Hydrophone equivalent self-noise testing device

Abstract

The invention relates to a hydrophone equivalent self-noise testing device which comprises a support, the support is composed of a base and an inverted-U-shaped hanging bracket, the base is a cube frame, the inverted-U-shaped hanging bracket is fixed over the base, and a hand-cranking hoist is installed on the inverted-U-shaped hanging bracket; the shell is of a cylindrical structure with an opening in the upper end, and the shell is arranged on the base; the four damping assemblies are arranged at the four corners of the top of the cube frame correspondingly and used for vibration isolation of the shell and the support, and the lower ends of the damping assemblies are connected with the top of the cube frame; the cover plate is provided with a round hole matched with the shell, the upper end of the shell penetrates through the round hole, and the cover plate is fixedly connected with the upper end of the damping assembly. According to the invention, the reliability and convenience of the equivalent self-noise test of the hydrophone are effectively improved, the test process is more stable, and the result is more accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrophones and relates to a hydrophone equivalent self-noise testing device. Background Art

[0002] As a key unit for picking up underwater acoustic signals, the development of hydrophone technology is of great significance to the overall performance improvement of sonar systems. The equivalent self-noise of the hydrophone is the main source of system noise. Accurately measuring the equivalent self-noise of the hydrophone is crucial to the performance characterization of the hydrophone. In order to ensure the accuracy of the hydrophone self-noise test, the key is that the test device can effectively isolate the influence of sound, vibration and electromagnetic interference in the external environment, especially the influence of low-frequency sound and vibration. The existing scheme places the hydrophone in a closed metal cavity, and installs a sound-absorbing structure and a vibration-reducing structure in the metal cavity to isolate the influence of external sound, vibration and electromagnetic interference. This type of device cannot completely isolate the influence of low-frequency sound and vibration (below 100Hz) on the hydrophone noise test, so there is a certain error in the characterization of the low-frequency self-noise of the hydrophone. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a hydrophone equivalent self-noise test device. On the basis of isolating electromagnetic interference, the device is designed with a multi-stage vibration reduction and isolation structure to isolate the interference of low-frequency vibration, and is designed with a vacuum unit to generate a vacuum test environment to isolate acoustic interference. Through the design of the device, the reliability and convenience of the hydrophone equivalent self-noise test are effectively improved, making the test process more stable and the results more accurate.

[0004] The technical solution of the present invention is to provide a hydrophone equivalent self-noise test device, comprising: The bracket is composed of a base and an inverted U-shaped hanger. The base is a cube frame. The inverted U-shaped hanger is fixed directly above the base. A hand-cranked hoist is installed on the inverted U-shaped hanger. The shell is a cylindrical structure with an open upper end, and the shell is placed on the base; Shock-absorbing components, there are four shock-absorbing components, which are respectively arranged at the four corners of the top of the cube frame, and are used for vibration isolation between the shell and the bracket. The lower end of the shock-absorbing component is connected to the top of the cube frame; A cover plate, wherein the cover plate is provided with a circular hole adapted to the shell, the upper end of the shell passes through the circular hole, and the cover plate is fixedly connected to the upper end of the shock absorbing assembly; An end cover is arranged at the upper end of the shell, a plug-in connector is arranged on the end cover, the plug-in connector runs through the end cover, a handle is arranged on the upper surface of the end cover, and the handle is connected to the hand-cranked hoist through a pull rope; A hydrophone is arranged in the housing and is suspended below the end cover through an elastic rope, and a power line and a signal output line of the hydrophone are connected to an external signal acquisition system through a connector; A vacuum pump is connected to the shell through an air pipe, and an air valve is arranged on the air pipe.

[0005] The present invention optimizes the equivalent self-noise test device of the hydrophone in the low frequency band, and effectively improves the reliability and convenience of the equivalent self-noise test of the hydrophone through reasonable thin air sound insulation design, multi-stage vibration reduction and isolation structure design and electromagnetic shielding design.

[0006] Preferably, the shock absorbing component is a single-bag shock absorbing air cushion or a spring shock absorber, which uses an air or spring shock absorbing structure inside.

[0007] Preferably, the shock absorbing assembly is connected to the cover plate by bolts, and the bolted joints are sealed with sealant.

[0008] Preferably, the shell is made of copper or stainless steel, and a round tube structure that can be connected to the air valve is protruded outward on one side of the shell, and the round tube structure is connected to the inner cavity of the shell.

[0009] Preferably, the end cover is made of copper or stainless steel, a groove is left at the lower side of the end cover, and a sealing ring is embedded in the groove.

[0010] Preferably, the cover plate is made of copper or stainless steel, and the four corners of the cover plate are respectively connected to the shock absorbing assembly by bolts.

[0011] Furthermore, the front cover plate is made of titanium alloy, the rear cover plate is made of copper alloy, and the prestressed rod and nut are made of No. 45 steel.

[0012] Furthermore, it also includes a cushion block, which is any one of an air cushion, a plurality of spring shock-absorbing pads and a silicone cushion. The cushion block is placed at the bottom of the vacuum pump to buffer the vibration interference transmitted through the vacuum pump.

[0013] Compared with the prior art, the present invention has the following advantages: The present invention effectively avoids the influence of low-frequency (below 100 Hz) sound and vibration on the hydrophone noise test through reasonable structural design, thereby making the test process more stable and the result more accurate; on the basis of isolating electromagnetic interference, the present invention designs a multi-stage vibration reduction and isolation structure to isolate the interference of low-frequency vibration, and designs a vacuum unit to generate a vacuum test environment to isolate acoustic interference. Through the design of the device, the reliability and convenience of the hydrophone equivalent self-noise test are effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention.

[0015] Figure 2 It is a schematic diagram of the local structure of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings: The present invention provides a hydrophone equivalent self-noise test device, such as Figure 1 , 2 As shown, it mainly includes a bracket 1, a shock absorbing component 2, a shell 3, an end cover 4, a vacuum pump 5, an air pipe 6, a hand-cranked hoist 7, a cover plate 8, an air valve 9, a hydrophone 10, a connector 11 and an elastic rope 13.

[0017] The bracket 1 is made of multiple sections of European standard 80mm*80mm*3mm aluminum alloy profiles of different lengths, and is mainly composed of a 680mm*680mm cube frame at the bottom and a 1500mm*840mm inverted U-shaped hanger, the two parts are fixed by angle brackets. Four shock absorbing components 2 are fixed on the four corners of the top of the cube frame, and a hook is provided on the inverted U-shaped hanger for installing a hand hoist 7.

[0018] In this embodiment, the shock absorbing component 2 is a single-bag shock absorbing air cushion or a spring shock absorber, which adopts an air or spring vibration reduction structure inside and is used for vibration isolation between the shell 3 and the bracket 1. The lower end of the shock absorbing component 2 is connected to the top of the cube frame; the shell 3 is a cylindrical structure with an open upper end, and the shell 3 is placed in the cube frame.

[0019] The cover plate 8 is provided with a circular hole adapted to the housing 3, the upper end of the housing 3 is arranged in the circular hole, and the cover plate 8 is fixedly connected to the upper end of the shock absorbing component 2. In this embodiment, the shock absorbing component 2 is an airbag, and four airbags are placed at the four corners of the bracket 1 and the cover plate 8, and the airbags and the cover plate 8 are connected by bolts, and the bolt connection is sealed with a sealant.

[0020] In this embodiment, the housing 3 is made of copper, stainless steel and other materials, which can ensure good electromagnetic shielding effect and good strength. The outer diameter of the top of the housing 3 is 480 mm, and is placed in the circular hole of the cover plate 8.

[0021] As an implementation mode, the cover plate 8 is made of copper, stainless steel, etc. The middle circular hole is used to place the housing 3; the four corners of the cover plate 8 are respectively rigidly connected to the four airbags by bolts.

[0022] As an embodiment, the end cover 4 is made of copper, stainless steel and other materials. The outer diameter of the upper side of the end cover 4 is 480mm, the outer diameter of the lower side is 450mm, and a groove is left on the lower side to embed a Φ433mm×7mm sealing ring; a round hole with a diameter of Φ16.5mm is left on the surface of the end cover 4 to place the connector 11; and two handles with a diameter of Φ10mm are welded on the surface of the end cover 4, which are connected to the hand-cranked hoist 7 by a thin rope, and the height of the end cover 4 is adjusted by the hand-cranked hoist 7.

[0023] In this embodiment, the hydrophone 10 adopts a compact structure of a sensor element and a preamplifier circuit, and a power line and a signal output line are connected to a signal acquisition system through a connector 11 .

[0024] The elastic rope 13 is made of a rubber band or a flexible spring and is used to elastically suspend the hydrophone 10 to further isolate the interference of vibration.

[0025] As an implementation method, the vacuum pump 5 is connected to the inner cavity 3 of the shell through the air pipe 6, and the air valve 9 is provided on the air pipe 6. Correspondingly, the shell 3 has a round tube structure with a length of 50 mm, an inner diameter of 25 mm, and an outer side of a 1.2-inch threaded tube, which is connected to the air valve 9. In this way, the vacuum pump 5 is connected to the air pipe 6, and by running the vacuum pump 5 and then closing the air valve 9, it is ensured that the shell 3 is in a near vacuum environment during the experiment, isolating the interference caused by external noise.

[0026] The present invention further includes a cushion block 12 , which is any one of an air cushion, a plurality of spring shock-absorbing cushions and a silicone cushion. The cushion block 12 is placed at the bottom of the vacuum pump 5 to buffer the vibration interference transmitted by the vacuum pump 5 .

[0027] The hydrophone equivalent self-noise test device designed by the present invention can effectively isolate low-frequency sound interference by creating a vacuum environment for sound insulation. The sound insulation means are more thorough and can take into account the needs of wide-band hydrophone noise testing. Vibration isolation of the entire device can be achieved through multiple, multi-stage vibration reduction and isolation methods such as air bags, elastic ropes, and elastic air cushions. At the same time, the design of the metal shell takes into account the function of electromagnetic shielding. This design device reduces the impact of differences in test environments and improves test consistency.

[0028] The above is only an explanation of the preferred embodiments of the present invention, which should not be construed as a limitation on the claims. Any equivalent process changes made using the present invention specification are included in the patent protection scope of the present invention.

Claims

1. A hydrophone equivalent self-noise test device, characterized in that: include: The bracket is composed of a base and an inverted U-shaped hanger. The base is a cube frame. The inverted U-shaped hanger is fixed directly above the base. A hand-cranked hoist is installed on the inverted U-shaped hanger. The shell is a cylindrical structure with an open upper end, and the shell is placed on the base; Shock-absorbing components, there are four shock-absorbing components, which are respectively arranged at the four corners of the top of the cube frame, and are used for vibration isolation between the shell and the bracket. The lower end of the shock-absorbing component is connected to the top of the cube frame; A cover plate, the cover plate is provided with a circular hole adapted to the shell, the upper end of the shell passes through the circular hole from bottom to top, and the cover plate is fixedly connected to the upper end of the shock absorbing assembly; An end cover is arranged at the upper end of the shell, a plug-in connector is arranged on the end cover, the plug-in connector runs through the end cover, a handle is arranged on the upper surface of the end cover, and the handle is connected to the hand-cranked hoist through a pull rope; A hydrophone, which is arranged in the housing and suspended below the end cover through an elastic rope, and a power line and a signal output line of the hydrophone are connected to an external signal acquisition system through a connector; A vacuum pump is connected to the shell through an air pipe, and an air valve is arranged on the air pipe.

2. The hydrophone equivalent self-noise test device according to claim 1, characterized in that: The base and the inverted U-shaped hanger are made of aluminum alloy profiles and are connected and fixed by angle brackets.

3. The hydrophone equivalent self-noise test device according to claim 1, characterized in that: The shock absorbing component is a single-bag shock absorbing air cushion or a spring shock absorber.

4. The hydrophone equivalent self-noise test device according to claim 1, characterized in that: The shock-absorbing assembly is connected to the cover plate by bolts, and the bolt joints are sealed with sealant.

5. The hydrophone equivalent self-noise test device according to claim 1, characterized in that: The shell is made of copper or stainless steel. A round tube structure which can be connected to the air valve is protruded outward on one side of the shell. The round tube structure is connected to the inner cavity of the shell.

6. The hydrophone equivalent self-noise test device according to claim 5, characterized in that: The end cover is made of copper or stainless steel, and a groove is left at the lower side of the end cover, in which a sealing ring is embedded.

7. The hydrophone equivalent self-noise test device according to claim 1, characterized in that: The cover plate is made of copper or stainless steel, and the four corners of the cover plate are respectively connected to the shock absorbing components by bolts.

8. The hydrophone equivalent self-noise test device according to claim 1, characterized in that: It also includes a pad, which is any one of an air cushion, a plurality of spring shock-absorbing pads and a silicone cushion. The pad is placed at the bottom of the vacuum pump to buffer the vibration interference transmitted through the vacuum pump.

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