Vibrating wire type accelerometer

Abstract

The utility model provides a vibrating wire type accelerometer which comprises a shell, a first limiting block and a second limiting block are arranged in the shell, a limiting slide way is formed between the first limiting block and the second limiting block, a sliding block is connected in the limiting slide way in a sliding mode, two clamping mechanisms located on the two opposite sides of the sliding block are arranged in the shell, and the two opposite side walls of the sliding block are connected with steel wires. The two steel strings are located on a sensitive shaft of the vibrating wire type accelerometer, the ends, opposite to the sliding block, of the two steel strings are detachably connected with clamping mechanisms, monitoring assemblies are arranged between the two clamping mechanisms and the sliding block and comprise supports connected to the bottom of the containing cavity, and excitation coils and induction coils are arranged at the tops of the supports. Electromagnetic attraction force is applied to the steel strings through the excitation coil, the steel strings generate vibration, vibration signals are collected through the induction coil, the acceleration can be obtained based on the vibration frequency difference between the vibration signals of the two steel strings, the whole structure is simple, in an unattended online low-frequency vibration monitoring scene, the manufacturing cost can be reduced, and the working efficiency is improved. The method is suitable for large-area popularization.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering measurement, in particular to a vibrating string accelerometer. Background Art

[0002] Low-frequency vibration refers to vibration with a frequency below 5Hz to 10Hz. It is often ignored because its vibration acceleration value is not large and has little impact on people's intuitive feelings. However, for large-scale engineering structures, low-frequency vibration cannot be ignored.

[0003] In the field of structural safety monitoring, active or passive servo-type accelerometers are often used to measure low-frequency vibrations of structures. These sensors are complex in structure and high in cost, and are mostly used in manual monitoring scenarios. That is, after the manual monitoring is completed, the equipment is recovered and reused in other projects.

[0004] However, in unmanned online monitoring scenarios, due to factors such as cost, active or passive servo accelerometers are difficult to promote and apply on a large scale. Utility Model Content

[0005] In view of the deficiencies in the prior art, the purpose of the present utility model is to provide a vibrating-string accelerometer, aiming to solve the technical problem in the prior art of lacking low-cost devices for monitoring low-frequency vibrations suitable for large-scale promotion in unmanned online low-frequency vibration monitoring scenarios.

[0006] In order to achieve the above purpose, the utility model is implemented through the following technical solutions:

[0007] A vibrating string accelerometer comprises a shell, wherein the shell is hollow inside to form a receiving chamber, a first limit block and a second limit block are respectively arranged at the top and the bottom of the receiving chamber, a limit slide is formed between the first limit block and the second limit block, a slider is slidably connected in the limit slide, two clamping mechanisms are arranged at the bottom of the receiving chamber, the two clamping mechanisms are located on opposite sides of the slider, the opposite side walls of the slider are connected to steel strings, the two steel strings are located on the sensitive axis of the vibrating string accelerometer, the ends of the two steel strings facing away from the slider are detachably connected to the clamping mechanisms, the clamping mechanisms are used to clamp the steel strings and adjust the tension of the steel strings, a monitoring component is arranged between the two clamping mechanisms and the slider, the monitoring component comprises a bracket connected to the bottom of the receiving chamber, an excitation coil and an induction coil are arranged at the top of the bracket, the excitation coil and the induction coil both correspond to the positions of the steel string, the excitation coil is used to apply electromagnetic suction to the steel string to make the steel string vibrate, and the induction coil is used to collect the vibration signal of the steel string.

[0008] Compared with the prior art, the utility model has the following beneficial effects: since the steel string is located on the sensitive axis of the vibrating string accelerometer, when the vibrating string accelerometer is accelerated, one of the steel strings is compressed and the other steel string is pulled to form a differential structure, which can improve the sensitivity of the vibrating string accelerometer and improve the linear measurement range of the vibrating string accelerometer; by setting the clamping mechanism and the detachable connection between the clamping mechanism and the steel string, the tension of the steel string can be conveniently adjusted to ensure the accuracy of monitoring, and the steel string can be replaced separately and regularly to ensure the long-term stability of the vibrating string accelerometer; by applying electromagnetic suction to the steel string through the excitation coil, the steel string vibrates, and the vibration signal is collected through the induction coil, and based on the vibration frequency difference between the vibration signals of the two steel strings, the acceleration of the vibrating string accelerometer can be acquired; the overall structure of the vibrating string accelerometer is simple, and in the unattended online low-frequency vibration monitoring scenario, the manufacturing cost can be effectively reduced, and it is suitable for large-scale promotion.

[0009] Furthermore, the clamping mechanism includes a clamping table, a clamping groove is provided on the clamping table and passes through the clamping table, the clamping groove corresponds to the position of the slider, a bearing block is provided on the side of the clamping table facing away from the slider, an abutment block is provided on the side of the bearing block facing the clamping table, the abutment block is located in the clamping groove, the top of the clamping groove is vertically movably connected to the clamping block, a clamping space is formed between the clamping block and the abutment block, a string-drawing hole is provided on the bearing block and passes through the bearing block, the string-drawing hole is connected to the clamping space, and the string-drawing hole corresponds to the position of the steel string.

[0010] Furthermore, the top of the clamping platform is concave to form a screw hole connected to the clamping groove, and an adjusting screw is threaded in the screw hole, and one end of the adjusting screw is rotatably connected to the clamping block.

[0011] Furthermore, the vibrating string accelerometer also includes a microcontroller, the microcontroller is electrically connected to the excitation coil through a coil excitation module, the induction coil is electrically connected to a signal amplification module, the signal amplification module is electrically connected to a filtering module, the filtering module is electrically connected to a frequency-voltage conversion module, and the frequency-voltage conversion module is electrically connected to the microcontroller through a differential signal amplification module.

[0012] Furthermore, the signal amplification module is also electrically connected to the coil excitation module, and the filtering module is also electrically connected to the microcontroller.

[0013] Furthermore, the excitation coil is flush with the top of the induction coil, and a first gap is formed between the top of the excitation coil and the steel string.

[0014] Furthermore, a second gap is formed between the excitation coil and the induction coil.

[0015] Furthermore, the shell is made of stainless steel.

[0016] Furthermore, a first blocking block and a second blocking block are arranged in the limiting slideway, and the first blocking block and the second blocking block are respectively located on two opposite sides of the sliding block. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A cross-sectional view of a vibrating-wire accelerometer in an embodiment of the utility model;

[0018] Figure 2 It is a structural block diagram of a vibrating-wire accelerometer in an embodiment of the utility model;

[0019] Description of main component symbols:

[0020] 10. Shell; 20. First limit block; 30. Second limit block; 40. Limit slideway; 50. Slider; 60. Clamping mechanism; 610. Clamping platform; 611. Clamping groove; 620. Bearing block; 630. Abutment block; 640. Clamping block; 650. Adjusting screw; 70. Steel string; 80. Monitoring component; 810. Bracket; 820. Excitation coil; 830. Induction coil; 910. Microcontroller; 920. Coil excitation module; 930. Signal amplification module; 940. Filter module; 950. Frequency-voltage conversion module; 960. Differential signal amplification module.

[0021] The following specific implementation manner will further illustrate the present utility model in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0022] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0023] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0025] See also Figure 1 and Figure 2 The vibrating-string accelerometer in the embodiment of the utility model includes a shell 10, the interior of the shell 10 is hollow to form a accommodating cavity. Preferably, the shell 10 includes an upper shell 10 and a lower shell 10, and the upper shell 10 and the lower shell 10 are detachably connected. In this embodiment, the shell 10 is made of stainless steel, which can effectively resist external corrosion in unattended online monitoring scenarios, and can shield external electromagnetic interference to avoid affecting the accuracy of monitoring.

[0026] The top and bottom of the accommodating cavity are respectively provided with a first limit block 20 and a second limit block 30, and a limit slide 40 is formed between the first limit block 20 and the second limit block 30. A slider 50 is slidably connected in the limit slide 40. The mass of the slider 50 can be set according to the range of the vibrating string accelerometer. The larger the mass of the slider 50, the smaller the range of the vibrating string accelerometer. It can be understood that the center line of the slider 50 is collinear with the sensitive axis of the vibrating string accelerometer. It should be noted that the sensitive axis of the vibrating string accelerometer is its measurement direction. In order to further limit the slider 50 to the sensitive axis of the vibrating string accelerometer, a first stop block and a second stop block are provided in the limit slide 40. The first stop block and the second stop block are respectively located on the opposite sides of the slider 50. By limiting the lateral movement of the slider 50, it is ensured that it always moves in the direction of the sensitive axis of the vibrating string accelerometer, which effectively improves the accuracy of monitoring.

[0027] Two clamping mechanisms 60 are provided at the bottom of the accommodating cavity. The two clamping mechanisms 60 are located on opposite sides of the slider 50. The opposite side walls of the slider 50 are connected to the steel string 70. Preferably, the slider 50 and the steel string 70 are detachably connected. It can be understood that the two steel strings 70 are located on the sensitive axis of the vibrating string accelerometer. The ends of the two steel strings 70 facing away from the slider 50 are detachably connected to the clamping mechanism 60. The clamping mechanism 60 is used to clamp the steel string 70 and adjust the tension of the steel string 70.

[0028] Specifically, the clamping mechanism 60 includes a clamping platform 610, on which a clamping groove 611 is provided which passes through the clamping platform 610, the clamping groove 611 corresponds to the position of the slider 50, a bearing block 620 is provided on the side of the clamping platform 610 which faces away from the slider 50, and an abutment block 630 is provided on the side of the bearing block 620 which faces the clamping platform 610, the abutment block 630 is located in the clamping groove 611, and the top of the clamping groove 611 is vertically movable and connected to the clamping block 640. In the present embodiment, the top of the clamping platform 610 is concave to form a screw hole which is connected to the clamping groove 611, and an adjusting screw 650 is screwed in the screw hole, and one end of the adjusting screw 650 is rotatably connected to the clamping block 640, and a clamping space is formed between the clamping block 640 and the abutment block 630, and the clamping space is used to place the steel string 70. 0 is provided with a string-drawing hole which passes through the bearing block 620, the string-drawing hole is connected with the clamping space, and the string-drawing hole corresponds to the position of the steel string 70. By rotating the adjusting screw, the adjusting screw can be moved vertically with the cooperation of the screw hole. Since one end of the adjusting screw is rotatably connected with the clamping block 640, the clamping block 640 can be moved vertically with the adjusting screw under the limitation of the side wall of the clamping groove 611, and the end of the steel string 70 facing away from the slider 50 is passed through the clamping space and the string-drawing hole in turn, and is placed on the side of the bearing block 620 facing away from the slider 50, and then the tension of the steel string 70 can be adjusted by pulling the steel string 70. When the preset tension is adjusted, the clamping block 640 is lowered by rotating the adjusting screw, and gradually approaches the abutment block 630, so as to complete the clamping of the steel string 70.

[0029] A monitoring component 80 is arranged between the two clamping mechanisms 60 and the slider 50. The monitoring component 80 includes a bracket 810 connected to the bottom of the accommodating cavity. An excitation coil 820 and an induction coil 830 are arranged on the top of the bracket 810. The excitation coil 820 and the induction coil 830 both correspond to the positions of the steel string 70. The excitation coil 820 is used to apply electromagnetic suction to the steel string 70 to make the steel string 70 vibrate, and the induction coil 830 is used to collect the vibration signal of the steel string 70. It should be noted that the excitation coil 820 is flush with the top of the induction coil 830, and a first interval is formed between the top of the excitation coil 820 and the steel string 70, and a second interval is formed between the excitation coil 820 and the induction coil 830. By setting the first interval, it is possible to avoid the steel string 70 from touching the excitation coil 820 and / or the induction coil 830 when vibrating. By setting the second interval, it is possible to avoid mutual interference between the excitation coil 820 and the induction coil 830, thereby further improving the accuracy of monitoring.

[0030] Because the steel string 70 is located on the sensitive axis of the vibrating string accelerometer, when the vibrating string accelerometer is accelerated, one of the steel strings 70 is compressed and the other steel string 70 is pulled, forming a differential structure, which can improve the sensitivity of the vibrating string accelerometer and the linear measurement range of the vibrating string accelerometer; by setting the clamping mechanism 60 and the detachable connection between the clamping mechanism 60 and the steel string 70, the tension of the steel string 70 can be easily adjusted to ensure the accuracy of monitoring, and the steel string 70 can be regularly inspected. The steel string 70 can be replaced separately to ensure the long-term stability of the vibrating string accelerometer; the electromagnetic attraction is applied to the steel string 70 through the excitation coil 820, the steel string 70 vibrates, and the vibration signal is collected through the induction coil 830. The acceleration of the vibrating string accelerometer can be acquired based on the vibration frequency difference between the vibration signals of the two steel strings 70. The overall structure of the vibrating string accelerometer is simple. In the unattended online low-frequency vibration monitoring scenario, the manufacturing cost can be effectively reduced, and it is suitable for large-scale promotion.

[0031] It can be understood that the vibrating-string accelerometer further includes a microcontroller 910, and the microcontroller 910 is electrically connected to the excitation coil 820 through a coil excitation module 920, and the coil excitation module 920 is used to provide power to the excitation coil 820. In this embodiment, the coil excitation module 920 includes a constant voltage power supply. The induction coil 830 is electrically connected to a signal amplification module 930. In this embodiment, the signal amplification module 930 includes a single-ended signal conditioning circuit, and the signal amplification module 930 is electrically connected to a filter module 940. In this embodiment, the filter module 940 includes an active low-pass filter and an active pass filter. The filter module 940 is electrically connected to a frequency-voltage conversion module 950, and the frequency-voltage conversion module 950 is electrically connected to the microcontroller 910 through a differential signal amplification module 960. When starting the vibrating string accelerometer, the microcontroller 910 sends a single pulse, multiple pulses or PWM combination waveform as an excitation signal through the IO serial port to excite the steel string 70 for the first time. After the steel string 70 vibrates, the induction coil 830 picks up the vibration signal of the steel string 70, which is amplified by the signal amplification module 930 and then transmitted to the filter module 940. The filter module 940 filters the signal outside the bandwidth range of the induction coil 830. The frequency-voltage conversion circuit converts the filtered vibration signal into a DC voltage signal and transmits it to the differential signal amplification module 960. Assuming that the vibration signal of one of the steel strings 70 is 2400 Hz (under pressure), the other steel string The vibration signal of 70 is 2580Hz (under tension). According to the classical string formula, the relationship between tension and frequency is a square relationship. Therefore, when the slider 50 is subjected to acceleration, the tension of one of the steel strings 70 decreases, and the tension of the other steel string 70 increases. According to the balance of forces, the reduced tension is equal to the increased tension. However, due to the square relationship, the frequency increase is less than the frequency decrease. Then, the output voltages of the two frequency-to-voltage conversion modules 950 are 2.40V and 2.58V respectively. The differential signal amplification module 960 includes an instrument amplifier, and transmits the obtained differential voltage between the two output voltages to the microcontroller 910. The microcontroller 910 obtains the acceleration based on the differential voltage.

[0032] Furthermore, the signal amplification module 930 is also electrically connected to the coil excitation module 920, and the filtering module 940 is also electrically connected to the microcontroller 910. The signal amplification module 930 obtains the vibration signal collected by the induction coil 830, and after amplification, in addition to transmitting it to the subsequent link, it is also fed back to the coil excitation module 920 to ensure that the coil excitation module 920 can continuously excite the steel string 70 through the excitation coil 820 in the same phase, so that the steel string 70 generates a continuous vibration signal, ensuring that the output of the vibrating string accelerometer remains continuous. By electrically connecting the filtering module 940 to the microcontroller 910, the microcontroller 910 can sample the output signal of the filtering module 940 through the internal analog-to-digital converter and calculate the amplitude to determine the vibration intensity of the current signal, thereby controlling the gate time of the signal amplification module 930 entering the coil excitation module 920. By controlling the gate time and frequency, the continuous vibration amplitude of the steel string 70 is stabilized, and the monitoring accuracy is further improved.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0034] The above-mentioned embodiments only express several implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A vibrating-wire accelerometer, characterized in that: The invention comprises a shell, wherein the shell is hollow inside to form a accommodating cavity, a first limit block and a second limit block are respectively arranged at the top and the bottom of the accommodating cavity, a limit slideway is formed between the first limit block and the second limit block, a slider is slidably connected in the limit slideway, two clamping mechanisms are arranged at the bottom of the accommodating cavity, the two clamping mechanisms are located on opposite sides of the slider, the opposite side walls of the slider are connected to steel strings, the two steel strings are located on the sensitive axis of the vibrating string accelerometer, the ends of the two steel strings facing away from the slider are disassembled and connected to the clamping mechanisms, the clamping mechanisms are used to clamp the steel strings and adjust the tension of the steel strings, a monitoring component is arranged between the two clamping mechanisms and the slider, the monitoring component comprises a bracket connected to the bottom of the accommodating cavity, an excitation coil and an induction coil are arranged at the top of the bracket, the excitation coil and the induction coil both correspond to the positions of the steel strings, the excitation coil is used to apply electromagnetic suction to the steel string to make the steel string vibrate, and the induction coil is used to collect the vibration signal of the steel string.

2. The vibrating-wire accelerometer according to claim 1, wherein: The clamping mechanism includes a clamping table, a clamping groove passing through the clamping table is provided on the clamping table, the clamping groove corresponds to the position of the slider, a bearing block is provided on the side of the clamping table facing away from the slider, an abutment block is provided on the side of the bearing block facing the clamping table, the abutment block is located in the clamping groove, the top of the clamping groove is vertically movable and connected to the clamping block, a clamping space is formed between the clamping block and the abutment block, a string-drawing hole passing through the bearing block is provided on the bearing block, the string-drawing hole is connected to the clamping space, and the string-drawing hole corresponds to the position of the steel string.

3. The vibrating-wire accelerometer according to claim 2, wherein: The top of the clamping platform is concave to form a screw hole connected with the clamping groove, and an adjusting screw is screwed in the screw hole, and one end of the adjusting screw is rotatably connected to the clamping block.

4. The vibrating-wire accelerometer according to claim 1, wherein: The vibrating string accelerometer also includes a microcontroller, which is electrically connected to the excitation coil through a coil excitation module, the induction coil is electrically connected to a signal amplification module, the signal amplification module is electrically connected to a filtering module, the filtering module is electrically connected to a frequency-voltage conversion module, and the frequency-voltage conversion module is electrically connected to the microcontroller through a differential signal amplification module.

5. The vibrating-wire accelerometer according to claim 4, characterized in that: The signal amplification module is also electrically connected to the coil excitation module, and the filtering module is also electrically connected to the microcontroller.

6. The vibrating-wire accelerometer according to claim 1, wherein: The excitation coil is flush with the top of the induction coil, and a first gap is formed between the top of the excitation coil and the steel string.

7. The vibrating-wire accelerometer according to claim 1, wherein: A second gap is formed between the excitation coil and the induction coil.

8. The vibrating-wire accelerometer according to claim 1, wherein: The shell is made of stainless steel.

9. The vibrating-wire accelerometer according to claim 1, wherein: A first blocking block and a second blocking block are arranged in the limiting slideway, and the first blocking block and the second blocking block are respectively located on two opposite sides of the sliding block.

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