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Abstract: Optimization of the parameters of the operating organ of the tunneling combine according to the criterion of the cutter wearing

Content

Introduction

Roadheader (PCs) are designed to carry out preparatory mine workings. [7] Their application allows to mechanize the basic processes of the tunnel loop – the destruction of the rock, its removal from the face of development and the loading on the vehicle.

To PC presented a number of general requirements, the main ones are:

  1. High values the basic parameters of macro-level, integrated characterizing their quality and the degree of competitiveness in the mining representative operating conditions: the maximum possible theoretical and technical capacities; 80% strength Overhaul;
  2. A comprehensive coverage of possible areas of use: on the sizes and shapes for different purposes workings (drifts, salable, and so on) with minimum iterating breed; the fortress destroyed and abrasive rock;
  3. Sufficiently low specific energy consumption unit during operation;
  4. Ergonomic ease of operation, high safety, and required hygienic conditions at work staff.

1 Theme urgency

The efficiency of coal mines, depends on the level of mechanization and automation of mining operations. One of the areas to reduce the cost of the mineral is the concentration of mining. Achieving this requirement is only possible by using modern technology, provided that they are using the best possible potential of technology by adapting it for the mining and technical and geological conditions of the mine.

Structural model of axial crown

Figure 1 – Structural model of axial crown

The destruction of the cutter rock mass

Figure 2 – The destruction of the cutter rock mass
(animation: 10 frames 10cycles of repetition, 144 kilobyte)

While working in the mine tunnel boring machine, namely the destruction of the mountain range – the whole process is accompanied by a continuous wear due to abrasion of the cutter rock, and in some cases complete, [5] instantaneous output of the tool system, which is typical in contact with the cutting area of solids. All of the above leads to an increase in specific energy, high dynamic loads (impacts) that leads to a decrease in theoretical performance of the machine, therefore, increases the duration of the volume of the rock mass failure, which leads to an increase of load cycles – all this leads to life reduction of the whole machine, and deviation of the technical level of the standard indicators.

2 Goal and tasks of the research

The aim of the study is to optimize the parameters of the executive body of miner combine to reduce tool wear.

Main tasks of the research:

  1. Develop a program for the evaluation of the resource elements of heading machine by rainflow. Experimental data were obtained using a mathematical model developed at the Department of mining machines;
  2. Set the effect of wear on the cutter heading machine performance;
  3. Set the effect of wear on the cutter transmission resource elements;
  4. Association of functionally different optimization directions of Moore FSM hardware amount into the unified approach to synthesis and formation recommendations for it's use;
  5. Develop a model of optimization schemes set incisors criterion of wear.

Research object: workflows executive heading machine.

Research subject: the parameters of the executive body, providing a reduction of specific energy consumption and increase the resource of the cutting tool.

3 Evaluation of the design characteristics of loading

The nature of the changes in time, you can load [1] divided into regular and irregular.

Regular loading in accordance with state standard 23207–78 called loading characterized by periodic changes in load with one maximum in one period at a constant cycle parameters voltage during the test [6] period or operation. All types of loads which do not meet this definition is called irregular. These include biharmonic, polyharmonic, block and random loading.

In most instances, there is a random nature of the change in time of stress. In our case, we have a large-loading process in time (Fig. 3).

Diagram of broadband strain

Figure 3 – Diagram of broadband strain

In the case of broadband process (Fig. 1) to release the voltage amplitude, have a major impact on the accumulation of fatigue damage, can be approached in different ways. Schematization random processes, the purpose of which is to obtain the distribution function of the voltage amplitude equivalent to a given random process of insertion degree of fatigue damage. For wideband processes results could differ, sometimes these differences are very significant. It is considered that the most reasonable results for the assessment of durability provides a method of complete cycles.

Widespread method, called the method of rainflow state standard 25.101–83 [2]. This method results in substantially the same results as the method of complete cycles, but it is more convenient to be programmed on a computer. The meaning of such a cycle, [2] that the time axis is directed vertically downward. Let the lines connecting neighboring extremes – a sequence of roofs, which drain into torrents of rain. Non maxima correspond to odd numbers, even numbers lows. The flow path is determined according to the following rules:

  1. Thread starts on the inner side of the extrema in series. Each thread defines a half-cycle loading. The value of the scope determined by the projection of the flow path on the axle load.
  2. The stream, which began at the maximum point, interrupted at the moment when he meets a larger maximum, larger than the original.
  3. Feed started at the minimum, is interrupted when he meets at least smaller than the original.
  4. At a meeting on one of the roofs of several traffic flow continues to the one that originates in the extremum with a lower number, and the rest are interrupted.
  5. The flow without encountering obstacles, falls to the ground.

The method of rainflow allows you to enter schematization in real time. At the same time remembering a path rain and streams processing is performed as you type extremes.

Based on the foregoing was [3] composed of a block diagram of the method (Fig. 2).

General algorithm of the <q>rainflow</q>

Figure 4 – General algorithm of the rainflow

Using the algorithm and compiled flowchart and use developed by the Department mining machines mathematical model to determine the loading sequence diagrams – ask loop (Fig. 3) to determine the streams running down from the roofs of straw

Cycle method <q>rainflow</q>

Figure 5 – Cycle method rainflow

Conclusion

In the master's work scientific representations of solutions – technical issue of great importance the national economy, is to optimize the parameters of the executive body of miner combine tool wear criterion, allowing to increase the rate of mining and life extension of structural elements of the machine.

References

  1. Kogaev V.P., Makhutov N.A., Gusenkov A.P. The calculations of machine parts and structures for strength and durability: A Handbook. – M.: Engineering, 1985.  – 224 c.
  2. Interstate standard. Calculation and testing for strength. Methods schematic random loading processes mshiny elements and structures and static presentation of the results. GOST 25.101–83
  3. Grigorieva Olga. Engineering methods for assessing the strength and durability of links and anchor risers offshore structures. Thesis for scientific degree of candidate of technical sciences. 05. 23. 17 Structural Mechanics. St. Petersburg, 2009.
  4. Bridun Igor. Justification of the criteria and the structure of funds of technical diagnostics executive heading machine. The thesis for the degree of candidate of technical sciences. Profession 05. 05. 06 mining machines. SACs 622.232.7. Donetsk, 2014.
  5. DSTU 3625–97 Combines sinking. Terms and Definitions.
  6. Fatigue resistance. Basic terms, definitions and symbols. GOST 23207–78
  7. Mining machinery for underground coal mining: Textbook for High. Gorbatov P. A. and etc.