A. L. Vorontsov (The Bauman Moscow State Technical University, Moscow), E. O. Reshchikov (The Bauman Moscow State Technical University, Mechanical Engineering Research Institute of the Russian Academy of Sciences, Moscow)

Investigation of internal radial extrusion of a pipe blank.

Part 10. Experimental verification of theoretical formulas during extrusion with hardening of steels 10, 12KH18N9Т and brass L63

The continuation of the experimental verification of theoretical results, begun in previous articles, is outlined. Studies have been carried out on the extrusion of hardening materials: steels 10, 12KH18N9Т and brass L63. The methodology for taking into account hardening in technological calculations is shown in detail. The high accuracy of the obtained calculation formulas and the suitability of the developed methods for the design of industrial processes have been confirmed.
Keywords: die forging; radial extrusion; stress; deformation; pipe blank.

A. I. Kanareykin (Russian State University for Geological Prospecting (MGRI), Moscow)

Investigation of the stress concentration of the cutout in the form of a right angle using the functions of a complex variable

The work is devoted to the measurement of stresses. This article presents an analytical method for studying the stress concentration in the vicinity of the cutout in the form of a right angle. The greatest difficulties in processing and analyzing experimental data arise when studying areas with stress gradients. The approach proposed in this paper to determining the laws of stress measurement in gradient regions is based on solving the plane problem of elasticity theory by methods of complex variable functions.
Keywords: stress; complex variable function; elasticity theory; stress function; cutout in the form of a right angle.

A. I. Kanareykin (Russian State University for Geological Prospecting (MGRI), Moscow)

Non-stationary mode of heat transfer in the rod

The article is devoted to the issues of heat transfer through the rod. It considers a non-stationary process. In this case, the rod is considered homogeneous. In this paper, the solution of the problem is given using the formal Bers apparatus. By separating the variable, a formula is obtained for finding the temperature field of the rod under given initial conditions.
Keywords: rod; heat transfer; thermal conductivity; differential equation; unsteadiness; Bers apparatus.

S. A. Gubar (Pacific State University, Khabarovsk)

Shaping of the transition surface when processing cylindrical wheels with arched teeth

When processing cylindrical wheels with spiral-disc tools, the dimensions of the reproduced theoretical tooth surface are limited by the length of the tooth. Based on ensuring that the transmission width of the toothed crown is sufficient for effective operation, it is necessary to allow the formation of a part of the lateral surface of the tooth at the ends by the transition surface of the vertex edge of the teeth of the tool. The study of the geometric and strength properties of arched teeth requires the development of a tool that allows analyzing the geometry of not only the main theoretical, but also the transition surface of the tooth. The paper solves the problem of deriving analytical ratios that determine the transition surface of an arched tooth during its processing with spiral-disc tools. The problem is solved by the methods of the theory of gearing. The article considers the geometric and kinematic scheme of the formation of the rounding surface of the tool turns, the main stages of obtaining expressions describing the rounding surface, the derivation of relations determining the radius vector of the transition surface on the wheel tooth formed by the rounding surface of the tool. The results obtained make it possible to determine the real boundaries of the reproducible theoretical surface, taking into account trimming, to determine the possibility of sharpening the teeth at the ends of the wheel, as well as to evaluate the bending strength of the teeth.
Keywords: vertex edge; producing surface; envelope; transition matrix; radius vector; transition surface.

I. A. Burlakov, P. A. Polshkov, M. V. Shabolin (JSC United Engine Corporation, Moscow); P. A. Petrov (Moscow Polytechnic University, Moscow)

Bending thin-walled pipes using PLA tools

The results of studying the possibility of using PLA tools for bending thin-walled pipes with a diameter of up to 18 mm are presented, and an analysis of the stress state obtained by modeling the process using the QForm program is given. Taking into account the modeling results, a PLA tool is manufactured and tested, and recommendations for its use are given.
Keywords: pipe blanks; stainless steel; pipe bending; PLA; QForm; tool testing.

N. A. Morgunov, D. A. Smirnov, I. V. Korostelev, M. O. Nosenko (Pacific State University, Khabarovsk)

Experience in designing a hydraulic drive using the example of a monorail cableway switch

The current article discusses the design of a hydraulic cylinder based on SolidWorks software. During the research, a simulation model of a hydraulically driven switch was developed. Based on the requirements for the switch, the principle model of the hydraulic cylinder is selected. For visualization, a three-dimensional model was created, which allows you to calculate the required parameters and monitor the progress of solving the model under study. In the process of calculations, graphs of the dependence of the fluid pressure on the hydraulic cylinder piston on time were obtained, when the parameter of the incoming fluid velocity into the hydraulic cylinder changed. Based on the simulation results, a conclusion was made about the adequacy of using models to assess the characteristics of the designed switch. It is recommended to develop and use such models at the stages of preliminary and technical design.
Keywords: hydraulic cylinder; liquid; physical properties; pointer switch; force, pressure.

Y. N. Loginov (M. N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences;

Ural Federal University named after the first President of Russia B. N. Yeltsin, Yekaterinburg); Y. V. Zamaraeva (M. N. Mikheev Institute of Metal Physics of Ural Branch of Russian Academy of Sciences, Yekaterinburg; Kamensk-Uralsky Metallurgical Works J. S. Co., Kamensk-Uralsky)

The influence of the shape of the ends of the initial billet on the process of stamping a magnesium ball

Simulation of the process of stamping a magnesium ball from a cylindrical billet with flat, conical and spherical ends is carried out. The analysis of the stress–strain state of the metal during stamping shows that the distribution of deformation and the level of its values depend on the shape of the ends of the billet. The assessment of the stress state indicator by the volume of the balls make it possible to identify the danger zone from the position of destruction. It is established that the zones of maximum deformation and the zones of action of a high level of compressive stresses coincide, which means that the threat of destruction of the balls is minimal.
Keywords: forming; magnesium; stresses; deformations; finite element method.  

M. Sh. Gatiev (Ingush State University, Magas)

Development of a coolant to increase the drilling strength of refractory metals

The problem of increasing drilling strength during working with hard metals is studied. By its structure, during processing such metals, both the cutting surfaces and the drills used during operation are quickly deformable. These costs of the process entail additional expenses, wasting time on replacing the material used, which naturally slows down this processing method. The purpose of this work is to develop a coolant that will improve drilling performance and increase the service life of the drill.
Keywords: drilling; deep holes; metals; difficult to machine; operability.