On the Improvement of Tool Life in Self-Piloting Drilling with External Chip Removal

Author(s):  
V P Astakhov ◽  
M O M Osman

This paper presents both the design and the method of grinding of self-piloting drills (SPDs) with external chip removal. The main advantage of the proposed SPDs over the standard SPDs is brought out using a comprehensive analysis of the SPD auxiliary flank design. The concept of increasing the cutting fluid pressure in the limited space between the tool flanks and the bottom of the hole being drilled by increasing the hydraulic resistance of the channel connecting this space and the chip removal passage is proposed. For the realization of the concept, the mathematical model for the auxiliary flank has been derived on the basis of the obtained condition for a free tool penetration into the workpiece. Using this model, the detailed grinding procedure for the proposed SPDs is explained. The two-stage experimental comparison of the standard and proposed SPDs shows that a significant improvement of tool life is achieved by using the proposed SPDs.

Author(s):  
Volodymyr Fedorov ◽  
Vladislav Kikot ◽  
Nataliya Shtefan

The article considers a two-stage gyrocompass with a rigid torsion suspension of the moving part. The principle of its action is based on balancing the elastic moment of the torsion bars with the gyroscopic moment. When this condition is met, the azimuth of the steady-state position of the rotor axis is calculated from the known kinetic moment , latitude and angular rigidity of the torsion bars, and the measured angle of rotation of the moving part of the gyroscope relative to its initial position. The “aging of the material” of the torsion bars, the effect of temperature on them, etc., leads to an uncontrolled change in the angular stiffness of the torsion bars, which, in turn, leads to an error in determining the position of the meridian. A method is proposed for determining the position of the meridian under conditions when the angular stiffness of the torsion is unknown. The method involves observing the motion of the gyroscope in a mode where the kinetic momentum changes linearly (the rotor accelerates). This movement is associated with the movement of the mathematical model of a two-stage gyrocompass in the same mode in the form of a differential equation of motion or in the form of its solution. As a result of minimizing the discrepancy between the real movement of the gyrocompass and the movement of its mathematical model, the “best estimate” of the parameter characterizing the position of the meridian and the “best estimate” of the angular stiffness of the torsion bars in this dimension are found. The results of modeling the corresponding information processing algorithms are considered. The advantages of the proposed method compared with traditional methods are indicated .


2012 ◽  
Vol 249-250 ◽  
pp. 636-641 ◽  
Author(s):  
Sheng Chen ◽  
Jian Zhang ◽  
Xiao Dong Yu

Optimization of closure law is the priority selection in solving the guaranteed regulation calculation problems due to its simplicity and economy. This present study deals with the optimization of two-stage closure law of wicket gates, which has more advantages in control pressure and speed rise. The mathematical model of transient process is established by introducing the method of characteristic, whose correctness is validated by the field test. Then the model is applied to a specific hydropower station that only can employ closure law optimization to coordinate the contradiction between pressure and speed rise, for two-stage closure optimization. The achievements of the study can serve as a reference for similar projects.


1995 ◽  
Vol 117 (4) ◽  
pp. 453-463 ◽  
Author(s):  
V. P. Astakhov ◽  
V. V. Galitsky ◽  
M. O. M. Osman

The performance of a self-piloting drill with external chip removal is affected by the geometry of its cutting tip. A comprehensive analysis of the cutting tip geometry and its influence on the drill performance is made. This subject is treated in two parts. In Part 1, the cutting tip geometry is analyzed. Special attention is given to the flank planes and a novel approach to the design of the drill was developed. By this approach the drill flank planes are located with minimum offset of the supporting pads’ faces relative to the plane of the drill corner’s rotation. Since several important drill angles are defined, the analysis is extended to cover the grinding process. The experimental comparison between the ordinary and newly designed self-piloting drills with external chip removal is also made to show the advantages of the latter.


Author(s):  
A.V. DOLOGLONYAN ◽  
V.T. MATVIINKO

A consideration subject in article is the mathematical model of pressure recovery factor of microgas turbine plants (MGTP) regenerators which considers dependence of hydraulic resistance of the heat–exchanger on the its surface area. Optimization of a regenerative cycle of MGTP and a cycle with regeneration and the turbocompressor utilizer for the purpose of further increase in their profitability is performed. It is established that use of the offered model of pressure recovery factor on the air and gas side allows to find degree of regeneration heattechnical optimum. This model can be used at simplified and predesign of MGTP.


Author(s):  
F.K. Sharshembieva ◽  
A. Sultankul kyzy ◽  
A.J. Zholborsova

Formulated the mathematical model of the problem of locating production with restrictions on the volume of production and goods transportation through transshipment points. Supposed method for solving this problem is placement. Numerical example has been construct for verification this the method.


2014 ◽  
Vol 1030-1032 ◽  
pp. 1224-1228
Author(s):  
Yu Lun Chen ◽  
Wei Qiu ◽  
Wei Min Ding ◽  
Yi Nian Li ◽  
Yu Tao Liu

In this paper, the mathematical model based on modern design methods of machinery used to optimize the parameters of the two-stage chain transmission system was established. The optimization toolbox of Matlab was introduced as well. Optimization results showed that, the pitches of first and second-stage chains were 19.05 and 25.4 respectively; compared with the original scheme, transmission ratio of first-stage chain decrease from 2.57 to 1.77, while the second-stage increase from 1.0 to 1.45. The number of chain strands of second-stage chain decreased from 2 to 1. The teeth number of the driven sprocket of the first-stage chain decreased also from 59 to 41. Total weight of the sprockets of the chain transmission system decreased from 25.40 kg to 14.84 kg, at least 41.57% material was saved and not less than 50% production cost was reduced. The optimization method is simple, feasible and the optimized parameters are reliable in practice.


2013 ◽  
Vol 2 (06) ◽  
pp. 21-31
Author(s):  
Alexandr Nikolayevich Shevtsov ◽  
◽  
Sagat Zhunisbekov ◽  

Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.


Author(s):  
Oleksii Timkov ◽  
Dmytro Yashchenko ◽  
Volodymyr Bosenko

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.


Author(s):  
Serhii Kovbasenko ◽  
Andriy Holyk ◽  
Serhii Hutarevych

The features of an advanced mathematical model of motion of a truck with a diesel engine operating on the diesel and diesel gas cycles are presented in the article. As a result of calculations using the mathematical model, a decrease in total mass emissions as a result of carbon monoxide emissions is observed due to a decrease in emissions of nitrogen oxides and emissions of soot in the diesel gas cycle compared to the diesel cycle. The mathematical model of a motion of a truck on a city driving cycle according to GOST 20306-90 allows to study the fuel-economic, environmental and energy indicators of a diesel and diesel gas vehicle. The results of the calculations on the mathematical model will make it possible to conclude on the feasibility of converting diesel vehicles to using compressed natural gas. Object of the study – the fuel-economic, environmental and energy performance diesel engine that runs on dual fuel system using CNG. Purpose of the study – study of changes in fuel, economic, environmental and energy performance of vehicles with diesel engines operating on diesel and diesel gas cycles, according to urban driving cycle modes. Method of the study – calculations on a mathematical model and comparison of results with road tests. Bench and road tests, results of calculations on the mathematical model of motion of a truck with diesel, working on diesel and diesel gas cycles, show the improvement of environmental performance of diesel vehicles during the converting to compressed natural gas in operation. Improvement of environmental performance is obtained mainly through the reduction of soot emissions and nitrogen oxides emissions from diesel gas cycle operations compared to diesel cycle operations. The results of the article can be used to further develop dual fuel system using CNG. Keywords: diesel engine, diesel gas engine, CNG


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