RU2302300C1 - Seismic vibration oscillation source - Google Patents

Abstract

FIELD: controlled sources for generating seismic vibration oscillations designed for prospecting minerals, investigating Earth, predicting earthquake.

SUBSTANCE: seismic vibration oscillation source includes irradiating plate; pulse generators of different-polarity efforts with inert masses having springs and shock absorbers; overweight mass. Seismic vibration oscillation source has at least four pulse generators for generating different-polarity efforts forming in plan view rectangle. Said generators are mounted with possibility of motion one relative to other and relative to overweight mass. Each generator provides half of target effort and each includes half value of inert mass. Control systems of different-polarity effort generators are connected in pairs in diagonal directions.

EFFECT: enhanced energy factors of source due to its increased power coefficient.

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Description

The invention relates to vibrational sources of seismic vibrations, mainly to vibroseismic sources, designed to search for minerals, study the structure of the Earth, earthquake prediction.

Known vibration source with adjustable amplitude of the oscillation forces and their frequency, comprising a housing and an unbalance provided with a channel in which a spring is placed, interacting with a stop and a sleeve equipped with adjusting screws [Copyright certificate. USSR No. 232075. Cl. At 06 In 1/16, 1967].

The disadvantage of such a vibro-seismic source is low reliability due to large loads on the unbalance movement drive mechanism and the limited unbalance stroke determined by the dimensions of the drive movement mechanism.

Closest to the invention in technical essence and the achieved result is a vibration source (prototype) containing a radiating plate, an inert mass and a variable-force generator installed between them with a spring and a shock absorber [Ivashin V.V., Miloradov I.A., Simkin S.A. ., Chichinin I.S. Resonant matching circuits of the vibrator with the ground. In the book "Problems of vibrational transmission of the Earth", Moscow: Nauka, 1977, 238 pp., P. 121].

The disadvantages of such a vibro-seismic source are very low energy indicators, especially at low frequencies, poor ground alignment, the need to control the stiffness of the springs and the introduction of a complex tracking system for the inertial mass when the vibration frequency changes and the very low power factor of the vibrator-soil system. This coefficient, especially in the resonance mode, approaches zero, which gives, accordingly, a very low coefficient of efficiency of the vibration source.

The objective of the invention is to increase the energy performance of the vibration source by increasing its power factor.

This problem is achieved by the fact that in a vibro-seismic source containing four impulse generators of different polar forces, forming a rectangle in plan, moreover, generators of different polar forces are mounted movably between each other and with a loading mass, create each half of the required force, each have half the total required inert mass, systems control generators of heteropolar efforts in diagonal directions are included in pairs.

Figure 1 is a cross-sectional view of a vibro-seismic source with a view along BB in figure 2, figure 2 is a cross-section with a view along AA in figure 1.

Figure 3 shows a timing diagram of the creation of the resulting forces and vibration velocities of the inert masses of the vibro-seismic source with two force impulses of forces on the half-cycle of oscillations.

Figure 4 shows the dependence of the shear angles φ between the total force and inertia vibration velocities and the dependence of the power factor Cosφ of the emitting plate on the number of impact pulses at each half-cycle of the generated vibroseismic vibrations.

Vibro-seismic source (1, 2) contains at least 4 inert masses 1, 2, 3, 4, which are mounted on the radiating plate 5 through springs 6, 7 and shock absorbers 8, 9. Each inert mass is driven by pulse generators of different polar forces 10, 11 and 12, 13 (not shown), respectively. The radiating plate is pressed to the ground by the unloading mass 14 through the springs 15, 16 and shock absorbers 17, 18. In addition, the inert mass 14 in its upper part is connected with the inert masses by the springs 19, 20 and shock absorbers 21, 22. The inert masses are mounted movably and between each other and with a loading mass of 14 and with respect to the radiating plate 5. Inert masses 1-4 together with their vibration exciters form a rectangle in plan.

On figa shows the formation of the force F _1,4 force generators located on the diagonal of the rectangle of the vibration source, Fig 3b shows the formation of the total force F _2,3 force generators located on the other diagonal of the rectangle of the vibration source.

Figure 4 shows the dependences of the angles φ and Cosφ on the number of pulses of force actions on each half-cycle of oscillations. The power and control system in figure 1, 2 is not shown.

Vibroseismo works as follows. At the same time, force generators are turned on, acting simultaneously on inert masses 1, 4 or 2, 3 (Fig. 1) in accordance with the time diagram of Fig. 3, which shows the formation of the resulting rectangular force F _1-4 (Fig. 3c), created alternately efforts F _1.4 or F _2.3 (figb). Vibrational velocities V _1.4 or V _2.3, to the next action of the opposite form, decay to zero, which ensures a resonance-free mode of the vibration source at all operating frequencies. Moreover, the power factor of the vibro-seismic source even with two power actions on the emitting platform is 0.7 versus Cosφ = 0 with simultaneous (single) operation of all 1-4 vibration exciters, when this number of pulses in accordance with Fig. 4 is equal to unity.

Figure 4 shows the dependences of the shear angles φ and the corresponding power coefficients Cosφ for various values of the number of impact pulses N in each half-cycle of the generated oscillations. So, for the number of pulses N = 6, we obtain Cosφ = 0.96. Such a vibro-seismic source with the proposed method of power and control is especially effective when operating at low and ultra-low frequency vibrations. Until now, all low-frequency vibration sources have had a sharply hyperbolic inversely proportional dependence of the oscillation power on their generated frequency. The latter did not allow obtaining stable operation of these sources at frequencies below 5-6 Hz. The operation of the proposed vibro-seismic source in resonance-free modes greatly simplifies its management. Any pathogen can be used as a power pulse generator - electromagnetic with additional excitation, electrodynamic-pulse, linear synchronous and valve exciters.

The design of the proposed vibro-seismic source, in addition, has good energy compatibility with the power supply system, which allows you to create these vibro-seismic sources for any required efforts and, accordingly, any power. The absence of rotating and moving masses also provides easy synchronization of any number of vibration sources.

Thus, the proposed vibration seismic source has a high power factor and, accordingly, high energy performance especially at low vibration frequencies, which ensures the fulfillment of the task.

Claims (1)

A vibro-seismic source containing a radiating plate, pulse generators of bipolar forces with inert masses with springs and shock absorbers, a loading mass also with springs and shock absorbers, a power and control system, characterized in that the vibro-seismic source is made of at least 4 pulse generators of bipolar forces forming a rectangle in plan, moreover, generators of bipolar forces are mounted movably between themselves and with a loading mass, they create each half of the required effort, each has CVID total required quantity of the inertial mass, generator control system bipolar efforts included in diagonal directions in pairs.

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