based on a design of experiment, the tolerances are determined by optimal criteria with performance and cost deviations. We determine the positions with high tolerance and low tolerance empirically. The final tolerances can be used for mass production of the toggle clamping device.

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.

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.

A Double-Toggle Clamping Unit of Injection Molding Machine

The clamping mechanism is one of the important components of injection molding machine. The double-toggle clamping unit is applied in clamping mechanism widely. But, the existing double-toggle clamping unit is connected by cross head driven clamping mold oil cylinder. In the process of movement, especially in the open limit position or a front connecting rod close to the vertical position, the wear is very serious as it may easily cause fracture of tail platen. The paper reviews various patents of clamping unit of injection molding machine through adopting new structures in recent years. The new structure of the double-toggle clamping is presented in this paper. The new structure provided with four pull rod extending connecting lugs. Each connecting ear is provided with corresponding pull rod passes through the guide hole. The cross head can be in sliding the sleeve in the four pull rod. Compared with the traditional toggle clamping, the motion of mold platen is stable and the fracture phenomenon of tail platen can be solved. The tail platen manufacturability and reliability is improved reducing the manufacturing cost due to saving “A” frame of tail platen. Keywords: Clamping mechanism, cross head, double-toggle, injection molding machine, optimization design.

Multi-Objective Optimization Design for Double Toggle Clamping Unit of Injection Molding Machine

Clamping unit is an important component of injection molding machine. The clamping force and the clamping speed of clamping unit not only effect on the quality of molding products, but also determine the cyclic number. The large force amplification and large stroke ratio can reduce energy consumption and improve the productive efficiency. In this article, force amplification ratio and stroke ratio were used as the optimization goals. Non-dominated sorting genetic algorithm was used as the optimization method. The optimization result was better than the original design. So this article provides a reference for the same or similar product’s optimization.

Research on the Key Technologies for New Large Dual-Platen High-Precision Clamping System

High- precision and large scale are the developing trend for injection molding machine clamping system .This paper compared the characteristics of three-platen toggle and dual-platen hydraulic clamping system. The key impact factors that effecting plastic parts` precision from clamping system were discussed systematically first time. Based on these analyses, a new clamping system has been proposed and manufactured to improve the plastics parts` precision, including three new technologies: new type dual-platen structure, parallelism adaptive correction technology and numerical controlled hydraulic servo system technology. It has been applied in practical machine successfully, and experiment result proves that it is effective enough to satisfying the high-precision molding of large plastics parts.

Experimental Study on Mold Separations of Plastic Injection Molding Machines with Different Clamping Units

The plastic injection molding is widely used for the manufacturing of complicated-shaped and high value-added products. The plastic injection molding machine is the most important equipment for the industry. This paper focuses on the mold separation (MS) of the injection molding machines. The characteristics of the MS of injection molding machine with different clamping units are systemically analyzed, the five-hinge joint-double toggle clamping unit and the direct hydraulic pressure clamping unit included. The study points out there are several typical differences between the different clamping units. Meanwhile, it shows there is a linear relation between the MS value and the product weight, and explains why the MS signal can be used to control the injection molding process.

Ultrasonic Leak Test for Automotive Brake Caliper

Leak path defects in brake caliper castings were observed and an efficient method of detecting them was needed. The standard detection technique used a differential decay method at pressures up to 1000 psi but this technique could not detect all of the leak path defects. The only known method that could detect all of the leak path defects was a technique that used brake fluid, and required pressures up to 3,000 psi. Because a fluid medium used to conduct this test, regulations precluded the calipers from being used on a vehicle after the inspection process. This was the motivation for a Capstone Project in the Mechanical Engineering Technology Program at Central Washington University. For safety and economic reasons, a nondestructive test which utilized acoustics was chosen. It was decided that the main focus for this project would be the design of the fixture. The prototype fixture was designed to utilize a toggle clamp and a backing plate (manifold) with O-rings. The clamping system was produced at INTERMET Corporation. After the fixture was completed it was sent to Central Washington University. To verify predictions, strain gauges were used at different parts of the system during normal use. Then the placement of the acoustic listener was determined, completing the test fixture. In order to obtain a good seal (O-ring to cavity lip) the fixture required deflections less then .0045” (as determined by tolerance stacking and O-ring deformation requirements). A magnetic pin gauge was used to measure this displacement as it the fixture was pressurized to 82psi (available shop pressure). To demonstrate the safety of the device, a strain gauge was mounted on the backing plate to measure the force being counteracted by the toggle clamp. The maximum stress on the backing plate was approximately 10% of the material's yield strength (~ 36 ksi for A36 steel); producing a safety factor of about 10. No more than 3750 psi was measured. The maximum strain of the backing plate was 0.003 in/in. Upon completion, the fixture was sent back to INTERMET Corporation where a production model was designed and implemented.

Analysis of premature failure of a tie bar in an injection molding machine

Premature failure of a tie bar made of AISI 4140 steel in a 150 tonne plastic injection-molding machine has been analyzed. Although the nominal tensile stress acting on the tie bars (95.5 MPa) is far lower than the yield strength of this material (750–900 MPa), the tie bars are subjected to a pulsating cyclic loading during the plastic molding process. The failure was found to occur at the root of the first thread by transverse fatigue fracture induced by a pulsating tensile stress with multiple points of high stress concentration. The high stress concentrations appear to have been introduced by a combination of improper molding parameters resulting in uneven tensions in the four tie bars and aggravated by the presence of some material defects. The material defects observed are inclusions, presence of some retained austenite and fine cracks. A hydraulic clamping mechanism rather than a toggle clamp mechanism for the mould will minimize the cyclic strain on the tie rods.

The Kinematic Synthesis of Toggle Clamps

The toggle clamp is one of the most common forms of clamps used throughout industry. They are commercially available in different types and models satisfying almost all ordinary fixture clamping requirements. Based on the theorem of implicit function system existence and the concept of solution plane, computers have been employed to generate planar four-bar mechanisms for three position function generation problem at the toggle positions. A quadratic equation which defines the locus can be plotted in the plane of solutions which have toggle at first, second, or third positions. Additionally this approach offers control over the mechanical advantage at clamping position, and defect free solutions. A vertical acting toggle clamp has been worked for illustrative purposes. This methodology has also been applied to generate slider-crank at toggle position for push-pull type toggle clamps.

Device to prepare extruded nuclei and chromosome squashes.

A horizontal toggle clamp mounted on a rigid base plate makes nuclear extrusion and polytene chromosome squashing simple and reproducible. The base plate has a stage with shallow flat grooves to align the tissue sample directly below the clamp's swivel foot and hold the microscope slide in place during squashing. Appropriate pressure to obtain either extruded nuclei or squash preparations of polytene chromosomes is established empirically by adjusting the clamp's spindle assembly up or down.

Tools for the Workshop

The advantages derived from the utilization of toggle‐type clamping in, the build‐up of jigs, tooling and fixtures can perhaps best be described by segregating them into their individual application to specific types of tools for various jobs. These advantages are dealt with below under three sub‐headings. There are, however, many obvious general benefits in toggle clamping as compared with the stereotyped swing latch or screw clamping methods previously employed. These are briefly: