Use Of Cuttings Research Articles

ВЛИЯНИЕ АРМИРУЮЩИХ МАТЕРИАЛОВ ГОРНОРЕЖУЩЕГО ИНСТРУМЕНТА НА ВЗРЫВОБЕЗОПАСНОСТЬ ИХ ПРИМЕНЕНИЯ

In many cases, the cause of explosions of dangerous concentrations of dust-methane-air mixtures in coal mines is the frictional contact of the ends with the destroyed mountain massif. In this regard, many scientists are conducting studies on the explosiveness of the use of cutters in mines, but they are mainly aimed not at establishing the causes of methane ignition, but at improving the systems for the pressure of methane flares. The probability of methane ignition, along with other factors, depends on the reinforcement material of the mining tool, which is one of the controversial issues of Russian and foreign researchers. In this regard, studies were carried out aimed at establishing the influence of various materials reinforcing cutters on the likelihood of methane ignition during rock cutting, for which a special stand was made. The results of the experiments showed that the explosions of the methane-air mixture are determined not by the intensity of sparking of the cutter material when it wears out, but by the accumulation of thermal energy, when the critical level of which is reached, the mixture explodes. Moreover, critical energy is achieved faster when cutting rock with harder reinforcing materials.

IMPROVED REMOVAL FROM THE CUTTING AREA WHEN TURNING WITH AN INTERNAL AIR-COOLED CUTTER

The article studies the influence of design solutions on heat sink when turning with a cutter with internal air-cooling. A cutter design with increased heat sink has been developed. This design allows to significantly expanding the scope of use of cutters with internal air-cooling instead of traditional cutters with coolant.

Evaluation of the permissible moment in a roller cone drill bit providing the prescribed reliability of work

After analyzing the nature of the damage of surfaces was discovered the traces of the compression effect which arise along the cutters axis when squeezing it into the rock of delve. There were also founded the traces of deformation from the action of bending to the cutter, depending on the orientation of its slip on the face. We noticed the rubbing, fretting-corrosion, damage the local areas of the apertures walls caused by scrolling the cutter around its axis in the aperture of cones crown. In the case of the use of cutters with symmetrical aggravation of the rockdestructive part, the orientation of the generating line of active part of the cutter is determined by an effective angle to the axis of the crown of the cone. Calculations show that an angle of 45° is optimal. We noticed the rubbing, fretting-corrosion, damage the local areas of the apertures walls caused by scrolling the cutter around its axis in the aperture of cones crown. The analysis of types of rock-destructive equipment of cones damages has been revealed that with increasing the magnitude of the axial load on the bit, cases of splitting, destruction of hard-alloyed cutters increase. For this purpose, it is necessary to protect the drill`s crowns from cementation. If carbide cutters are located in several rows in the cone drill, then milling of the sites on cemented layer`s depth is effective. This prevents the removal of parts of cone`s crown. The allowable moment is proportional to the square of the height, so the connections which perceive the considerable bending moments cannot be performed with small values of the diameter or small height of the cutter shank.

Recycling possibilities for reducing waste from cutters on combined cutter-loaders and road builders.

The objective of this study was to find opportunities for metal waste recycling in the process of rock breaking in mines. A built-up cutter design for a combined cutter-loader and a recycling technique for a considerable portion of the deteriorated tool are suggested. Industrial tests have proven the possibility of a ten-fold increase in the use of cutters on mining machines for coal rock mass destruction. The proposed technique allows a four times reduction in metal consumption in the production and use of cutters and a reduction of the ultimate resulting waste by 80%. This advanced technique could be transferred extensively into such industries as open-cast mining, repair of motor-roads, construction and agriculture.

Studies on the Bush Cutter equipped with a Fixed Blade (3)

To assess the degree of safety to the machine operators, we checked into the conditions of cut grass and pebbles scattered in operation of two types of bush cutter, one the cutter with a specially designed fixed (stationary) blade and the other an ordinary blade of 8-tooth and nylon wire. The major results obtained are summarized as follows.1) After mowing Digitaria adscendens Henr. in the experiment, were checked into the traces of cut pieces of the grass and the grass juice left on the operator's clothes. In the use of nylon wire cutter, which cuts the grass with centrifugal force, the traces were conspicous on the operator's waist and below. In 30 minute operation, operator's right and left knees accounted for about 80% of the entire area of the traces(trace area of cut objects cm2/100cm2). In the use of the cutter with a fixed blade and an ordinary 8-tooth blade, scattering of the cut grass was less. Scattering was much less (ratio of trace area 0.1%) with the fixed blade cutter which is designed to reduce the rotating speed of the cutter blade to about 1/3 of that of an ordinary blade.2) Scattering of ceramic triangular pyramids (DIN specification) from the fixed blade cutter was less than that of an ordinary 8-tooth blade. The result is due to the lower rotating speed of the cutter blade of the former cutter and also to the crushed objects being contained or being prevented from scattering by the fixed blade.3) Scattering direction tended to be in the left side of the operator with all of the fixed blade cutter, an ordinary 8-tooth blade and nylon wire cutter. Scattering density number of scattered objects in the operator's position with the fixed blade cutter was down to half (1/2) of that of an ordinary 8-tooth blade and nylon wire cutter.4) Scattering height with the fixed blade cutter and an ordinary 8-tooth blade cutter was less than 50cm. Scattering density at each designated height in the operator's position was lower for the fixed blade cutter than that of an ordinary 8-tooth blade cutter which leads us to determine that the danger from scattered objects decreases in using the former type of the machine.

Use of cutters reinforced with Elbor R and Hexanit R for machining quenched steels and cast irons

Use of cutters reinforced with Elbor R and Hexanit R for machining quenched steels and cast irons