卷 37, 编号 3 (2017)
- 年: 2017
- 文章: 22
- URL: https://journals.rcsi.science/1068-798X/issue/view/14019
Article
Evolution of methods of assessing the accuracy of metal-cutting machines
摘要
The evolution of concepts of accuracy and attainable machining accuracy are considered. The physical aspects of accuracy are discussed. The changes in the level of precision since 1800 are outlined, with predictions of what is attainable in the future. The energy barrier to accuracy is analyzed for various cutting technologies.
171-179
Electrical roasting systems with vibrational batch supply
摘要
The operational principle of electrofurnaces used to roast vermiculite, sungulite–vermiculite conglomerates, and other minerals is blocking their further development. An alternative design is proposed, with vibrational batch supply. Higher-energy furnaces may be created on that basis.
180-184
Automatic control of a stepless mechanical transmission with an internal force function
摘要
Stepless mechanical transmissions with vibrational motion of the internal elements are considered. In particular, attention focuses on their regulation. Basic principles are outlined for automatic control of a transmission with an internal force function depending on the vibrational amplitude of the internal elements.
185-188
Thermal model of spindles on rolling bearings
摘要
By means of the proposed thermal model and corresponding software, the thermal characteristics of high-precision spindles may be quickly assessed in the initial stages of design.
189-194
Hybrid laminated materials with slow fatigue-crack development
摘要
The use of light aluminum–lithium alloys with high elastic moduli in hybrid laminated materials for the production of skin panels in airplane wings is considered.
195-199
Influence of the microprojection geometry on the elastic contact of surfaces with regular microrelief
摘要
The influence of surface microprojections—their shape and additional harmonics—on the elastic contact of a flat surface and a surface with regular microrelief is considered on the basis of the elastic contact of a half-plane and an undulatory surface. It is shown that the contact-pressure curve depends on the surface gradient of the microprojection and the mutual influence of adjacent microprojections.
200-205
Self-lubricating bearings based on compound epoxy fluoroplastics
摘要
The use of self-lubricating antifrictional materials based on compound epoxy fluoroplastics is considered. Their operation in different frictional conditions is analyzed.
206-210
Improving the life of artillery systems
摘要
The factors that affect the wear and durability of artillery systems are considered. The dependence of the barrel wear on the number of shots fired is determined experimentally. The use of wear-free technology in barrel manufacture reduces the wear by an order of magnitude and thus extends barrel life.
211-217
Molybdenum-coated blanks for reliable frictional disks in oil-filled transmissions
摘要
Molybdenum-coated blanks for frictional disks in vehicle transmissions permit improvement in their performance. The coating is applied by plasma spraying.
218-223
Protection of standard network protocols of automated production control systems
摘要
Individual aspects of information security when using automated control systems in production are considered. The network-interaction protocols and the characteristics of possible phishing attacks on the control-system components are described. The use of firewalls and systems for intrusion detection is proposed.
224-232
Selection of metal-cutting machines in operational design by means of PLM systems
摘要
A method is proposed for the selection of metal-cutting machines in the design of technological operations using Teamcenter and UNIGRAPHICS NX software.
233-237
Influence of the positional error of the axial drive module on the machining precision in a lathe
摘要
A method is proposed for assessing the influence of the positional error of the axial drive module on the machining precision in a lathe.
238-243
Abrasive tools for hole machining in robotic systems
摘要
The operation of a single abrasive grain in internal grinding by a composite abrasive wheel is considered. In particular, the transition from deformation to microcutting is analyzed on the basis of the Kragel’skii criterion.
244-247
Software correction of volumetric geometrical errors of multi-axis systems based on laser interferometric measurements
摘要
The article continues description of geometric errors laser correction for multi-axis NC-systems–CMMs and machine-tools. The Kalman’s concept of observability and controllability is applied to the method. In order to observe the multi-axis system a versatile laser measuring system is used, and in order to control the system a program postprocessor is proposed, introduced between CAD/CAM and NC-systems.
248-252
Energy losses in the electric motor of a high-speed spindle
摘要
Means of increasing the energy efficiency of high-speed spindles for micromachining are considered. Methods of calculating the losses in the electric motor’s stator yoke for a high-speed spindle are analyzed. Recommendations are made for the minimization of such losses.
253-257
Influence of clamping force on the machined surface in abrasive finishing
摘要
On the basis of the Preston hypothesis, it is possible to establish variation of the clamping force in the course of machining such that the contact pressure is stabilized and the productivity is increased. In the finishing of planes with different initial microrelief, the time dependence of the contact area is found to be exponential. The assumptions made in the analysis are experimentally verified in abrasive finishing on a Rastr 220 machine. With exponential variation in the force — that is, variation analogous to that of the contact area in abrasive finishing—the productivity is increased by a factor of 2.5–3.
258-261
Improved machining of heat-resistant materials by high-temperature embrittlement in cutting
摘要
The following hypothesis is verified: that heat-resistant materials are most easily machined at the temperature corresponding to their embrittlement. At that temperature, moreover, the mechanical characteristics ψ, δ of the material are least temperature-dependent. New methods are proposed for determining the conditions in which heat-resistant materials are most easily machined.
262-265
Precision of surfaces machined on a lathe with geometric errors
摘要
The precision attained in the shape and mutual position of cylindrical surfaces after machining may be assessed by means of a mathematical model. The effectiveness of the model is confirmed in practice.
266-269
Technological inheritance in the machining of titanium alloys
摘要
The surface quality and fatigue strength of structural titanium alloys are analyzed. Attention focuses on the work hardening, residual stress, fatigue strength, and the hydrogenation after machining in various conditions.
270-272
Measuring the optical density of wastewater by means of a diamond UV photodetector
摘要
Hydrocarbon pollution of wastewater is unavoidable in industry and transportation. Pollution monitoring, which forms part of environmental protection, may be based on measuring the optical density of water samples. In the present work, a device for this purpose based on a diamond UV photodetector and a nonmonochromatic UV source is described.
273-275
Erratum
Erratum to: “Manufacture of metal–concrete basic components for high-precision lathes”
276-276
Erratum to: “Optimal materials for the manufacture of metal-cutting machines”
277-277
