New Approach to Three-Coordinate Milling of Large-Sized Surfaces of Second Order

2021 ◽  
pp. 19-28
Author(s):  
S.N. Sayapin ◽  
O.O. Bryyndina ◽  
P.G. Vanina
Keyword(s):  
Spherical Surface ◽  
Second Order ◽  
Practical Implementation ◽  
Milling Machine ◽  
Surface Geometry ◽  
Machined Surface ◽  
New Approach ◽  
Technological Support ◽  
Milling Machines ◽  
Five Axis

The study introduces a new approach to precision machining of large-sized surfaces of second order on a three-coordinate horizontal milling machine. The new technology does not require the use of unique large-size boring lathes or five-axis milling machines. Three-axis horizontal milling machines do not need to be equipped with additional equipment that provides the workpiece with the missing rotational and translational movements relative to the machine table. The proposed technology is based on the use of a new approach that combines the geometric parameters of the second-order machined surface, the spherical surface of the cutting tool, i.e. cutter, and their position relative to the working table. The use of the developed technology will improve the efficiency and accuracy of machining the surface of second order, as well as simplify the control program and technological support due to the absence of movable equipment. The study gives an example of practical implementation and shows the possibility of independent control of the machined parabolic surface geometry using a three-coordinate horizontal milling machine.

Machining of Smooth Optical Surfaces by Ultraprecision Milling with Compensated Feeding Mechanisms

2019 ◽  
Vol 13 (2) ◽  
pp. 185-190
Author(s):  
Hideo Takino ◽  
Yoshimi Takeuchi ◽  
◽  
Keyword(s):  
Motion Control ◽  
Diamond Tool ◽  
Spherical Surface ◽  
Milling Machine ◽  
Machined Surface ◽  
Optical Surfaces ◽  
Positioning Errors ◽  
System A ◽  
Single Crystal Diamond ◽  
Single Crystal Diamond Tool

Waviness tends to be generated on cut surfaces even when an ultraprecision milling machine with a single-crystal diamond tool is used. The present study deals with the reduction of waviness by controlling the feeding mechanisms of the milling machine. A machining experiment on a spherical surface of a mirror element in a mirror array showed that the machined surface exhibited periodic waviness with a height of 30 nm and a wavelength of 300 μm. To investigate the reason for such waviness, a slope was machined under simultaneous multiaxis motion control of the feeding mechanisms of the milling machine. This proved that the interpolation errors of the encoders used in the milling machine produce the waviness on the machined surface when machining is carried out under simultaneous multiaxis motion control. To reduce such interpolation errors, the positioning accuracy of the machine stages was measured using a laser interferometer. On the basis of the measured results, the feeding mechanisms were compensated such that the positioning errors including the interpolation errors were corrected. Using the machine with the compensated feeding system, a mirror element was shaped. Consequently, waviness was reduced and the surface smoothness was less than 10 nm, demonstrating that such compensation can produce superior optical surfaces.

DEVICE FOR HONING PLANES WEDGES VALVES ARTILLERY SYSTEMS

2020 ◽  
pp. 37-42
Author(s):  
V. A. Bahvalov
Keyword(s):  
Metal Removal ◽  
High Strength ◽  
Gear Ratio ◽  
Work Piece ◽  
Milling Machine ◽  
Machined Surface ◽  
Vertical Milling ◽  
Milling Machines ◽  
Vertical Milling Machine ◽  
Kinematic Diagram

The article describes the process of honing the details of command artillery systems, in particular the process of honing planes wedge gate of medium-caliber guns. The article is an analysis of the kinematic scheme of the device and the selected gear ratio device that provides even wear a uniform honing stones and metal removal with a flat machined surface of the work piece due to the commission of the cutting grains honing stones complex movements in the horizontal plane. Next each of the cutting grains will not be repeated for the entire processing cycle. Kinematic diagram of the device with the established and enshrined in the radial grooves of the disc honing stones is implemented in the design and manufacture of devices for honing on vertical milling machines planes wedge gate artillery systems. Investigation of the process of honing the flat specimens made of high-strength gun steels viscous with plan dimensions 130x240 mm possible to determine the rational parameters of flat honing process.Production testing device for honing planes wedge gate of one of the artillery pieces on a vertical milling machine performed at one of the engineering confirmed the efficiency of the device for a flat honing. Honing wedge planes shutter serial products (76 mm caliber gun) on a vertical milling machine using the apparatus discussed in the article improves the processing performance in comparison with conventional processing means 20…35 %. In this case, stability is regulated product design documentation form accuracy and size of the part and the surface roughness of the planes of the wedge gate Ra £ 0,32 microns.

Experimental Analysis of Process Parameters to Manufacture Micro-Cavities by Micro-Milling

2012 ◽  
Vol 498 ◽  
pp. 91-96 ◽  
Author(s):  
J. Gomar ◽  
A. Amaro ◽  
E. Vázquez ◽  
J. Ciurana ◽  
C. Rodríguez
Keyword(s):  
Automotive Industry ◽  
Micro Milling ◽  
Geometric Features ◽  
Milling Machine ◽  
Machining Processes ◽  
New Approach ◽  
Biomedical Field ◽  
Dimensional Errors ◽  
Conventional Machining ◽  
Potential Opportunity

The use of conventional machining processes has been subject to important decline probably due to the increment in the use of emerging technologies. Therefore, the main applications of these traditional processes, such as automotive industry, are in crisis. In order to have a chance to compete successfully in the new trends, the machining industry must meet the needs of alternative sectors such as biomedical field. The aim of this study is to prove the capacity of micro-milling, by machining complex micro-cavities on aluminum workpiece using a conventional milling machine. Results are obtained by evaluating accuracy and geometric features. This study finds that the feed per tooth is a significant factor in order to obtain better results. The use of coolant increases the tool wear and therefore dimensional errors. This scope is a potential opportunity to reutilize the conventional machines from a new approach.

The Role of Cutter Eccentricity on Surface Finish and Milling Forces

2004 ◽  
Author(s):  
Tony L. Schmitz ◽  
Jeremiah Couey ◽  
Eric Marsh ◽  
Michael F. Tummond
Keyword(s):  
Surface Finish ◽  
Milling Machine ◽  
Time Domain Simulation ◽  
Machined Surface ◽  
Premature Failure ◽  
Series Of Experiments ◽  
Error Motion ◽  
Milling Forces ◽  
Chip Load

In this paper, the role of milling cutter eccentricity, commonly referred to as runout, is explored to determine its effects on surface topography and milling forces. This work is motivated by the observation that commercially-available cutter bodies often exhibit variation in the teeth/insert radial locations as a result of manufacturing issues. Consequently, the chip load on individual cutting teeth varies periodically, which can lead to premature failure of the cutting edges. Additionally, this chip load variation increases the roughness of machined surfaces. This research isolates the effect of runout on cutting forces and the machined surface finish in a series of experiments completed on a precision milling machine with 0.1 μm positioning repeatability and 0.02 μm spindle error motion. The runout is varied in a controlled fashion and results compared between experiment and a comprehensive time-domain simulation.

scholarly journals A Finite-Volume Icosahedral Shallow-Water Model on a Local Coordinate

2009 ◽  
Vol 137 (4) ◽  
pp. 1422-1437 ◽  
Author(s):  
Jin-Luen Lee ◽  
Alexander E. MacDonald
Keyword(s):  
Shallow Water ◽  
Finite Volume ◽  
Spherical Surface ◽  
Second Order ◽  
Water Model ◽  
Numerical Dissipation ◽  
Shallow Water Model ◽  
Finite Volume Model ◽  
Volume Model ◽  
Cartesian Coordinate

Abstract An icosahedral-hexagonal shallow-water model (SWM) on the sphere is formulated on a local Cartesian coordinate based on the general stereographic projection plane. It is discretized with the third-order Adam–Bashforth time-differencing scheme and the second-order finite-volume operators for spatial derivative terms. The finite-volume operators are applied to the model variables defined on the nonstaggered grid with the edge variables interpolated using polynomial interpolation. The projected local coordinate reduces the solution space from the three-dimensional, curved, spherical surface to the two-dimensional plane and thus reduces the number of complete sets of basis functions in the Vandermonde matrix, which is the essential component of the interpolation. The use of a local Cartesian coordinate also greatly simplifies the mathematic formulation of the finite-volume operators and leads to the finite-volume integration along straight lines on the plane, rather than along curved lines on the spherical surface. The SWM is evaluated with the standard test cases of Williamson et al. Numerical results show that the icosahedral SWM is free from Pole problems. The SWM is a second-order finite-volume model as shown by the truncation error convergence test. The lee-wave numerical solutions are compared and found to be very similar to the solutions shown in other SWMs. The SWM is stably integrated for several weeks without numerical dissipation using the wavenumber 4 Rossby–Haurwitz solution as an initial condition. It is also shown that the icosahedral SWM achieves mass conservation within round-off errors as one would expect from a finite-volume model.

Experimental investigation of the influence of cutting parameters on surface quality and on the special characteristics of micro-milled surfaces of hardened steels

2021 ◽  
pp. 095440622110130
Author(s):  
Barnabás Zoltán Balázs ◽  
Márton Takács
Keyword(s):  
Surface Quality ◽  
Surface Profile ◽  
Cutting Parameters ◽  
Relevant Information ◽  
Milling Process ◽  
Micro Milling ◽  
Machined Surface ◽  
Analysis Of Dynamics ◽  
Five Axis ◽  
Coated Carbide

Micro-milling is one of the most essential technologies to produce micro components, but due to the size effect, it has many special characteristics and challenges. The process can be characterised by strong vibrations, relatively large run-out and tool deformation, which directly affects the quality of the machined surface. This paper deals with a detailed investigation of the influence of cutting parameters on surface roughness and on the special characteristics of micro-milled surfaces. Several systematic series of experiments were carried out and analysed in detail. A five-axis micromachining centre and a two fluted, coated carbide micro-milling tool with a diameter of 500 µm were used for the tests. The experiments were conducted on AISI H13 hot-work tool steel and Böhler M303 martensitic corrosion resistance steel with a hardness of 50 HRC in order to gain relevant information of machining characteristics of potential materials of micro-injection moulding tools. The effect of the cutting parameters on the surface quality and on the ratio of Rz/ Ra was investigated in a comprehensive cutting parameter range. ANOVA was used for the statistical evaluation. A novel method is presented, which allows a detailed analysis of the surface profile and repetitions, and identify the frequencies that create the characteristic profile of the surface. The procedure establishes a connection between the frequencies obtained during the analysis of dynamics (forces, vibrations) of the micro-milling process and the characterising repetitions and frequencies of the surface.

scholarly journals High-temperature multilevel sterilization of canned goods with heat recovery and its constructive and technological support

2021 ◽  
Vol 247 ◽  
pp. 01030
Author(s):  
Mafiiat Rakhmanova ◽  
Amiiat Demirova ◽  
Magomed Akhmedov ◽  
Faina Azimova ◽  
Irada Gadzhibekova ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Heat Recovery ◽  
Experimental Studies ◽  
Cooling Water ◽  
Practical Implementation ◽  
Canned Food ◽  
Significant Saving ◽  
Technological Support ◽  
Thermal Sterilization

New technical solutions improving the process of thermal sterilization of canned products through the use of multilevel high-temperature modes and heat recovery have been considered and proposed. The essence of the developed method lies in the fact that the heat released by cooling cans with the product that has undergone thermal sterilization is used to heat other cans with the product queued for sterilization. In this mode of heat treatment, except in the last stage, the heat emitted by cooled cans that have already undergone heat treatment is used to heat up the canned food. Hence, the use of the principle of heat recovery by cooling canned products in the baths where others are simultaneously heated provides a significant saving of heat energy and water. Depending on the temperature parameters at different stages of the heat treatment, the heat recovery rate can reach up to 90%. The method also provides savings on cooling water. For the practical implementation of the developed method, the design of the device for multilevel high-temperature thermal sterilization of canned food with heat recovery has been developed. On the basis of experimental studies, new, multilevel high-temperature modes of apple compote sterilization have been developed.

Sign in / Sign up

Export Citation Format

Share Document