SU1368705A1 - Method of determining strength of materials - Google Patents

Abstract

The invention relates to a mining case. The purpose of the invention is to increase the accuracy of determining the strength and expand the range of materials under study. Destroy the material by rotating and vibrating the tool: -1ent. A power ratio is adopted for the drive of the vibration of the instrument and for the drive of the rotation of the instrument, set according to the minimum energy of destruction of the material under study. The minimum energy is set automatically by distributing the power of the primary differential mechanism to a uniform rotation and drive of the oscillator and summing these motions on the working tool. The uniform and oscillatory rotations are summed in the secondary planetary gear stage. The strength of the material is determined by the frequency of rotation of the tool or the vibrator shaft. The optimal dynamic destruction mode is determined by the boundary value of the contact time of the tool with the face. 1 hp f-ly, 4 ill. with (L

Description

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The invention relates to mining and is intended to determine the strength of rocks, soils, building materials, and bulk materials.

The aim of the invention is to improve the accuracy of determining the strength and expand the range of materials under study.

FIG. Figure 1 shows the dependence of the energy intensity of destruction on the tool revolutions; in fig. 2 shows the dependence of the specific destruction volume on the contact timeJ in FIG. 3 shows the dependence of the drive power on the oscillation frequency in FIG. 4 shows the relationship between drilling speed and drive power.

The method of determining the strength of materials is to destroy the material by rotating and vibrating the instrument with a ratio of powers to the drive of the instrument to vibration and to the drive of the instrument to set the minimum energy of destruction of the material under investigation, which is set automatically by, for example, power distribution by the primary differential mechanism. for uniform rotation and drive of the exciter of oscillations and summation of these moving tool tools. Uniform and oscillatory rotation are summarized in the secondary planetary gear stage. The strength of the material is determined by the frequency of rotation of the tool or the shaft of the vibrating drive.

The optimal dynamic destruction mode is determined by the boundary value of the contact time of the tool with the face. This time has been established experimentally for various rocks (Fig. 1) and has a pronounced minimum specific energy intensity of destruction for various axial forces. The contact time of the tool with the bottom for a certain type of destructive tool, in particular a roller cutter, is proportional to the rotational speed of the rod, since here the dynamics of the destruction process is determined by the number of pins on the working surface. is 12 ms (point B, fig. 2), and with the same load for granite it is equal to

7-8 ms (point A, fig. 2). In the first case, the boundary number corresponds to 63 rpm, in the second - 100 rpm.

The boundary time of contact of the tool with the bottom determines the optimal parameters of the pulse effect on the materials, the pulses of the vibration exciter are summed with a uniform rotation of the drill rod. The contact time determined from the equation of motion depends on the frequency of oscillation.

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where f is the oscillation frequency,

contact time factor depending on the rate of growth of the rate of application of the load at the beginning and end of the path of a single pulse.

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The contact equation of the tool does not reflect the complete process of pulsed destruction, since it does not involve the second main factor of oscillations — the amplitude of oscillations. But the amplitude is less

determines the optimal modes of action on materials and in dynamic exciters of oscillations depends on the frequency (inertia force. Fig. 3 shows the dependences of the drilling rate, the power consumed by the exciter of oscillations and the rotator on the oscillation frequency in comparison with the speed of ordinary (Vo) and the power of ordinary (N) drilling.

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The power consumed by the uniform rotation of the drill (Nj; when set, has a pronounced minimum, and the drive power of the exciters (NJ increases almost in proportion to the square of the oscillation frequency).

For rocks of different strengths with a rotation frequency of 52 rpm, an oscillation amplitude of 2 mm, an oscillation frequency of f 28 Hz (Fig. 4), the power of conventional drilling (N), the drive power of uniform rotation (Ng) change much more intensely than the drive power pulsator (MI) The physicomechanical properties of materials determine the minimum specific energy intensity of destruction due to the intensity of dynamic effects (Fig. 1).

The time of contact of the tool with the bottom for different materials varies (Fig. 2), the drive power of uniform rotation has a minimum consistent with the time of contact of the tool with the face, and the drive power of the oscillator increases with the oscillation frequency (Fig. 3). In addition, both of these powers, according to different laws, vary as a function of the strength of the rocks (Fig. 4).

Thus, the minimum of the energy intensity of the dynamic destruction stabilizes the rotational speed of the drive shaft of a uniform rotation and, due to the redistribution of power in a two-way differential mechanism, provides a certain frequency of rotation of the vibration drive shaft. Measurement, for example, of this magnitude of rotational frequency determines the strength of the material.

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Mula .Isobre. The method of determining the strength of materials, including the destruction of a material with a tool and measuring the forces of destruction, characterized in that, in order to increase the accuracy of determining the strength and expand the range of materials under study, the destruction of a material is performed by rotating and vibrating the tool when the ratio of power to the vibration of the tool and on the drive of rotation of the tool, installed by means of 15 to the minimum of the energy of destruction of the material under study, and the strength of the latter is determined by the frequency of rotation of the tool NTA.

2. A method according to claim 1, characterized in that the ratio of powers to the drive of the vibration of the instrument and to the drive of rotation of the tool is established by means of a differential mechanism.

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Claims (2)

Claim 1. A method for determining the strength of materials, including the destruction of the material by the tool and measuring the destruction forces, characterized in that, in order to increase the accuracy of determining the strength and expand the range of the materials under study, the destruction of the material is carried out by rotation and vibration of the tool with a ratio of power to drive the vibration of the tool and on the drive rotation of the tool installed on Thus, the minimum energy-jg of the dynamic fracture bone stabilizes the number of revolutions of the drive shaft of uniform rotation and, due to the redistribution of power in the dual-flow differential mechanism 20, provides a certain frequency of rotation of the shaft of the vibrodrive. For example, measuring this frequency value in front of the minimum destruction energy of the material under study, and the strength of the latter is determined by the frequency of rotation of the tool. 2. The method according to claim 1, characterized in that the ratio of powers to the tool vibration drive and to the tool rotation drive is established by diffusion and determines the strength of the material. potential mechanism. Fie. Ζ