Počítačová podpora řízení jakosti ve slévárně přesných ocelových odlitků s cílem výroby bez vad

Abstract

For the past 50 years, investment casting or near net shape technology has become extended technology complying with the customers´ requirements regarding casts and this, from the shape and dimensional precision point of view as well as from the material characteristics one. Nowadays, this method is mainly used in machinery, aero industry, armament industry, electronics, medicine and other domains. Art foundry deserves a special note. As the assortment is growing, the requirements regarding dimensional precision as well surface quality and effective production with positive economic impact are also growing. Poor quality management, whose integral part consists in the production flow continuous checking, belongs to the scope of work of all of the company´s employees, who can exert an influence on this field, and this, within any extent. Information concerning the reached poor quality is important, and not for the producer only, but it is also sensitive information especially for the customer. This thesis summarizes the synopsis of a research regarding six practical examples that were resolved in a precision casting foundry by the mean of the investment casting method in order to reduce poor quality production. On the base of the selected cast types´ statistical data processing, it has been possible to evaluate the importance of each individual checkpoint by the mean of the statistical hypothesis testing method. Our attention focused on reducing poor quality production in the phases of the patterns making in the wax workshop and in the ceramic department. Data coming from the technological flow before and after the implementation of changes were compared, and statistically evidential impacts were examined. The aim of that consisted in setting checking in these manners in order to create all the conditions to reduce undesirable scrap and this, already within the course of the production process. The conclusion demonstrates the importance of all of the input factors into the production process without which we cannot have a quality production.