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卷 36, 编号 4 (2016)
- 年: 2016
- 文章: 20
- URL: https://journals.rcsi.science/1068-798X/issue/view/13947
Article
Dynamic hardening of structural polyurethanes
摘要
The deformation of an elastic polyurethane rim is investigated experimentally. An empirical formula is derived for the dynamic-toughening coefficient of polyurethane, with allowance for the hardness and load rate.
255-257
Shaping of discrete abrasive segments for plane face grinding
摘要
The shaping of discrete abrasive segments for plane face grinding is considered, along with the necessary tools. Measures significantly reducing the costs on switching to discrete plane face grinding are identified.
258-261
Neural-network simulation of diesel operation under a nonsteady load
摘要
The operation of diesel engines with nonsteady loads is considered. Numerical experiments are based on a model, a neural network, and test-bench data.
262-265
Nonuniform delivery rates from multicylinder pumps
摘要
Analysis of the nonuniform delivery rate from a multicylinder pump indicates its dependence on the working volume of the pump chamber, the diameter of the pistons, and their angular configurations with odd and even numbers of pistons.
266-269
Dynamics of an indirect hydraulic pressure regulator with an elastic element
摘要
The dynamics of an indirect pressure regulator in which the primary valve is a toroidal elastic element is considered. A mathematical model of its transfer function is derived.
270-272
Contact rigidity of parts with similar hardness
摘要
A method is proposed for determining the decrease in the distance between nominally flat rough surfaces with similar hardness in the plastic deformation of the surface microprojections.
273-276
Photometric determination of the dimensions of a standard object with basing errors
摘要
Contactless surface measurement using plane-parallel length gages is considered. A method is proposed for determining the size of a standard object with basing errors relative to the camera.
277-278
Friction in the annular gaps between the control rods and housing of the BREST reactor
摘要
Friction and wear between the casing of the control rod and the reactor housing with cyclic rod motion and circulation of high-temperature molten lead in the annular gap.
279-284
Frictional basalt-reinforced polymers based on polytetrafluoroethylene
摘要
The properties of basalt-reinforced polymers based on polytetrafluoroethylene are investigated as a function of the concentration of basalt fibers and their activation conditions. A high-speed planetary mill may effectively be used for the activation of the basalt fibers.
285-288
Structural failure at low temperatures and stability diagnostics
摘要
The influence of impurities on the cold brittleness of materials is studied. A neural network is trained to model fatigue and brittle failure of samples. The neural network generates numerical sequences that evolve analogously to the fractal characteristics of acoustic emission studied in fatigue tests with various loads.
289-293
Determining the stability regions in end milling
摘要
The stability regions of self-oscillation in the end milling of a rigidly fixed workpiece according to analytical calculations and simulation are compared. Possible explanations for the discrepancies are reported.
294-299
CAD/CAE modeling of Maltese cross mechanisms in machine tools
摘要
New software for calculating the parameters of Maltese cross mechanisms in machine tools has been developed at Stankin Moscow State Technical University. This software permits the construction of three-dimensional models in CAD systems and hence significantly improves the automated design of Maltese cross mechanisms.
300-302
CAD/CAE systems in the design of numerically controlled multipurpose machine tools
摘要
A method of generating a finite-element model for a multipurpose machine tool on the basis of CAD/CAE systems is outlined. The model permits static analysis of the machine tool at the preliminary design stage. The configuration of the machine tool affects its main characteristics: the static and dynamic elastic deformation, the thermal deformation, the pressure distribution, and the wear in mobile joints.
303-308
Nondestructive assessment of the cutting properties of wheels with a single-layer diamond–galvanic coating
摘要
A new approach to determining the cutting properties of a diamond tool with a single-layer diamond–galvanic coating is proposed. The method is based on determining the concentration of diamond grains in the working layer of the tool.
309-311
Measuring instruments for shafts
摘要
Instruments for shaft measurement are considered for the example of Mahr (Germany) products. The instruments and measuring methods are described and their benefits are itemized.
312-317
Indicators for linear measurements
摘要
Indicators are mechanical or electronic measuring heads showing the readings by means of an arrow and a scale or a digital display. While mechanical indicators with an arrow and a scale have long been in use, electronic indicators with a digital display are more recent inventions, which offer high performance and the ability to measure absolute values. Therefore, it is expedient to clarify the benefits and optimal applications of mechanical or electronic indicators in manufacturing today.
318-320
Influence of rigid and frictional kinematic linkages in tool–workpiece contact on the uniformity of tool wear
摘要
The motion of the machined part over the tool’s working surface is considered in raster finishing with frictional kinematic linkage. The relative trajectories of the part and tool are analyzed. In forward movement of the lap, rigid kinematic linkage in the part–tool contact is recommended.
321-323
Influence of tool wear on the heat-flux distribution and temperature at the contact surfaces in the end milling of OT4 titanium alloy
摘要
The influence of tooth wear at the flank surface on the heat-flux density due to plastic deformation, chip friction at the tooth’s rake surface, and friction of the flank surface at the workpiece in end milling is considered. The dependence of the cutting temperature on the tool wear is obtained. The thermal field in the tool is calculated.
324-327
Improving the precision of mechatronic robot drives
摘要
A new structure is proposed for precision servo drives in industrial robots, and its properties are analyzed. The servo drive is a mechatronic device containing high-precision sensors, microcontrollers, and electrical and mechanical components. The theoretical results that underlie the design of a precision drive containing an elastic mechanical transmission with free play are outlined. Computer simulation indicates high precision of the drive and its suitability for use in industrial robots.
328-334
Producing thin-walled BrA9 bronze components by selective laser melting
摘要
The selective laser melting of the fine structure of BrA9 aluminum bronze is studied. The optimal parameters for precise reproduction of the geometry of CAD models are presented.
335-338