Hydrophone noise suppression module

Abstract

The utility model belongs to the technical field of vibration and noise reduction, and relates to an external interference noise suppression module integrated in a hydrophone. The module comprises a high-characteristic-impedance metal round rod and two low-characteristic-impedance rubber round rods, the rubber round rods are connected to the two ends of the metal round rod, the cross sectional areas of the metal round rod and the rubber round rods for transmitting interference elastic waves are the same, and the lengths of the two rubber round rods are different, so that half-wavelength total transmission is restrained. The interference longitudinal wave passes through the noise suppression module, most energy is lost, and the interference noise is effectively suppressed. The utility model has the effects and benefits that the external interference noise is reduced, and the anti-interference level of the hydrophone is improved. The device is widely applied to noise suppression design of the hydrophone, is simple in structure, is convenient to integrate in the hydrophone, and can stably work in seawater for a long time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vibration and noise reduction, and relates to a noise suppression module integrated in a hydrophone. BACKGROUND

[0002] The hydrophone is usually installed on the hull shell or laid in the sea at a certain depth, and is disturbed by the vibration of the ship body and the noise of the marine environment. In order to reduce the influence of external interference on the measured target, the hydrophone is usually installed with vibration isolation rubber, and the vibration reduction effect needs to be improved. SUMMARY

[0003] The purpose of the present application is to provide a noise suppression module with reduced external interference. The module is integrated inside the hydrophone, placed between the piezoelectric conversion module and the amplification circuit module of the hydrophone, and used to solve the problem of measurement accuracy affected by external interference noise.

[0004] The technical solution of the present application is a noise suppression module, which comprises a metal round rod and a rubber round rod. The rubber round rod is divided into two segments of different lengths and is connected to the two ends of the metal round rod. The metal round rod and the rubber round rod are connected by threads.

[0005] First, the piezoelectric conversion module is connected to the noise suppression module by threads, then the noise suppression module and the metal electronic cabin are connected by threads, and finally the hydrophone is packaged by vulcanization. The interference noise is transmitted in the form of elastic waves to the metal electronic cabin. Since the characteristic impedance of metal is much larger than that of rubber, most of the energy is reflected at the interface between the metal electronic cabin and the rubber round rod of the noise suppression module. A small part of the transmitted energy is reflected again at the interface between the rubber round rod and the metal round rod of the noise suppression module, and the interference longitudinal wave is finally reflected at the interface between the metal round rod and the rubber round rod of the noise suppression module. In this way, after three reflections, only a small part of the interference energy in the elastic longitudinal wave is transmitted to the piezoelectric conversion module, which is close to the absolute soft boundary reflection effect, and the interference noise is effectively suppressed. The elastic transverse wave in the interference noise is reflected or transmitted by the noise suppression module, and does not form interference noise. The two segments of the rubber round rod in the noise suppression module are of different lengths and can suppress half-wave transmission.

[0006] The effect and benefit of the present application is to reduce external interference noise and improve the anti-interference level of the hydrophone. The present application is widely used in the noise suppression design of hydrophones and other water acoustic tests that require vibration reduction. The structure is simple and easy to integrate inside the hydrophone, and can work stably in seawater for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 The structure of the noise suppression module before vulcanization packaging.

[0008] Figure 2 The schematic diagram of the hydrophone structure before vulcanization packaging.

[0009] Figure 3 The schematic diagram of the hydrophone structure after vulcanization packaging.

[0010] Figure 4 The schematic diagram of the interference longitudinal wave reflection and transmission

[0011] In the figure: 1 rubber round rod, 2 metal round rod, 3 rubber round rod, 4 pre-packaging piezoelectric conversion module, 5 pre-packaging noise suppression module, 6 pre-packaging electronic cabin module, 7 post-packaging piezoelectric conversion module, 8 post-packaging noise suppression module, 9 post-packaging electronic cabin module, 10 electronic cabin module and noise suppression module interface, 11 rubber round rod and metal round rod interface, 12 metal round rod and rubber round rod interface, 13 incident interference longitudinal wave Pi, 14 reflected interference longitudinal wave Pr, 15 refracted interference longitudinal wave Pt. DETAILED DESCRIPTION

[0012] The specific embodiment of the present application will be described in detail below in combination with the technical solutions and the drawings.

[0013] The specific embodiment of the present application is as follows:

[0014] Reference Figure 1 , first, the metal round rod 2 and the rubber round rod 1, 3 are connected by threads, reference Figure 2 , the noise suppression module 5 and the piezoelectric conversion module 4, the electronic cabin module 6 are connected by threads, and finally the water-tight vulcanization packaging is completed as shown in Figure 3 . The disturbance elastic longitudinal wave is transmitted to the post-packaging noise suppression module 8 through the post-packaging metal electronic cabin 9 module. Since the characteristic impedance of the metal is much larger than that of the rubber, most of the energy of the elastic longitudinal wave is reflected at the interface 10 between the electronic cabin module 9 and the noise suppression module 8, and a small part of the energy is transmitted. The elastic longitudinal wave is reflected again at the interface 11, 12 between the post-packaging rubber round rod and the metal round rod, and a very small part of the energy is transmitted to the piezoelectric conversion module 7, greatly suppressing the external interference noise. In this example, the piezoelectric conversion module adopts spherical piezoelectric ceramic, the noise suppression module rubber round rod adopts chloroprene rubber with a hardness of Shore 62°, and the metal round rod and the electronic cabin module are made of 316 stainless steel due to its high characteristic impedance and resistance to seawater corrosion. The metal round rod has a size of φ22*20, the rubber round rod has a size of φ18*8, φ18*10, the metal electronic cabin round tube has a size of φ22*φ16*80, the outer diameters of the modules after vulcanization packaging are the same, and the materials are corrosion-resistant, so that the hydrophone can work stably in the marine environment.

Claims

1. A hydrophone noise suppression module, characterized by: The noise suppression module comprises a high characteristic impedance metal round rod and two low characteristic impedance rubber round rods, the rubber round rods are connected to two ends of the metal round rod, the metal round rod and the rubber round rods for transmitting interference elastic waves have the same cross-sectional area, and the two rubber round rods have different lengths to suppress half-wavelength full transmission.

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