METHOD FOR CALCULATING THE NUMBER OF THROTTLE ELEMENTS OF THE MULTI-TOOTH DORN

The method for calculating the parameters of the cylindrical throttling elements of the tipping teeth of a multi-toothed mandrel has been performed, which makes it possible to provide the required volume and distribution of the working medium flow supplied to the mandrel in the process of processing deep holes of long cylinders and to substantiate the division of the total flow into several different streams that provide throttling of the lubricating-cooling liquid (Coolant) when used in a lubricating and cooling technological environment (SOTS). It is assumed that the processing is carried out on the principles of combining the processes of vortex milling and surface plastic deformation (SPD) by the methods and method of helical interpolation presented in the description of the monograph. The research results based on the developed methodology for calculating the flow rate of the working medium in cylindrical throttling elements allows for further improvement of existing methods for processing deep holes, including improving the quality of high-precision precision pipes.

Evaluation of Grinding of Unfilled and Glass Fiber Reinforced Polyamide 6,6

This paper investigates the grinding process on unreinforced (PA66) and reinforced glass-fiber polyamide 6,6 (PA66 GF30) with Al2O3 and SiC abrasive wheels. Both materials were ground by varying rotations, workpiece infeed speed, depth of cuts for sequential roughing/finishing steps. Dry and liquid coolant conditions were also considered during the grinding process to evaluate the effects on part quality. The surface roughness was used to assess the quality of the final products with several parameter combinations, identifying the induced process trends. The results show that at the end of the finishing step, the surface roughness Rz was lower than 4 μm, attaining the lowest value of 1.34 μm for PA66 specimens. The analysis also suggested the choice of the Al2O3 grinding wheel to reach the lowest Rz values for both materials.

A method for controlling liquid coolant temperature for thermal stabilization of a spacecraft and considerations for design of environmental test chambers using this method

The paper discusses a method for controlling the temperature of a coolant used for spacecraft liquid-based thermal stabilization, which makes it possible to feed to the item that is being thermally stabilized a liquid coolant at an exact preset temperature, with the capability to control the range of deviation from the preset value. The paper describes a liquid-based thermostatting facility for thermal vacuum tests that implements this method. The operational results of such facilities demonstrate the feasibility of using the proposed proven method in the development of environmental test chambers for various purposes. Taking as an example the KI-series Frigodesign® environmental chambers, the paper discusses the key factors driving the cost and power requirements for such chambers, as well as describes some of them that were developed for testing articles at temperatures ranging from –100 to +70 C. Key words: controlling the temperature of the coolant, cooler unit, ground thermostatting of a spacecraft, environmental chambers.

CALCULATION OF PARAMETERS OF CHANNEL THROTTLING OF EXPENSIVE ELEMENTS OF FIRMWARE

The article considers possible options for supplying coolant to the cutting and deforming teeth of multi-pronged firmware for processing deep holes. The advantages and disadvantages of each scheme are indicated. It is noted that when the lubricant-cooling liquid (coolant) is pushed through straight or screw slotted grooves made on the outer surface of the mandrel teeth, "damping pads" are created on the surface to be processed, which improve the mandrel process and reduce wear of the stitches for processing deep holes. For each of the schemes, a method for calculating the coolant flow rate is described, depending on the parameters of the slotted grooves for the coolant flow and the pressure of its supply. The ability to calculate the consumption of coolant through the cutting and deforming teeth of multi-toothed stitches allows you to correctly assign processing modes and, thereby, increase the technical and economic efficiency of mechanical processing of long pipe blanks.