MM SCIENCE JOURNAL I 2021 I OCTOBER 4803 RATIONALIZATION OF PRODUCTION OF SHAPED INSERTS FOR ROTOR CASTING PAVEL DOSTAL, MAREK SADILEK Faculty of Mechanical Engineering, Department of machining, assembly and engineering metrology VSB-TU Ostrava, Czech republic DOI: 10.17973/MMSJ.2021_10_2021088 Email: dostal.pa@email.cz The article deals with the rationalization of the production of shaped inserts for casting rotors. The theoretical part describes the characteristics of shaped inserts for rotor casting, die casting technology, analysis of the existing technology of production of shaped inserts. The main part of the article is focused on the proposed technological process of production, comparison of existing and proposed process. The article concludes with a technical and economic benefit of the proposed solution and evaluation of the work. Rationalization of production has its justification in the development of the company and thus improve competitiveness in the market. These interventions in production offer the possibility of using new technologies that are beneficial both from an economic point of view and to improve working conditions. The article focuses on the description of the existing technology, its evaluation and subsequent processing of a new technological process. KEYWORDS Rationalization, die casting, shaped inserts, casting, milling 1 INTRODUCTION Shaped inserts for rotor casting (hereinafter only inserts) are always produced in two versions, one front and one rear. They are used for axial heights numbered 100, 112, 132 and 160. After production in the tool shop, the insert is put into die- casting operation. Here it is inserted into a device for high- pressure aluminum casting. Multiple inserts can be stacked in the die at the same time according to the axial height. As already mentioned, the insert consists of two parts. We can divide them into fixed and movable. The fixed part is clamped on the table and there may be an inlet. On the contrary, the movable part is clamped on the mold carrier, where the mechanism for releasing the casting is located. 2 THE PROCESS OF MANUFACTURING SHAPED INSERTS The process can be divided into several phases. The customer requires certain term, price and technical requirements that must be met or agreed upon. These requirements result in a drawing or 3D model. This documentation contains dimensions, tolerances and acceptance conditions. If the castings are machined, not only is the documentation for the casting sufficient, but must also be supplied for the finished product. In the next step we can include the design of molds and tools for processing, material security, project plan, etc. An integral part is the processing of clamps, separate construction of the insert, construction of inspection jigs and tools. Emphasis should be placed on the production of the insert in such a quality that it does not have to be tested. The production of injection molds is a highly valued branch of today's engineering. A large number of molds are produced from tool steels by machining or electroerosive machining, but molds are also being produced by other technologies such as electroforming. Probably the largest share of all technologies is machining by milling. Constant pressure to reduce machine times and production costs leads to the development of milling methods and the use of eg high-speed machining (HSC), machining of very hard materials or dry machining, as well as the use of modern 5-axis machining centers. Current trends in machining lead to increased cutting speeds, removal of larger volumes of material, often without the presence of any process fluid. In addition to a machine tool capable of achieving the required cutting speed, rigidity and secure clamping, it is necessary have a specially designed tool. The mold test is performed in order to capture the parameters of casting from a technological point of view, as well as the dimensions, parameters of castings and, last but not least, to check the alloy used. During the process, it is important to optimize the insert according to the design agreed with the designer, tool shop and foundry. Data processing for zero series. The last step is the second test or production of the zero series. We verify inspection and production operations here. We emphasize the preparation of samples with a protocol, which is sent to the customer together with documents for serial production. [Grov 2005] 3 PROPERTIES OF SHAPED INSERTS FOR CASTING ROTORS The material for the production of all types of shaped inserts was chosen according to the standard, CSN 19 552.3. The standard states that it is a medium alloy chromium- molybdenum tool steel. Requirements for the mold material used, good machinability, good hardenability, high yield strength, good thermal conductivity, low thermal expansion, adhesion resistance, dimensional stability during heat treatment. [Dostal 2012] Figure 1. Solved shaped inserts [Dostal 2012] CSN W.-Nr. DIN POLDI AISI BS JIS 19 552 1.2343 x38Cr MoV5 1 TLH H1 BH1 SKD 6 Quality - CSN C Si Mn Cr Mo V 19 552 0,4% 1% 0,4% 5,3% 1,3% 0,4% Hardening temperature Soft annealing Hardness after annealing - - - - 1020- 1050°C 780- 820°C 200HB - - - - Table 1. Material for the production of shaped inserts [Lentus 2007]