CN114674411A - Fiber grating hydrophone adopting double cymbals-shaped diaphragms - Google Patents

Abstract

The invention relates to a fiber grating hydrophone adopting double cymbals-shaped diaphragms, belonging to the technical field of fiber hydrophones. The outside cover of support drum has the rubber sleeve that passes through the sound, and support drum both sides rigid coupling left shell and right shell respectively, and the inside symmetry fixed mounting left cymbal shape diaphragm of support drum and right cymbal shape diaphragm are installed left copper sheet and right copper sheet on the diaphragm and are used for fixed fiber grating, and fiber grating passes the hole on the hydrophone axis. The advantages are that: the volume change of the oil cavity caused by the sound pressure is converted into the length change of the fiber grating by using the cymbal-shaped diaphragm, the structure is simple, on the basis, the characteristic that the cymbal-shaped diaphragm is not easy to deform is utilized, and the reliability and the stability of the structure are improved by adopting a mode that the diaphragm is fixedly connected with the supporting cylinder.

Description

A Fiber Bragg Grating Hydrophone Using Double Cymbal Diaphragms

technical field

The invention belongs to the technical field of optical fiber hydrophones, and in particular relates to a fiber grating hydrophone using double cymbal-shaped diaphragms.

Background technique

Sound waves are the only form of energy known to man that can travel long distances in seawater. A hydrophone is a type of sensor used to detect underwater sound waves for navigation, measurement and communication. Traditional hydrophones can be divided into electric type, capacitive type, piezoelectric type, etc. according to the principle of detecting underwater acoustic signals.

In recent years, with the rapid development of fiber light source, fiber spectrometer and fiber grating processing technology, fiber grating hydrophone with high performance, miniaturization and high stability is gradually called a new generation of underwater acoustic detection sensor. The fiber grating hydrophone with fiber grating as the sensing source has received extensive attention from domestic and foreign scientific research institutions and scholars in the fields of national defense, military, detection and other applications, and related technologies have achieved unprecedented development. Compared with other types of hydrophones, fiber grating hydrophones have the advantages of low noise, high sensitivity, large dynamic range, and excellent reliability. The packaged optical fibers are used as connectors, which are very suitable for forming large-scale hydrophones. Arrays, fiber optic hydrophones have been used by many countries as key R&D investment in national defense technology equipment.

The fiber grating sensor realizes the sensing function by using the optical waveguide characteristics of the optical fiber and the grating to reflect specific wavelengths and has the modulation effect of sensing specific parameters in the environment. sound signal. Compared with traditional piezoelectric hydrophones, fiber-optic hydrophones mainly have the following advantages: wide frequency band, high sensitivity, no electromagnetic interference, small mass, small volume and simple structure, combined with fiber-optic light source and fiber-optic spectrometer, can be integrated It has great application prospects.

At present, improving the pressure sensitivity of FBG hydrophones, using filtering structure to constrain the working frequency range of FBG hydrophones, and improving the structure to adapt to specific applications are the current development directions of FBG hydrophones. How to solve the problem of large acceleration response and high low-frequency noise is an important technical problem in the current fiber optic hydrophone, which needs to be further explored and improved.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to increase the reliability and stability of the fiber grating hydrophone during operation by introducing the cymbal-shaped diaphragm and the way that the diaphragm is fixedly connected to the main structure, so as to solve the problem of using a piston-type flat-shaped diaphragm in the prior art. During the working process of the diaphragm fiber grating hydrophone, the sealing structure will fail due to the relative movement of the diaphragm and the structure, the relative movement will lead to wear, the life of the structure will be reduced, and the sensitivity to the feedback of the underwater acoustic signal will eventually be insufficient.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is:

The outer side of the supporting cylinder (7) is covered with a sound-transmitting rubber sleeve (3), the two sides of the supporting cylinder (7) are respectively fixed to the left casing (1) and the right casing (5), and the supporting cylinder (7) is symmetrically fixed inside The left cymbal-shaped diaphragm (201) and the right cymbal-shaped diaphragm (401) are provided with a left copper plate (202) and a right copper plate (402) for fixing the fiber grating (6), the fiber grating (6) Pass through the hole on the central axis of the hydrophone; the gap between the fiber grating (6) and the contact position of the hydrophone is filled with sealing material; the left casing (1) and the supporting cylinder (7) and the left cymbal diaphragm (201) ) to form a closed cavity; the right casing (5), the supporting cylinder (7) and the right cymbal-shaped diaphragm (401) form a closed cavity; the left cymbal-shaped diaphragm (201), the right cymbal-shaped diaphragm (401), The support cylinder (7) and the sound-transmitting rubber sleeve (3) form an oil cavity, which is filled with oil; the middle of the support cylinder (7) has holes on the upper and lower sides for transmitting the sound pressure in the water.

The advantages of the invention are: the cymbal-shaped diaphragm is used to convert the volume change of the oil cavity caused by the sound pressure into the length change of the fiber grating, and the structure is simple. The way of fixing the support cylinder increases the reliability and stability of the structure.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Fig. 2 is a side sectional view of the central axis of the present invention.

Detailed ways

1 and 2, the present embodiment will be described in detail. In the fiber grating hydrophone using double cymbal diaphragms described in this embodiment, the outer side of the support cylinder 7 is covered with a sound-transmitting rubber sleeve 3, and the support cylinder 7 The left casing 1 and the right casing 5 are respectively fixed on both sides, and the left cymbal-shaped diaphragm 201 and the right cymbal-shaped diaphragm 401 are symmetrically and fixedly installed inside the supporting cylinder 7, and the left copper sheet 202 and the right copper sheet 402 are installed on the diaphragm. For fixing the fiber grating 6, the fiber grating 6 passes through the hole on the central axis of the hydrophone; the gap between the fiber grating 6 and the hydrophone contact position is filled with sealing material; the left casing 1 and the supporting cylinder 7 and the left cymbal-shaped membrane The sheet 201 forms a closed cavity; the right casing 5, the supporting cylinder 7 and the right cymbal-shaped diaphragm 401 form a closed cavity; the left cymbal-shaped diaphragm 201, the right cymbal-shaped diaphragm 401, the supporting cylinder 7 and the sound-transmitting rubber sleeve 3. An oil cavity is formed, and the interior is filled with oil; there are holes on the upper and lower sides of the middle of the support cylinder 7, which are used to transmit the sound pressure in the water.

The working principle of the fiber grating hydrophone in the present invention is as follows: when the hydrophone receives the sound pressure of water underwater, the sound pressure will act on the oil in the oil cavity through the sound-transmitting rubber sleeve 3, and the oil will be absorbed by the water. Squeeze and transmit the pressure to the left cymbal diaphragm 201 and the right cymbal diaphragm 401 fixed on the support cylinder 7, the left cymbal diaphragm 201 and the right cymbal diaphragm 401 undergo axial deformation, and The deformation is transmitted to the fiber grating 6 fixed between the left copper sheet 202 and the right copper sheet 402. When the fiber grating 6 is deformed axially, the wavelength of the reflected light will change. By measuring the reflected light in the fiber grating 6 The corresponding underwater acoustic information can be obtained.

Claims (1)

1. A fiber grating hydrophone using a double cymbal-shaped diaphragm, comprising: a left housing (1), a left cymbal-shaped diaphragm (201), a left copper sheet (202), a sound-transmitting rubber sleeve (3), The right cymbal-shaped diaphragm (401), the right copper sheet (402), the right casing (5), the optical fiber grating (6), and the supporting cylinder (7) are characterized in that: the outer side of the supporting cylinder (7) is covered with sound-transmitting The rubber sleeve (3), the left casing (1) and the right casing (5) are respectively fixed on both sides of the supporting cylinder (7), and the left cymbal diaphragm (201) and the right cymbal are fixed symmetrically inside the supporting cylinder (7). a diaphragm (401), a left copper sheet (202) and a right copper sheet (402) are installed on the diaphragm for fixing the fiber grating (6), and the fiber grating (6) passes through the hole on the central axis of the hydrophone; The gap between the fiber grating (6) and the hydrophone is filled with sealing material; the left casing (1) forms a closed cavity with the supporting cylinder (7) and the left cymbal diaphragm (201); the right casing (5) A closed cavity is formed with the supporting cylinder (7) and the right cymbal-shaped diaphragm (401); the left cymbal-shaped diaphragm (201), the right cymbal-shaped diaphragm (401), the supporting cylinder (7) and the sound-transmitting rubber sleeve (3) An oil cavity is formed, and the inside is filled with oil; there are holes on the upper and lower sides of the middle of the support cylinder (7), which are used to transmit the sound pressure in the water.

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