ANALYSIS OF THE CHANGE IN ROUGHNESS ON A FACE-MILLED SURFACE MEASURED EVERY 45° DIRECTION TO THE FEED

In this article, we analyze the difference (inhomogeneity) of the roughness values measured on a nonalloy carbon steel surface milled with a parallelogram-shaped (κr = 90°) insert as a function of the the tool movement direction and the relative position of the examining points on the workpiece surface. The characteristic distribution of roughness and the magnitude of the deviations were examined by measuring at selected points along several planes on a surface characterized by the movement conditions of the workpiece and the symmetrically arranged tool perpendicular to the machined surface, which formed double milling marks. The selected points mark the lines with specified inclinations with respect to the feed direction, and their measured values were compared. In these directions, the magnitude of the difference in roughness measures was obtained.

RESEARCH OF THE CUTTING MECHANISM AT ELECTRICAL DISCHARGE GRINDING

The paper presents the results of a study of the cutting mechanism during electrical discharge grinding of hard alloys. The cutting mechanism during electrical discharge grinding was studied using mathematical modeling. By means of geometric modeling, a method of grinding cup wear was developed. The functional dependence of the diamonds use factor in the Kw wheel on the technological parameters of processing, wear and tool characteristics were determined. Analysis of the results of the study shows that an increase in efficiency at electrical discharge grinding can be achieved by reducing the wear of S, and by corresponding variation in the concentration of diamonds and technological modes of processing.

PROCESSING OF HARDENED CYLINDRICAL GEAR WHEELS OF THE CUTTING GEARBOX OF THE COMBINE UKD 200-500

The article discusses the latest developments of unique technological methods of gear milling of cylindrical gears for preliminary blade gear processing of hardened cylindrical gears of the cutting reducer of the UKD200-500 coal mining harvester for the final gear grinding of gear teeth with modulus m = 16 mm, with hardness HRC 56 ... 62. The peculiarity of the design of special hob cutters is that a circle passing through the lower boundary points of the involute is used as the palloid of the machine gearing of the tool and part. Pre-cutting the teeth of hardened wheels with carbide milling cutters allows you to remove the main allowance for the final gear grinding.

IMPROVING GRINDING OF GEAR WHEELS APPLIED IN GEARBOXES OF POWER ENGINEERING

Development of modem power engineering follows the line of continuous increase in speed, coefficient of corrosive action and capacity of units. Gears and reducers are responsible parts of modem machinery and occupy an important place in the domestic power engineering construction. Durability and wear resistance of gears, apart from the design factors, also depends on the technological methods of treatment. The final stage of production of such wheels is the operation of gear grinding. In the process of gear grinding in a thin surface ball there are complex thermomechanical processes. As a result of short-time heating to high temperatures, structural transformations, burns, and in some cases even micro- and macro-thicknesses occur in such a surface bail. In addition, there are cases of making tooth wheels with adjacent defects grinding (for example, the appearance of the surface of the ball teeth of large tensioning forces), which reduces the life of the work, and in some cases causes a breakdown of the teeth in operating conditions. Development of effective measures to ensure the quality of the surface of the ball on the operation of grinding baggage in part depends on the possibility of predicting (or calculation) of temperatures and residual loads on the depth of the cemented teeth ball. The method of calculation of internal surplus Toads occurring during grinding of wheels with cemented steels is suggested. On the basis of the performed calculations and experiments the ways to improve the quality of production of working surfaces of gears, which are used in the wits of thermal and nuclear power plants are suggested and grounded.

ANALYSIS OF TENSENESS AND DURABILITY OF THE MAIN PARTS FOR THE CUTTING PART OF UKD 200-500 COAL SHEARER

JSC "Kharkiv Machine-Building Plant "Svitlo Shahtarja" has created and introduced into serial production a new generation UKD200-500 coal shearer. The most loaded element of the shearer is its cutting part. It is a three-stage reducer with an electric motor. Calculations for the strength and durability of gearing, shafts, bearings, spline, pinned and hinge joints have been carried out. The modeling of the stress-strain state for the main parts and assemblies by the finite element method has also been carried out. Calculations have shown that the strength and durability of all parts is ensured. Consequently, the required durability of 15000 hours and the average resource before major overhaul are not less than 800...1000 thousand tons are provided.

RESULTS OF INDUSTRIAL TESTING OF CARBIDE CUTTING TOOLS BY PULSED MAGNETIC FIELD TREATMENT AND THE EFFECT ON THE INCREASE OF THE CUTTING PROCESS EFFICIENCY

The task of increasing the efficiency of machining parts on heavy machines was determined, scientifically substantiated and solved by hardening a carbide tool the pulsed magnetic field processing (PMFP). The efficiency of machining of parts is understood as an increase in its productivity, a reduction in the cost and costs of tool materials, and an increase in instrument reliability. The working conditions of cutting tools at heavy engineering enterprises are analyzed. The wear resistance of carbide cutting tools, which have been strengthened by the PMFP, was investigated using forced test methods and modeling of the cutting process. The mechanism of changing the properties of a hard alloy under the action of a pulsed magnetic field is established. The main factors affecting the change in the wear resistance of a hard alloy under the action of a pulsed magnetic field are identified. The effect of pulsed magnetic field processing on the performance of carbide cutting tools under production conditions is investigated. The effect of hardening on productivity, cost of operation and instrumental costs is established. The interrelation of the parameters of the PMFP, the parameters of the process of machining parts and production efficiency is investigated. A statistical model has been developed that allows determining the productivity of mechanical processing depending on the properties of the tool material and the processing parameters of a pulsed magnetic field.

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.

DIGITAL TWIN TECHNOLOGY IN LOGISTICS LITERATURE REVIEW

The digital twin has been released in a number of industries that include logistics as well, with the creation of new research areas. To find the research area, a complex literature analysis is required. At present, publications in scientific journals and publications on the Internet are more important than print-based literature. Because of this, you can get huge results with a single search. It is important that you can analyze these databases well. One method of this analysis is systematic literature review.

FINISH MACHINING OF THE CUTTING INSERTS FROM CUBIC BORINE NITRIDE BL GROUP COMPOSITE

Finishing methods of machining of superhard composite’s working elements based on cubic boron nitride BL group are considered. The results of the microgeometry formation research of the cutting inserts’ surfaces during machining by free powders of synthetic diamond, grinding wheels and a method of vibro-magnetic-abrasive machining (VMAM) are presented. It is shown that during VMAM the friction between the inserts’ surfaces and the abrasive particles result in microremoval of the material, which reduces the roughness of the cutting inserts’ surfaces. It is established that additional fine grinding with 14/10 mkm synthetic diamond powder provides the absence of microgeometry defects of the cutting inserts’ surfaces left by pre-machining. The result of high-quality rounding of cutting edges and the formation of surfaces of cutting inserts with less roughness is an increase in strength and wear resistance of metal-cutting tools in high-speed machining under conditions of significant loads.

INTERACTION OF THE ABRASIVE MEDIUM WITH THE TREATED SURFACE AND THE PROCESS OF METAL REMOVAL DURING VIBRATION TREATMENT IN THE PRESENCE OF A CHEMICALLY ACTIVE SOLUTION

Interaction of working medium granules with the processed surface of the part is considered. It is noted that the processing methods are characterized by the dynamic interaction of the abrasive medium with the processed surface. It is indicated that during vibration treatment there is an impact contact of the abrasive granule with the surface of the part, which leads to the formation of characteristic traces during the formation of the surface relief. The types of impact of abrasive grains of working medium granules on the surface of the processed part are identified. It is indicated that the effect of abrasive grains depends on the geometric parameters of the tops of the grains and the working contour of the granule as a whole. The alternation of the operation of abrasive grains in the connection with the nature of the motion of the granule over the surface of the part is shown. The interaction of surfaces of bodies during vibration treatment is considered. The distinctive features of the vibration treatment method from other analogs are indicated. The conditions for the formation of the surface layer of the part during vibration processing are given. The analysis of the mechanical-physicochemical model of the micro-cutting process in the presence of a chemically active solution is carried out and a comparison of the intensity of technologies for vibration treatment of steel parts is given.