CN-114812783-B - Low-frequency sinusoidal vibration mechanism

CN114812783BCN 114812783 BCN114812783 BCN 114812783BCN-114812783-B

Abstract

The invention relates to the technical field of hydrophone measurement and calibration, in particular to a low-frequency sinusoidal vibration mechanism which comprises a fixed frame, a driving mechanism, a guide mechanism and an open container, wherein the driving mechanism is arranged on the fixed frame and comprises a motor, a speed reducer and a swinging mechanism, the motor and the speed reducer are respectively arranged on the fixed frame, a rotating shaft of the motor is connected with an axial input end of the speed reducer, a rotating shaft of the swinging mechanism is connected with an axial output end of the speed reducer, the guide mechanism is arranged on the fixed frame, a movable end of the guide mechanism is connected with a reciprocating swinging end of the swinging mechanism, the open container is vertically arranged on the fixed frame, the lower end of the open container is matched with the movable end of the guide mechanism, and the open end of the open container is upwards arranged.

Inventors

ZHU XUEWEN
XU ZHUOHUA

Assignees

中国船舶重工集团公司第七一五研究所
中国船舶重工集团公司第七一五研究所

Dates

Publication Date: 20260421
Application Date: 20220308
Priority Date: 20220308

Claims (8)

1. The low-frequency sinusoidal vibration mechanism is characterized by comprising a fixed frame, a driving mechanism, a guide mechanism and an opening container, wherein the driving mechanism, the guide mechanism and the opening container are arranged on the fixed frame, the driving mechanism comprises a motor, a speed reducer and a swinging mechanism, the motor and the speed reducer are respectively arranged on the fixed frame, a rotating shaft of the motor is connected with an shaft input end of the speed reducer, a rotating shaft of the swinging mechanism is connected with an shaft output end of the speed reducer, the guide mechanism is arranged on the fixed frame, a movable end of the guide mechanism is connected with a reciprocating swinging end of the swinging mechanism, the opening container is vertically arranged on the fixed frame, the lower end of the opening container is matched with the movable end of the guide mechanism, the opening end of the opening container is upwards arranged, the swinging mechanism comprises a cam disc, a connecting rod, an upper shaft and a lower shaft, the center of the cam disc is connected with the shaft output end of the speed reducer, the cam disc is provided with a shaft hole, one end of the connecting rod is rotatably arranged in the shaft hole, the other end of the connecting rod is rotatably connected with the upper shaft, the upper shaft is matched with the movable end of the guide mechanism, and the guide mechanism is a guide assembly.
2. The low-frequency sinusoidal vibration mechanism of claim 1, wherein the upper shaft is provided with a joint connector in a matched manner, and one end of the joint connector away from the upper shaft is connected with a reciprocating telescopic end of the needle roller guide assembly through a joint nut.
3. The low-frequency sinusoidal vibration mechanism of claim 2, wherein a sleeve is arranged on the fixed frame corresponding to the open container, a locking screw is arranged on the sleeve, the lower end of the open container is matched and butted with the sleeve, and the locking screw is tightly matched with the lower end of the open container.
4. The low-frequency sinusoidal vibration mechanism as set forth in claim 3, wherein the sleeve is fixed to the upper end of the reciprocating telescoping end of the needle guide assembly.
5. The low-frequency sinusoidal vibration mechanism as recited in claim 1, wherein the cam plate is provided with a plurality of shaft holes having different pitches from the center of the plate.
6. The low-frequency sinusoidal vibration mechanism of claim 1, wherein the motor is a stepper motor.
7. The low-frequency sinusoidal vibration mechanism of claim 1, wherein the speed reducer is a planetary gear speed reducer.
8. A low frequency sinusoidal vibration mechanism as claimed in claim 1, wherein the side wall of the open vessel is provided with through holes.

Description

Low-frequency sinusoidal vibration mechanism Technical Field The invention relates to the technical field of hydrophone measurement and calibration, in particular to a low-frequency sinusoidal vibration mechanism. Background In the ocean, various acoustic waves with different frequencies are propagated from different natural acoustic sources. In addition to high acoustic frequency, low acoustic frequency underwater sounds caused by stormy waves, traffic, aquatic organisms, etc., there are ultra-low frequency (also called low-order acoustic frequency) underwater sounds caused by ocean movements, earthquakes, etc., the frequency of which is as low as below 0.1 Hz. In order to explore, develop the ocean and study the climate through the study of acoustic wave characteristics in the ocean or the utilization of acoustic wave propagation characteristics in the ocean, detection of acoustic signals in the ocean must be performed. To ensure accurate and effective detection, acoustic measurement devices such as hydrophones should be calibrated in advance. At present, national standard of underwater sound pressure and national standard and national defense in the frequency range of 1 Hz-5 MHz are established in China, but the standard or standard of the underwater sound pressure below 1Hz is also lacking. In addition, the ultra-low frequency underwater sound pressure standard is also needed for the research of the water pressure field in the physical field utilized by the underwater detonator and the research of corresponding detonator equipment. Therefore, the research and establishment of the ultra-low frequency underwater sound pressure standard lower than 1Hz has important practical significance in the requirements of scientific research and national economy construction or national defense construction. Because the vibration amplitude of the sound source required for generating the measurable sound pressure in the ultra-low frequency band is quite large, the ultra-low frequency signal in water is very difficult to generate by adopting a common method in the calibration of the ultra-low frequency hydrophone. Even if the electrodynamic compensation calibration method is applied, the lowest available frequency is typically 0.1Hz, and if the piezoelectric compensation calibration method is applied, the frequency is higher, typically not lower than 1Hz. The ultra-low frequency underwater sound wave with the characteristics of long wavelength and large vibration amplitude acting on the hydrophone in ultra-low frequency calibration is very suitable for simulation generation by applying periodically-changing hydrostatic pressure. This alternating hydrostatic pressure is obtained by periodically varying the depth of the hydrophone below the free water surface and is therefore relatively easy to achieve. The ultra-low frequency underwater sound pressure field generation schematic diagram is shown in fig. 1, and the measuring water cavity is a fixed container filled with water. The hydrophone to be measured is fixedly arranged in the measuring water cavity. The measuring water chamber is provided with a thin neck. The water in the cavity is connected with the water in an opening container at the upper part through the neck pipe. The open container moves vertically and periodically at very low frequency (displacement d=d0cos ωt, displacement amplitude d 0), under the condition of neglecting the inertial force of the moving water body, the hydrostatic pressure (amplitude) generated in the water cavity is measured to be p=ρgd 0, and the alternating hydrostatic pressure meeting the measurement requirement can be obtained. From the above description, to obtain the alternating hydrostatic pressure, a set of low-frequency sinusoidal vibration mechanism needs to be designed to drive the open container to perform vertical periodic motion. Disclosure of Invention Aiming at the defects existing in the prior art, the invention aims to provide a low-frequency sinusoidal vibration mechanism which is used for accurately calibrating the sound pressure sensitivity of a hydrophone in an ultralow frequency range. The low-frequency sinusoidal vibration mechanism comprises a fixed frame, a driving mechanism, a guide mechanism and an opening container, wherein the driving mechanism is arranged on the fixed frame, the driving mechanism comprises a motor, a speed reducer and a swinging mechanism, the motor and the speed reducer are respectively arranged on the fixed frame, a rotating shaft of the motor is connected with an shaft input end of the speed reducer, a rotating shaft of the swinging mechanism is connected with an shaft output end of the speed reducer, the guide mechanism is arranged on the fixed frame, a movable end of the guide mechanism is connected with a reciprocating swinging end of the swinging mechanism, the opening container is vertically arranged on the fixed frame, the lower end of the opening container is matched with the mova