OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 5 No. 3 2023 patterns are considered: using standard factory technology and using the proposed integrated processing. An analysis of the presented data will confirm the effectiveness of the introduction of the developed hybrid metalworking equipment and demonstrate the advantages that it can bring compared to traditional processing methods. According to the factory manufacturing process of the plug, after pre-machining, the operation “Surface HFC hardening” is performed. In this operation, it is necessary to take into account the technological depth of hardening, taking into account the subsequent finish machining (grinding). The technological depth of hardening in this case should be AT = 0.84 + 0.1 mm [97, 98]. However, it should be noted that according to the data of the enterprise, approximately 7 % of manufactured parts are subject to rejection due to the presence of burns and microcracks on the surface, which are formed during the “grinding” operation. To achieve the specified thickness of the hardened layer using a generator with a frequency of 440 kHz, it is required to implement a surface heating scheme. In such a scheme, the specific power and speed of the heating source will be lower compared to the volumetric scheme. The active wire of the inductor has a width RS = 4 mm and its length b = 15 mm, which corresponds to the specific power qS = 1.2∙10 7 W/m2 and the speed VS = 2 mm/s. To harden the part, it is necessary to process two sections with a total length of 300×2 = 600 mm. Both sections are processed for two longitudinal movements of the loop inductor relative to the workpiece. The total length of the tool stroke (displacement along the X axis), taking into account the entry and exit of the inductor with a continuous-sequential heating scheme, is l = (300 + 8 + 4)2 = 624 mm. With these parameters, the basic time is Tb = l/Vd = 312 s. In accordance with the general engineering standards for heat treatment at HFC installations, the auxiliary time for basing a part of the plane type is Tnp. = 15 s. Thus, the single-piece productivity is equal to 1 1 1 0.003 312 15 sp b np P s T T - = = = + + and energy demands are equal to 7 1.2 10 0.015 0.004 0.624 0.062 0.002 i s d q b R l E kW h V ⋅ ⋅ ⋅ ⋅ = = ≈ ⋅ . The final stage of the technological process of manufacturing a part using hybrid metal-working equipment was carried out on a modernized multi-purpose machining center MC032.06 and consisted of three transitions: preliminary (rough) and semi-finish machining, surface HFC hardening, and fine milling. The machine tool system was equipped with an additional power source, which was a microwave thyristor-type generator SHF-10 with an operating current frequency of 440 kHz. To measure and control the operating frequency of the induction heater, a Hantek DSO 1000S Series digital oscilloscope was used. Based on the dimensions of the part 25×160×300 mm made of steel U10A, a following blank was taken: a sheet 30×170×310 mm. For referencing in the machine, a pair of special self-centering vice chuck with a jaw section of 40×100 mm was used. The first stage of manufacturing was the shaping of the connecting base of the punch, which included roughing and finishing with face and end mills with carbide indexable insert. Based on the technical characteristics of the machine and the material being processed, a tool was selected and cutting conditions were calculated. For roughing, an IE21-90.11A16.040.05 end mill with a diameter of 40 mm was used with APKT113508R-GL IA6330 inserts designed for milling carbon and stainless steel, and hard materials. Cutting modes: VC = 200 m/min; ap = 5 mm; ae = 30 mm; Vf = 800 mm/min. The same tool was used for finishing the plane in the following modes: VC = 350 m/min; ap = 0.15 mm; ae = 30 mm; Vf = 500 mm/min. To form the connecting grooves, a solid carbide cutter with a diameter of 4 mm with an edge radius of 0.2 mm and a ball cutter with a diameter of 2 mm were used, in the following modes: VC = 50 m/min; ap = 0.5 mm; ae = 4 mm; Vf = 500 mm/min. During the hardening process, a loop-type inductor equipped with N87 ferrite was used (fig. 2) [7, 14, 17, 21, 47, 61, 71–73, 75, 82–83, 87]. The inductor is installed in an adapter mandrel made of ZX-324 GF30 PEEK glass-filled plastic, capable of operating at elevated temperatures and securely fixed in a tool chuck with a collet (fig. 6). The studies were carried out using intensive water circulation cooling of the inductor (fig. 2).
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