CN1188548A - Electrodynamic driving means for acoustic emitters - Google Patents

Abstract

An excitation assembly of a sonic source, in particular an excitation assembly of a sonic source applied in the study of the seismic research, has a vibration surface (1) which can vibrate, and includes a framework (4), which contains at least an excitation component (3,13) preferably located in the center. This excitation assembly also includes: two or more fastening devices (2) installed relative to the acoustic emitting surface (1), and placed on the reverse side of the framework (4); two or more flexible transmission components (5) linking the fastening devices (2) with one another, and extending on both sides of the axis between the two fastening devices; two or more second excitation components (6,7,16,17) connected with the transmission component (5), and combining with the first excitation components (3,13) to form an electromagnetic apparatus; and each of electromagnetic actuators is suitable to guarantee that the related excitation components (3,6,7, 16, 17) carry out a controlled vibration relative movement.

Description

The dynamic drive device of pinger

The present invention relates to the Drive assembly of acoustic wave source, this Drive assembly has the sound wave emissions surface that can be excited to vibrate, particularly relates to the Drive assembly of the acoustic wave source of using in the seismic prospecting.Technical field

Be used for to have such as sonar source, bending stretch source in the source of water generation sound wave, reaching earthquake transmitter or seismic energy source.The present invention can perform well in the source of these types, promptly is used for launching under water sound wave.When from sea bed and bottom geologic structure thing reflex time, the echoed signal of generation can be detected by various types of hydrophones or geology wave detector.

Known low-frequency sound wave can be by transmitting with the geologic structure thing in longer distance under water than high frequency sound wave.In the Military Application field and in the department of the ocean of oil and natural gas industry, have required to the powerful all-bottom sound wave source that can move under water for a long time always.Being used for the various structures in these purposes and field and the source of design also exists for a long time.These acoustic wave sources have such as in seismic energy source 1968 handbooks, Bendix, associating geophysics association 1968, and second the high-power sound wave and the ultrasonic transducers international discussion meeting paper collection of holding 12-13 day June nineteen ninety in France, forwarder needs the acoustic wave source described in the low frequency sonar.

Most of acoustic wave sources of Ying Yonging are impulse types now, and in this class acoustic wave source, strength mainly is invested in and will launches energy as much as possible in the short as far as possible time.The frequency content in this class source can only be revised in very little scope, thereby need select different sources for different exploration problems.

Recently having developed shape is the seismic energy source of Vib., and they can be in the various frequency band internal vibrations of so-called " frequency sweeping ".Belong to having of this type of seismic energy source and use the Vib. that hydraulic means moves and the source of applying piezoelectric or magnetostriction materials.In hydraulic vibrator, piston is controlled by valve arrangement, thereby it can obtain high amplitude.When known piezoelectric effect related to outside surface to crystalline material and applies voltage, its length changed, and on the contrary, produces voltage when material suffers physical deformation.Magneto-striction phenomenon means that when suffering changes of magnetic field, the length of magnetic material will change, and on the contrary, the length of material is changed the variation that will produce magnetic field.

The frame mode of acoustic wave source is diversified.To low frequency applications, when adopting hydraulic principle, the name source has circular surface (being shaped as piston) usually, and when applying piezoelectric or magnetostriction materials, then makes the source have xsect usually and be circular or oval-shaped cylindrical shape.

In marine vibratory device source, first rolls up at interval in 6, the 9 September 1988/285 phase and has described the notion of using the hydraulic piston source.

The greatest problem of this type of controllable source is will go to obtain quite accurately and enough big amplitude.For this reason, or need big surface, source, maybe need to have the little surface, source of high amplitude.

Vib. (for example in the offshore shooting method) based on hydraulic principle can provide the high amplitude under the low frequency.The motion of piston is controlled by valve arrangement.But, be limited together with the control degree of frequency for the amplitude in these hydraulic piston sources.

The principle of work of another kind of acoustic wave source is identical with dynamic loudspeaker, and it has the conductive coil and a permanent magnet that can produce controllable magnetic field.When coil was imported the electric current of variation, these two parts are relative motion mutually just.They transfer to make piston enter motion again, the water around vibration is sent to.The diameter of the piston roughly diameter with coil is identical.Find among series J-9, J-11 of USN that the example in these sources can be produced in the ocean resources company by Florida, US and the J-15.

There are many different sizes in these sources.They have frequency response relatively reposefully, but inefficiency.The efficient in big source is higher, but bandwidth is less.

Norw P 176457 has been described a kind of Drive assembly of acoustic wave source, and its basic structure comprises that an xsect is the oval-shaped cylindricality elasticity enclosure.There are two posts in this source near the main axis end, Drive assembly then is placed between this both ends post.

Bending stretch source with various sound wave emissions surface embodiment has been described in Norwegian patent applications number 941708 (international patent application no PCT/NO95/00071).

The objective of the invention is to propose a kind of Drive assembly that can in very wide frequency range, transmit.Except that method of seismic exploration, this Drive assembly can also be used for many different situations, such as with submarine sound wave, the application that the source is relevant with sonar.The shape on sound wave emissions surface can be according to the purposes change, and above-mentioned all different embodiment can use.

For reaching this purpose, a kind of Drive assembly has been proposed, its feature is according to claim 1.

Describe the present invention below with reference to accompanying drawing:

Fig. 1 from a side watch, the sectional view of one embodiment of the invention;

Fig. 2 represents the details of this electromagnetic driver;

Fig. 3 represents and corresponding section shown in Figure 1, but has the embodiment of different electromagnetic drivers;

Electromagnetic driver in Fig. 4 presentation graphs 3;

Fig. 5 represents an alternate embodiment of transfer member;

The front view of Fig. 6 presentation graphs 1 and 3 middle frames 4.

Represented one embodiment of the present of invention among Fig. 1, wherein transfer member 5 has the slightly shape of arch, and electromagnetism part 3,6 then is installed in the central authorities of framework 4 and transfer member 5 respectively.Transfer member 5 can be shaped as elastic plate or bar, and preferably is fastened on rotationally on the fastener 2.Distance from the middle body of transfer member 5 to the axis between the fastener 2 is less than 2 the distance from middle body to fastener.Thereby provide a kind of big motion to cause producing the transfer approach of the little motion of fastener 2 with corresponding bigger power with the excitation part 6 on the relatively little power generation transfer member 5.This transmission will be different and different according to the curvature of transport unit 5.If transfer member is a straight line substantially, then compare with the motion of driver, obtained frequency multiplication.

Fastener 2 shown in the figure is posts, but transfer member 5 is directly fastened on the sound wave emissions surface lip-deep fastening also can the making of sound wave emissions.

Sound wave emissions surface among Fig. 1 is oval-shaped.When transfer member 5 pulls to fastener 2 when interior, ellipse broadens, and produces pressure wave in the ring circulation around.The motion of electromagnetic driver will outwards be propagated in this way, cause sound wave in water.By the change of oval excentricity, the transfer rate in the Drive assembly is applicable to different circumstances.

In other embodiment on sound wave emissions surface, also can select other solution.As an example of fastener, they can be directly fastened on the piston, and wherein the motion that driver is big relatively will form the little motion of piston.In this embodiment, framework also can extend in outside the transfer member 5 at least in part, and like this, the described first excitation part just is placed on outside other excitation parts 6,7.

Fig. 2 has represented the electromagnetic driver among Fig. 1.This driver is made of two parts, and wherein the first excitation part 3 is fastened on the framework 4, and is made of permanent magnet material, and the second excitation part then is fastened on the parts in the transfer member 5, and is made of coil.When by the coil input current, produce magnetic field.This magnetic field will with the magnetic field interaction of magnetic parts, the relative motion that produces part.Can be expressed as with joint efforts:

F=ILB I herein is a electric current in the coil, and L is the length of conductor, and B is a magnetic flux density.

According to the difference of requirement power, maybe can change the size of electromagnetic driver, maybe can change the driver number on each transfer member 5.Also can adopt and place a plurality of transfer members, and on each transfer member 5, place one or more drivers along the axis of Drive assembly.But, if in the making a concerted effort of each side of framework, so that the stress drop on the works then is best to minimum with respect to framework axis symmetry.In structure shown in Figure 1, if the vector that forms is perpendicular to the main axis on oval sound wave emissions surface 1 with joint efforts, then this also is good.

Fig. 3 has represented the acoustic wave source suitable with Fig. 1, but has another kind of electromagnetic driver.The details of this driver is shown among Fig. 4.At this moment, driver is made of one first excitation part 13 and two second excitation parts 16,17, and coil is placed in the excitation of first on the framework part 13, and the second excitation part 16,17 then is passive magnetic part.Adopt this mode, than the symmetric motion that is easier to obtain these two second excitation parts.Coil 13 surrounds the core of magnetic material, as iron core, outwards guides magnetic field into for example also be fabricated from iron the second magnetic actuation part 16,17, and like this, the power F that acts on these parts can be expressed as: $F=\frac{N^2{\mathrm{<figure-callout\; id="2"\; label="I"\; filenames="A9619499300091.png"\; state="\{\{state\}\}">I</figure-callout>}}^2}{{\mathrm{\&gamma;}}_{\mathrm{tot}}^2{\mathrm{\&mu;}}_{\mathrm{gap}}{\mathrm{\&mu;}}_{0}A}$ N is the number of winding herein, and I is an electric current, γ _TotBe magnetic resistance, μ _GapBe magnetoconductivity, μ _oBe space permeability, A then is an area.

Fig. 5 has represented another embodiment of transfer member, and this transfer member is made up of the bar of relative stiffness, and every bar at one end is fastened on the second excitation part 6 rotationally, then is fastened to rotationally on the fastener 2 at the other end.When excitation part 6 outwards moved, the other end of bar was pulled inwardly with above-mentioned transfer rate.Ratio between these motions equals b/a in the case.

Fig. 5 has also represented another embodiment of excitation part among Fig. 2, and it is also made by a control lever here, and this bar is placed by the center of coil 6 and magnet 3 and moved steadily with assurance.

Fig. 6 has represented the front view of framework 4, and it has the hole 8 that is used to install the first excitation part 3,13 that some centers are provided with, and the bolt 9 that is used for corresponding fastener is fastened to the acoustic wave source (not shown).When using more than one electromagnetic driver, framework can be equipped with the hole of more fastening these parts.

Claims (11)

1, the Drive assembly of acoustic wave source, the Drive assembly of the acoustic wave source of using during particularly seismic method is studied, this Drive assembly has the vibration surface (1) that can vibrate, and comprise a framework (4), this framework (4) comprises a preferably excitation part (3 of centering at least, 13), it is characterized in that described Drive assembly also comprises:

Two or more relative sound wave emissions surfaces (1) and install and be placed on fastener (2) on the another side of framework (4);

The elasticity transfer member (5) that two or more are interconnected fastener (2) and extend the axis both sides between two fasteners;

It is that two or more are connected with transfer member (5) and be provided with described first excitation part (3, the 13) combination constituting the second excitation part (6,7,16,17) of electromagnetic driver,

And each electromagnetic driver is suitable for all guaranteeing that relevant excitation part (3,6,7,16,17) carries out the controlled vibration relative motion betwixt.

2, Drive assembly as claimed in claim 1 is characterized in that, has at least a transfer member (5) preferably to be made up of elastic plate.

3, Drive assembly as claimed in claim 1 is characterized in that, has at least a transfer member (5) to be made up of elastic rod.

4, the described Drive assembly of one of claim as described above is characterized in that transfer member (5) has curve shape.

5, the described Drive assembly of one of claim as described above is characterized in that one or more electromagnetic drivers are installed with respect to each transfer member (5).

6, the described Drive assembly of one of claim as described above, it is characterized in that, have at least one to be made of bar in the transfer member, an end of every bar is fastened on the described second excitation part rotationally, and the other end then is fastened on the described fastener (2) rotationally.

7, the described Drive assembly of one of claim as described above is characterized in that, each electromagnetic driver (3,6,7,13,16,17) is made of a current coil (6,7,13) and one or two magnetic material part (3,16,17).

8, the described Drive assembly of one of claim as described above is characterized in that, is arranged on the excitation part (some encourage part) (3 on the framework (4), 13) position is than the described second excitation part (6,7,16,17) axis between the more close fastener (2).

9, the described Drive assembly of one of claim as described above is characterized in that electromagnetic driver (3,6,7,13,16,17) is provided with symmetrically with respect to the axis between the fastener (2).

10, Drive assembly as claimed in claim 9 is characterized in that, described first (3,13) and second (6,7,16,17) excitation part and two fasteners (2) the identical distance of being separated by, be installed in respectively on framework (4) and the transfer member, and first (3,13) and second (6,7,16,17) axis normal between the basic and fastener (2) of the direction of the relative oscillating movement of excitation between the part.

11, the described Drive assembly of one of claim as described above, it is characterized in that the distance between the fastener (2) will be much larger than the described second excitation part (6,7,16,17) two ones of the tie point on the transfer member (5) to the distance of axis between the fastener (2).

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