The key to the functioning of enterprises in today's market is the concept of flexibility, which is mainly associated with adapting to very dynamically changing customer requirements. The basis for this approach is, among others, the realisation of serial production, products created for the customer's order in the quantity and time defined in orders. The LEAN Managemnt and LEAN production approach is a solution dedicated to meeting market assumptions. The LEAN concept, which both in the organization of production and management is focused on dynamic response to changes in the environment. The term LEAN represents numerous improvements to the organization, tools and techniques used to reduce and eliminate individual processes (or parts thereof) that are unnecessary activities. The key to analysing entire processes and defining unnecessary activities is thorough observation and selection of dedicated solutions. In the set of LEAN tools, you can find a lot of possibilities, from organization of a workstation itself, to a thorough quantitative analysis of times and process sequences, from simple facilities to complex technological solutions. The article presents the results of the assembly process analysis, indicates the point of product differentiation (marking for the client) and presents the map of organizational and preparatory activities for this process. The presented results are part of the activities within organization of the LEAN approach, currently having priority for the Research entity organisation improvement team.
Today’s market determinants and most importantly, very dynamically changing customer requirements significantly shortened the product life cycle. This situation reflects in companies by common extension of the assortment offered and personalised serial production. The result of a flexible approach to market changes is the implementation of LEAN concept, which, both in terms of management and production aims to develop efficiency within an organisation, which will then enable quick and dynamic response to changes in the environment. The popularity of LEAN concept (in management and production) among managers comes from its universality and a wide range of instruments used to maximise the use of existing potential. The main assumptions of LEAN concept are aimed at the maximum use of an organisation’s resources, defining the activities necessary to execute an order and identifying the areas generating losses and then minimising them and eventually eliminating. LEAN concept is based on flagship-main tools for identification and modernisation of processes, the difficulty in using them results from the need to recognise and select the most effective ones that meet the expectations of a given organisation. The article presents issues related to the first stage of implementing LEAN concept in a company’s structures, i.e. identification of opportunities and selection of appropriate tools.
Grzegorz Filo, Mariusz Domagała, Paweł Lempa, Joanna Fabiś-Domagała, Dominik Kwiatkowski and Hassan Momeni
This article presents results of numerical modelling, simulation and test bench experiments of a hydraulic direct-acting relief valve was used as a safety valve. The analyzed safety valve was placed in a system consisting of a fixed-speed pump, a control valve, a hydraulic cylinder as an actuator and a second pressure valve in the load line used as a payload generator for the cylinder. In the first step mathematical model of the system was formulated in the form of a system of ordinary differential equations. Next, simulation model was created in Matlab/Simulink. Simulations were carried out for different values of the actuator payload. The obtained results include time series of pressure, flow rate and displacement of the actuator piston. In order to confirm simulation results, a test bench was built and series of experiments were carried out. High compliance of simulation and laboratory results was obtained. It was confirmed that the proposed solution with the relief valve used as a safety valve fulfills its task of protecting the hydraulic system from excessive pressure increase.
Mariusz Domagała, Hassan Momeni, Joanna Fabis-Domagała, Mariusz Krawczyk, Grzegorz Filo and Saeed Bikass
Hydraulic valves are widely used in many branches and they are still developed and improved. Due to the problem with verification of flow phenomena which appears during valves operation numerical simulations methods are tools which allows to improved valves design. This paper presents numerical simulation of fluid flow inside flow control valve.
Joanna Fabiś-Domagała, Hassan Momeni, Mariusz Domagała and Grzegorz Filo
Preventive methods are important group of methods used in the process of design and which are known as quality design methods. The aim of these methods is identification of potential failures and cause-and-effect relationships in consistent and systematic way, and then taking appropriate preventive or corrective actions. The well-known examples of preventive methods also used for modelling and analysis of the criticality (risk) factor are FMEA analysis and FTA analysis. A matrix FMEA analysis method has been presented and discussed in the work. The basic assumptions related to this method were characterized and algorithms for each stages of analysis have been presented. It has been presented practical application of FMEA method on example of selected components of hydraulic system.
Joanna Fabis-Domagala, Hassan Momeni, Mariusz Domagala, Grzegorz Filo, Saeed Bikass and Pawel Lempa
Reliability is a key feature in engineering systems and might be improved by using preventive methods, which allows for identification potential failures and establishing cause-and-effect relationships in consistent and systematic way. One of the popular quality improvement method is FMEA (Failure Modes and Effects Analysis). An application of matrix FMEA analysis method on example of flow control valve has been presented and discussed in the work. Presented example shows also a different ways of evaluating failures and theirs influence on analysis results.
Mariusz Domagała, Hassan Momeni, Joanna Fabiś-Domagała, Grzegorz Filo and Paweł Lempa
Hydraulic power systems are widely used in heavy machinery. Safety of such a systems have a major importance due to the fact that any failure may cause environmental contamination or serious injury. One of the component which protects hydraulic drive systems against excessive rising of working pressure is a safety valve which aim is to maintain pressure in the systems below acceptable level. Pressure control valves which plays important role in a hydraulic systems may have very simple or complex structure. Even in case of the simplest structure of such valve modeling is not an easy task. The new quality in designing hydraulic valves bring CFD method and FSI (Fluid Structure Interaction) methods.