Liquid-filled tube planar sound source

Abstract

This invention discloses a planar sound source with a liquid-filled pipeline, solving the problems of large size, complex operation, poor adaptability, and insufficient low-frequency sound radiation effect in existing structures. The technical solution includes a sound source housing and a piston disposed within the housing. A pressure-regulating cavity is formed between the inner surface of the piston and the housing. A piston rod passes through the housing and connects to a piezoelectric actuator. The pressure-regulating cavity is connected to the measurement environment via a microchannel on the housing, and a shut-off valve is provided on the microchannel. This invention features a simple structure, small size, extremely simple operation, automatic balancing of fluid pressure on both sides of the piston, good low-frequency sound radiation effect, and effectively improved sound radiation efficiency of the piston.

Description

Technical Field

[0001] This invention relates to the field of pipeline acoustic testing, specifically a planar sound source for a liquid-filled pipeline. Background Technology

[0002] Acoustic methods are the main means in many fields such as underwater detection, measurement, target identification and positioning, and marine geological exploration. In underwater acoustic pipeline experiments, very low frequency and wide frequency band sound sources are needed as test sound sources to measure and calibrate the performance of pipeline components and underwater acoustic materials.

[0003] Existing technologies include electroelectric and piezoelectric transducers. Electroelectric transducers used underwater generally consist of a vibrating component, a permanent magnet component, a pressure compensation structure, and a sealing structure, with an air-filled internal cavity. Their working principle involves subjecting a coil placed in a permanent magnetic field to a magnetic driving force. This force propels the coil in a piston-like motion, which in turn moves a radiation cover plate connected to the coil, thus radiating sound waves into the water. To meet radiation intensity requirements and improve low-frequency sound radiation effects, electroelectric transducers are typically relatively large. To balance the fluid pressure on both sides of the piston, the pressure inside the piston cavity must be adjusted. Current electroelectric transducers generally store a certain amount of air or oil, using the volume of compressed gas or oil to ensure that the internal pressure matches the external water pressure, thereby achieving balance at different water depths.

[0004] CN102075828A discloses an underwater electric transducer, which consists of a transducer shell, a vibration assembly, a guide assembly, a support and sealing assembly, a magnetic circuit assembly, and a sealing and electrical interface, enabling underwater low-frequency acoustic radiation. This invention uses a magnetic circuit assembly to divide the inflatable airbag into two cavities, front and rear. The transducer needs to be completely submerged in water for pressure compensation. Due to its large size, this invention is unsuitable for use in pipeline experiments.

[0005] CN201310071343 discloses an electric underwater acoustic transmitter transducer. This invention adjusts the pressure inside the air spring cavity by relying on an external inflation device based on the output signal of a displacement sensor to achieve pressure balance on both sides of the piston. The force of this system is affected by factors such as coils and magnetic poles, resulting in a large structural size and a relatively complex pressure adjustment process.

[0006] CN204231638U discloses a water acoustic piezoelectric transducer, which uses sealing rubber to cover the piezoelectric ceramic tube, electrode socket and support components and vulcanizes them together. Since the sound source is completely immersed in the liquid, its low-frequency sound radiation effect is poor and cannot meet the acoustic testing requirements in the pipeline. Summary of the Invention

[0007] The purpose of this invention is to solve the above-mentioned technical problems and provide a liquid-filled pipeline planar sound source that is simple in structure, small in size, extremely easy to operate, can automatically balance the fluid pressure on both sides of the piston, has good low-frequency sound radiation effect, and effectively improves the sound radiation efficiency of the piston.

[0008] The technical solution includes a sound source housing and a piston disposed within the sound source housing. A pressure-regulating cavity is formed between the inner surface of the piston and the sound source housing. The piston rod passes through the sound source housing and connects to a piezoelectric actuator. The pressure-regulating cavity is connected to the measurement environment via a microchannel on the sound source housing, and a shut-off valve is provided on the microchannel. The pressure-regulating cavity is also connected to an accumulator via a pipeline.

[0009] The piezoelectric actuator is fixed to the sound source housing by a bracket.

[0010] The pressure regulating cavity is connected to the measurement environment in the direction of the piston's radiating surface via a microchannel.

[0011] The diameter of the microchannel is 0.5-1.5 mm.

[0012] The piston rod is threadedly connected to the piezoelectric actuator.

[0013] A pressure gauge is also installed on the pipe connecting the pressure regulating cavity and the accumulator.

[0014] To address the problems existing in the background technology, the inventors have made the following improvements:

[0015] 1) A microchannel is installed on the outer shell to connect the pressure regulating chamber and the experimental pipeline, thus forming a bypass controlled by a shut-off valve. Before measurement, the shut-off valve is opened to connect the bypass, allowing the pressure regulating chamber to be connected to the external measurement environment. External liquid enters the pressure regulating chamber through the microchannel, thereby satisfying the requirement of static water pressure balance on both sides of the piston. This structure, seemingly simple, is ingenious and effectively solves the problem of requiring external equipment to pressurize the pressure regulating chamber in existing technologies. It greatly simplifies operation, reduces operational difficulty and cost, and is suitable for water pressure balance at different water depths. It does not require repeated pressurization and meets the needs of continuous testing at different water depths.

[0016] 2) Due to the simplification of equipment and operation, the previous air filling of the pressure regulating cavity has been changed to liquid filling. With the use of a compact piezoelectric actuator, the entire equipment is small in size and has good sealing performance, which greatly increases its working depth.

[0017] 3) When using a microchannel to achieve static water pressure balance on both sides of the plug, the pressure regulating cavity will be filled with the same liquid as the measurement environment. Due to the poor compressibility of the liquid, the piston movement is hindered, resulting in low-frequency radiation efficiency, which cannot meet the requirements of low-frequency testing. Therefore, an accumulator is set in the pressure regulating cavity. The accumulator can effectively reduce the radiation impedance of the piston surface and effectively improve the sound radiation efficiency of the piston. It has good flexibility and adaptability, and can obtain a wider operating frequency range and pressure range without the need for an additional air source or pressure regulating device.

[0018] Beneficial effects

[0019] This invention has a simple structure, small size, and is easy to operate. It does not require an additional air source or pressure regulating device. It can automatically balance the fluid pressure on both sides of the piston, has good low-frequency sound radiation effect, and effectively improves the sound radiation efficiency of the piston. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] Among them, the sound source shell 1, piston 2, piston inner surface 2-1, piston outer surface 2-2, piston rod 2-3, microchannel 3, shut-off valve 4, pressure regulating cavity 5, piezoelectric actuator 6, bracket 7, accumulator 8, straight pipe 9, tee pipe 10, and pressure gauge 11. Detailed Implementation

[0022] The invention will be further explained below with reference to the accompanying drawings:

[0023] See Figure 1 The piston 2 is housed within the sound source housing 1. The outer surface 2-2 of the piston serves as the sound radiation surface, and the inner surface 2-1 of the piston forms a pressure regulating cavity 5 between it and the sound source housing 1. The piston rod 2-3 passes through the sound source housing 1 and is threadedly connected to a piezoelectric actuator 6, which is fixed to the sound source housing 1 by a bracket 7. The pressure regulating cavity 5 is connected to the measurement environment in the direction of the piston 2's radiation surface via a microchannel 3 on the sound source housing 1. The diameter of the microchannel 3 is preferably 0.5-1.5 mm, and a shut-off valve 4 is provided on the microchannel 3. The microchannel 3 is controlled by the shut-off valve 4 to close when the water pressure at both ends of the piston 2 reaches static equilibrium, thereby reducing sound leakage and improving the radiation effect. The pressure regulating cavity 5 is also connected to an accumulator 8 via a straight pipe 9 and to a pressure gauge 11 via a series three-way pipe 10. An O-ring seal is used between the piston 2 and the sound source housing 1; this is existing technology and will not be described in detail.

[0024] Before the invention is put into operation, the shut-off valve 4 is opened to connect the pressure regulating chamber 5 to the outside. The external liquid enters the pressure regulating chamber 5 through the microchannel 3. After the water pressure on both sides of the piston 2 is statically balanced, the shut-off valve is closed and the piezoelectric actuator 6 is started, so that the piston 2 generates longitudinal vibration. Different vibration modes of the piston are excited in different frequency ranges, thereby radiating planar sound waves into the filling pipeline.

[0025] The specific usage steps of this invention are as follows:

[0026] (1) Using the flange device on the sound source housing 1, install the present invention on the experimental pipeline and check the water tightness of the sealing interface;

[0027] (2) Open the shut-off valve 4 and add water and pressurize the experimental pipeline. When the pipeline pressure is the same as the pressure in the pressure regulating chamber 5, close the shut-off valve so that the radial surface of the piston 2 is in a balanced position.

[0028] (3) Turn on the piezoelectric actuator. After inputting the signal, the planar sound source in the filling pipeline will start working.

[0029] The performance metrics for this embodiment are as follows:

[0030] Operating frequency range: 10-2000Hz;

[0031] Working pressure range: 0-10 MPa;

[0032] For a DN100 pipeline, the dimensions are: sound source diameter 200mm, length 176mm, piston diameter 80mm, and micro-channel diameter 1mm.

Claims

1. A planar sound source with a liquid-filled pipeline, comprising a sound source housing and a piston disposed within the sound source housing, wherein a pressure-regulating cavity is formed between the inner surface of the piston and the sound source housing, and a piston rod passes through the sound source housing and is connected to a piezoelectric actuator, characterized in that, The pressure regulating cavity is connected to the measurement environment in the direction of the piston radiation surface via a microchannel on the sound source shell. A shut-off valve is provided on the microchannel. The pressure regulating cavity is also connected to the accumulator via a pipeline. Before measurement, open the shut-off valve to connect the pressure regulating chamber with the measurement environment. Liquid in the measurement environment enters the pressure regulating chamber through the microchannel. After the water pressure on both sides of the piston is statically balanced, close the shut-off valve and turn on the piezoelectric actuator.

2. The planar sound source for a liquid-filled pipeline as described in claim 1, characterized in that, The piezoelectric actuator is fixed to the sound source housing by a bracket.

3. The planar sound source for a liquid-filled pipeline as described in claim 1, characterized in that, The diameter of the microchannel is 0.5-1.5 mm.

4. The planar acoustic source for a liquid-filled pipeline as described in claim 1, characterized in that, The piston rod is threadedly connected to the piezoelectric actuator.

5. The planar acoustic source for a liquid-filled pipeline as described in claim 1, characterized in that, A pressure gauge is also installed on the pipe connecting the pressure regulating cavity and the accumulator.

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