CN1073704C - Horizontal vibration sensor - Google Patents

Abstract

The present invention relates to a horizontal vibration picker. A vacuum container is arranged on a base; one end of a hang spring arranged in the container is fixed on the upper part of the container, and the other end is connected with a torsion pendulum rod which is suspended in the container; one end of the torsion pendulum rod is connected with a pendulum bob, and the other end is connected with balance mass; a noncontact acting force generator is arranged near the balance mass. The period of the existing horizontal pendulum vibration picker is raised from about 100 seconds to more than 1000 seconds by the present invention, and the present invention has the characteristics of high sensitivity, wide measuring frequency band, high stability, etc.

Description

A kind of horizontal vibration sensor

The present invention relates to a kind of geophone.

The geophone that uses all utilizes the horizontal pendulum principle to constitute at present, for example KS-1-H type horizontal vibration sensor adopts the hinging manner of spring-strip suspension and steel wire load-bearing to constitute, therefore, this geophone can't resolve and requires the big and little contradiction of stiffness coefficient of tensile strength; And for example GS-1-H type horizontal vibration sensor adopts combination cross-spring suspension structure, though can make the natural period that certain increase is arranged, owing to be subjected to the restriction of this inherent structure form of horizontal pendulum, makes its steady operation cycle be difficult to further raising.Therefore the existing horizontal pendulum cycle is generally about 100 seconds.

At the shortcoming of above-mentioned prior art, the task of cloth invention provides the outer dynamic balance of a kind of noncontact and rocks horizontal vibration sensor ultra-long period.

Ultimate principle of the present invention is on the analysis basis that is based upon traditional water yaw structure, and Fig. 1 is the structure principle chart of traditional water yaw.The pendulum quality is M, and the distance between the turning axle AB that it is extremely supposed is L ₀, the angle of actual turning axle of pendulum and AB axle is i, and instrument base is Φ at the pitch angle perpendicular to the i angle plane, and the fork required corner of state that restores balance is α, and the coefficient of torsion of suspension is C _D, then the linear-apporximation of this system motion equation is ${\mathrm{ML}}_0^2\frac{{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="C9610220700062.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{\&alpha;}}{{\mathrm{<figure-callout\; id="2"\; label="dt"\; filenames="C9610220700062.png"\; state="\{\{state\}\}">dt</figure-callout>}}^2}+({\mathrm{MgL}}_{0}l+C_D)\mathrm{\&alpha;}={\mathrm{MgL}}_0\mathrm{\&phi;}$ The horizontal pendulum cycle is $T=2\mathrm{\&pi;}\sqrt{\frac{{\mathrm{ML}}_0^2}{C_D+{\mathrm{MgL}}_{0}i}}$ Horizontal pendulum equilibrium point position is

α ^*=MgL ₀φ/(C _D+MgL ₀i)

Can find out obviously that from top two formulas there are following two subject matters in existing level pendulum geophone: the cycle of a. horizontal pendulum can not be very long.Theoretically, when the i=0 of inclination angle, its cycle can reach $2\mathrm{\&pi;}\sqrt{J/C_D}$ J is the pendulum moment of inertia in the formula, if regulate inclination angle i and make it to be negative value, then MgL ₀I shows as negative twist and transfers from one department to another number and satisfy 0＜C _D+ MgL ₀I＜C _D, this means horizontal pendulum long period can greater than But under actual conditions, because the influence of extraneous random disturbance and ground tilt tide, inclination angle i also changes thereupon.In order to guarantee C _D+ MgL ₀Always set up i＞0, must give i a rational initial value.In the ordinary course of things, can work steadily in the long term in order to guarantee horizontal geophone, MgL is always satisfied in choosing of i ₀I＞＞C _DThis condition.Therefore, the cycle of common horizontal pendulum mainly determined by inclination angle i, rather than by the coefficient of torsion C of suspension _DDetermine.Cycle of horizontal pendulum can not very long reason just for this.The cycle of existing horizontal pendulum is generally about 100 seconds.If can eliminate the influence of inclination angle i, the cycle of horizontal pendulum can reach more than 1000 seconds.As everyone knows, horizontal pendulum geophone cycle that the sensitivity and the linear response frequency span of earth pulsation response all is proportional to pendulum.Therefore, increase the cycle of horizontal pendulum and guarantee its energy steady operation, have very important significance for seismic study.B. the unstable working condition of horizontal pendulum.The front is talked about, and the variation of inclination angle i directly has influence on the stability in horizontal pendulum cycle.Correspondingly also make its sensitivity fluctuated, frequency span also changes along with the variation of i.The variation at i angle also directly has influence on the equilibrium point position (when the ground of other direction declination angle is non-vanishing) of horizontal pendulum in addition.From the equation of motion, the existence of φ and i also can bring nonlinear effect.Because the unstable working condition of horizontal pendulum geophone is brought great difficulty not only for the analyzing and processing of data, and has been reduced the credibility of measurement result.

Therefore, the technical measures that the present invention takes are for putting vacuum tank 1 on base 8, in vacuum tank 1, rock hang spring 2, one end is fixed on the top of vacuum tank 1, the other end with rock fork 3 and be connected, fork 3 is suspended in the container 1, one end of fork 3 connects with pendulum 4, the other end connects with balance mass 5, in the connection place of fork 3 and hang spring 2 catoptron 7 is set, and noncontact acting force generating means 6 is set near balance mass 5.Device 6 effect is to balance quality 5 a downward acting force is provided, but it does not directly contact with 5, and this power can be that electromagnetic force also can be the acting force of other character.

The present invention has the following advantages: 1. ultra-long period: existing level can be put about cycle from 100 seconds of geophone and bring up to more than 1000 seconds.2. high sensitivity: to before shaking faintly the remolding sensitivity existing level of pulsation detection pendulum geophone improve 10-30 doubly.3. measure bandwidth; The linear response frequency band is widened about 1mHz towards the low frequency direction, so more responsive to the remote seismic event of long period.4. high stability: horizontal vibration sensor of the present invention has only a suspension wire, rocks hang spring (2) vertically in gravity field.

Description of drawings is as follows:

Accompanying drawing 1 traditional horizontal vibration sensor structure principle chart

Accompanying drawing 2 horizontal vibration sensor structure principle charts of the present invention

Claims (1)

1. the geophone of a horizontal direction, it is by rocking hang spring, rock fork, pendulum, base constitutes, it is characterized by and put vacuum tank (1) on the described base (8), end that rocks hang spring (2) in vacuum tank (1) is fixed on the top of vacuum tank (1), the other end with rock fork (3) and be connected, fork (3) is suspended in the container (1), one end of fork (3) connects with pendulum (4), the other end connects with balance mass (5), fork (3) is provided with catoptron (7) with the connection place of hang spring (2), noncontact acting force generating means (6) is set near balance mass (5), noncontact acting force generating means (6) balances quality (5) a downward acting force is provided, noncontact acting force generating means (6) does not directly contact with this balance mass (5), and, rock hang spring (2) vertically in gravity field.

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