Investigation of the Operational and Technological Reliability of the Small-size Internal Threading Process

The article presents the results of research in the direction of improving technological equipment for internal threading of parts in a flexible automated production. Methods for assessing the operational and technological reliability of a flexible manufacturing module (FMM) of thread processing are considered, which can be used as the basis for the developed method of synthesis of its elements. It is proposed to consider the technological system of the flexible manufacturing module (FMM) of thread processing as a system in which transitions from state to state occur under the action of the simplest flows with parameters of the transition probabilities of a continuous Markov chain. The developed mathematical model describing the state of the FMM taking into account the failures of the functioning of its elements, parametric failures, as well as taking into account the recovery after these types of failures, makes it possible to reflect the influence on the operation of the module of the parameters of the flows of failures and restorations of the tool, machine tool, fixture, loading device. The solution of the obtained systems of equations of final probabilities allows for given (or experimentally obtained) intensities of failure streams (functioning and parametric) for FMM threading to obtain the values of the probability of failure-free operation, as well as the probabilities of finding the system in an inoperative state due to corresponding failures. The measures taken make it possible to solve the synthesis problem at the level of structural and layout optimization, so that at the stage of parametric synthesis to determine the elements that are vulnerable according to the developed criterion, the improvement of which will lead to the creation of the most efficient system.

Algorithm Synthesis of Controlling a Transport Unit of a Coextrusion Flexible Manufacturing Section for Processing Multicomponent Materials

The paper offers a mathematical model of the process of coextrusion flexible manufacturing section functioning. On the basis of dynamic programming method an algorithm of controlling transport unit of coextrusion flexible manufacturing system is developed. The objective of the current research is the development of the mathematical model of the flexible manufacturing complex for processing multicomponent materials functioning process, and construction of the algorithm of controlling a transport unit of a coextrusion flexible manufacturing complex for processing multicomponent materials on this basis. The paper offers the criterion of evaluating the quality of controlling the transport unit. The chosen variant of controlling the transport unit has to meet many requirements. This paper con-siders the issues connected with the search for an optimum algorithm of control-ling a transport unit according to the set criterion. Most works offer analytical models which are based on the assumption of the current processes’ stability. Real manufacturing conditions are characterized by the effect of numerous perturbing factors. Under such conditions the assumption of the current processes’ stability makes the obtained models almost untrue.

DEVELOPMENT OF AN AUTOMATED DESIGN SYSTEM FOR FLEXIBLE AUTOMATED PRODUCTION

Design of flexible manufacturing systems (FMS) of modern multi-level production is usually carried out on the basis of general rationing when using large recommendations. At the same time, the specifics and features of a particular production are not always taken into account. In such a design, the most important is the experience of the designer, which is not always based on modern methods of optimizing project solutions. Therefore, the problem of creating automated design systems in the development of flexible automated productions (FAP), which use cost equipment with numerical control (CNC) is extremely urgent. The development of automated design systems is based on the ideas of a systematic approach that determine different cycles of the process: design - production preparation - production. Information about the projected object is generated in the process of project development by different groups of users: researchers, designers, designers, technologists, production organizers. A multilevel, cyclical design process requires the use of such a volume of information that cannot be processed without the use of modern mathematical methods and calculated equipment. Therefore, it is extremely important to create automated gap design systems, which are marked by greater versatility, efficiency and possibility of development, improvement and adaptation to the conditions of various enterprises. Such requirements served as the basis for the creation of an automated design system , which allows to take into account a huge amount of information in the automatic cycle during the development of the project. The scientific novelty of the work is the development of an integrated automation system for the design of processing technology and the selection of elements of FMS structures. At the same time, information unity with the system of technological training of production at the level of operation of FMS is ensured.

USING THE SLP METHOD IN THE DESIGN OF FLEXIBLE MANUFACTURING CELLS

Flexible manufacturing systems are becoming increasingly important as customers increasingly want customized products. Also, the trend of the product life cycles to become shorter and shorter causes the proliferation of flexible manufacturing systems. Proper layout is key to making the manufacturing system truly flexible. Novel research and this article show how the Systematic Layout Planning method can be applied to the design of flexible manufacturing systems and, going further, how the design process can be supported by manufacturing process simulation.

Enhancing the Lifetime of the Pneumatic Cylinder in Automatic Assembly Line Subjected to Repeated Pressure Loading

This study demonstrates the application of parametric accelerated life testing (ALT) as a procedure to identify design deficiencies and correct them in generating a reliable quantitative (RQ) specification. It includes: (1) a system BX lifetime that X% of a product population fails with a parametric ALT scheme, (2) fatigue design, (3) ALTs with alternations, and (4) judgement as to whether the design(s) secures the desired BX lifetime. A (generalized) life–stress model through the linear transport process and a sample size formulation are suggested. A pneumatic cylinder in a machine tool was used as a case study. The cylinder was failing in a flexible manufacturing system. To reproduce the failure and modify the design, a parametric ALT was performed. At the first ALT, the metal seal made of nickel-iron alloy (36% Ni) partially cracked and chipped and had a crisp metal sound. It was modified by changing the seal from a metal to a polymer (silicone rubber). At the second ALT, the piston seal leaked due to seal hardening and wear. The failure modes of the silicone seal in the laboratory tests were similar to those returned from the field. For the third ALT, the seal material was changed from silicone rubber to (thermoset) polyurethane. There were no concerns during the third ALT and the lifetime of the pneumatic cylinder was shown to have a B1 life of 10 years.

A simulation-based approach to identify bottlenecks in the bearing manufacturing process

Flexible manufacturing processes improve profitability and competitiveness for the company through an efficient process, with quality in a short time, and contribute to achieving low costs. One of the approaches that have been currently developed to improve the flexible manufacturing process is simulation. Simulation models consist of an assertive and powerful tool in strategic planning. It permits a controlled way of the company's reality so that it was possible to study and analyze the organization's current situation under several circumstances without altering the production's physical environment and involving low costs. Accordingly, this study's primary purpose was to develop a simulation model to verify bottlenecks' existence in the bearing manufacturing process. For this, a case study is presented, and it was used modeling/simulation with Arena Software as a research method. The results showed no bottlenecks in the manufacturing process.