CN205506202U - Infrasonic wave detector - Google Patents

Abstract

The utility model relates to an infrasonic wave detector, which comprises a signal amplifying circuit, a low-pass filter circuit, a signal attenuation circuit, a program control gain amplifying circuit, a direct current bias circuit and a controller; the infrasonic wave sensor comprises a shell, a receiving flat diaphragm, a collecting flat diaphragm, a receiving flat diaphragm hoop, a collecting flat diaphragm hoop, a base and a PVDF piezoelectric film. The utility model discloses an infrasonic wave sensor real-time detection infrasonic wave signal through the demonstration of display screen realization information, reports to the police through alarm device when detecting unusually, the utility model discloses convenient operation has very strong practicality, the utility model provides an infrasonic wave sensor adopts the infrasonic wave to receive flat diaphragm and the flat diaphragm of infrasonic wave collection, has realized that the infrasonic wave receives the effective isolation of flat diaphragm and signal collection flat diaphragm, is favorable to receiving signal's even stable transmission.

Description

an infrasound detector

technical field

The utility model relates to the field of equipment detectors, in particular to an infrasonic wave detector.

Background technique

In engineering applications, when the infrared rangefinder measures the distance between a certain point and the measuring instrument, if there is an obstacle in the middle, the infrared will return when it encounters the obstacle, and the measured distance will become the distance between the measuring instrument and the measuring instrument. The distance of obstacles makes it impossible to measure; during ultrasonic ranging, ultrasonic waves will reflect when they encounter objects, so when there are obstacles in front of the measured object, the detection data cannot be obtained correctly.

Rotating equipment or pipelines will emit various noises due to friction during operation. The noise includes not only ultra-low frequency infrasonic waves, but also audible frequency band sound waves and ultra-high frequency ultrasonic waves. Since the transmission distance of sound wave signals increases with the frequency Increase and decrease rapidly, for example: the transmission distance of the sound wave signal with a frequency of 1000Hz is 90% energy attenuation after reaching 7Km, while the energy of the 1Hz infrasound wave is attenuated by 90% only after the transmission distance exceeds 3000Km. Therefore, the remote non-contact fault diagnosis of the abnormal state of the equipment can be realized through the infrasonic frequency band.

At present, domestic and international on-line acoustic diagnosis of abnormal equipment operation is mainly concentrated in the field of ultrasonic flaw detection and acoustic emission diagnosis.

Currently, there are few records of infrasonic sensors based on PVDF films. In recent decades, some achievements have been made in the detection of infrasonic waves, and some infrasonic wave sensors with excellent performance have been developed, which are basically capacitive infrasonic wave sensors. However, capacitive sensors also have some problems. For example, the test results will be affected under the conditions of high temperature, high humidity and high excitation. Therefore, a new structure and new sensitive elements are proposed here to improve the measurement sensitivity of the infrasonic sensor, reduce clutter interference, and effectively prevent the influence of high temperature, high humidity, and high excitation environments.

Utility model content

The utility model provides an infrasonic wave detector for solving the technical problems that the measurement sensitivity of the current infrasonic wave sensor is not high, the stability is not strong, and the detection data cannot be obtained correctly.

The technical scheme that the utility model takes for solving the technical problem existing in the known technology is:

An infrasonic wave detector, comprising a signal amplifying circuit, a low-pass filter circuit, a signal attenuating circuit, a program-controlled gain amplifying circuit, a DC bias circuit, and a controller; the signal amplifying circuit amplifies the signal and inputs the signal To a low-pass filter circuit, the low-pass filter circuit performs low-pass filtering on the signal and inputs the filtered signal to the signal attenuation circuit, and the signal attenuation circuit attenuates the signal and inputs the attenuated signal to the programmable gain amplifier circuit, the program-controlled gain amplifier circuit performs gain amplification on the signal and inputs the amplified signal to the controller and the DC bias circuit respectively;

The infrasonic wave detector is also provided with an infrasonic wave sensor; the infrasonic wave sensor inputs the real-time detected infrasonic wave signal to the signal amplification circuit;

The infrasonic sensor comprises a shell, a receiving flat diaphragm, a collecting flat diaphragm, a receiving flat diaphragm hoop, a collecting flat diaphragm hoop, a base, a PVDF piezoelectric film, and the housing is fixed on the base, receiving the flat diaphragm and collecting The flat diaphragm is fixed on the two cross-sectional ends of the housing by receiving the flat diaphragm hoop and collecting the flat diaphragm hoop, and the PVDF piezoelectric film array is arranged on the side of the collecting flat diaphragm close to the base; the infrasonic wave detector also includes A/D conversion circuit, display screen and alarm device; the DC bias circuit biases the signal and inputs the signal to the A/D conversion circuit, and the A/D conversion circuit performs A/D conversion on the signal and The signal is input to the controller, and the controller sorts the signal and feeds the signal back to the display screen; the display screen is electrically connected to the alarm device, and the display screen is an intelligent touch display screen.

Further, the shell is cylindrical, and its two cross-sectional end edges are threaded; the receiving flat diaphragm ferrule, the collecting flat diaphragm ferrule and the base are concentric circles, and the receiving flat diaphragm ferrule and the collecting flat diaphragm ferrule There are threads along the inner edge of the receiving flat diaphragm hoop and the collection flat diaphragm hoop to match the threads on the edges of the two sections of the housing.

Further, the cavity between the receiving flat diaphragm and the collecting flat diaphragm is filled with insulating lubricating oil; the base is provided with fixing holes and signal wire lead-out holes.

Further, the programmable gain amplification circuit includes a programmable gain amplifier and a first operational amplifier, the IN+ terminal pin of the programmable gain amplifier is connected to the output terminal of the signal attenuation circuit through a first resistor, and the OUT terminal pin of the programmable gain amplifier is connected to the output terminal of the signal attenuation circuit. The DC bias circuit is connected to the controller, the REF terminal pin of the programmable gain amplifier is connected to the output terminal of the first operational amplifier, and the non-inverting terminal of the first operational amplifier is grounded through the sixth resistor and passed through the seventh resistor connected in series in sequence and the eighth resistor are connected to the power supply, and the inverting terminal of the first operational amplifier is connected to its own output terminal.

The advantages and positive effects of the utility model are: the utility model detects the infrasonic signal in real time through the infrasonic sensor; at the same time, through the signal amplification circuit, the low-pass filter circuit, the signal attenuation circuit, the program-controlled gain amplification circuit, the DC bias circuit and the A/ The D conversion circuit realizes the conditioning of the signal; moreover, the display of the information is realized through the display screen, and the alarm device is used to alarm when the abnormality is detected. The present invention is easy to operate and has strong practicability.

The infrasonic wave sensor provided by the utility model adopts the infrasonic wave receiving flat diaphragm and the infrasonic wave collecting flat diaphragm, realizes the effective isolation of the infrasonic wave receiving flat diaphragm and the signal collecting flat diaphragm, and is conducive to the uniform and stable transmission of the received signal. In addition, the filling of insulating lubricating oil can increase the damping coefficient of the sensor to enhance the ability of the sensor to prevent clutter interference. The low-frequency range of the piezoelectric film infrasonic sensor can enhance the detection signal and reduce the error of the detection signal; the infrasonic sensor provided by the utility model adopts PVDF new piezoelectric film, and utilizes its characteristics that are not easily affected by factors such as high temperature and high humidity to improve The measurement sensitivity of the infrasonic wave sensor is improved, the response effect to low frequency and ultra-low frequency is good, the clutter interference is reduced, and the normal use of the infrasonic wave sensor under high temperature and high humidity conditions is realized.

Description of drawings

Fig. 1 is a schematic structural diagram of an infrasonic wave detector provided by an embodiment of the present invention;

Fig. 2 is a top view structural schematic diagram of the infrasonic wave sensor provided by the utility model;

Fig. 3 is the structural representation of the infrasonic wave acquisition flat diaphragm and PVDF piezoelectric film array of the infrasonic wave sensor provided by the utility model;

Fig. 4 is a controller connection diagram provided by the utility model;

In the figure: 1, infrasonic sensor; 1-1, shell; 1-2, receiving flat diaphragm; 1-3, collecting flat diaphragm; 1-4, receiving flat diaphragm hoop; 1-5, collecting flat diaphragm hoop; 1-6, base; 1-7, PVDF piezoelectric film; 1-8, fixing hole; 1-9, signal wire lead-out hole; 1-10, insulating lubricating oil; 2, signal amplification circuit; 3, Low-pass filter circuit; 4. Signal attenuation circuit; 5. Program-controlled gain amplifier circuit; 6. DC bias circuit; 7. A/D conversion circuit; 8. Display screen; 9. Controller; 10. Alarm device.

Fig. 5 is a schematic diagram of the circuit structure of the programmable gain amplifier circuit provided by the embodiment of the utility model

detailed description

In order to further understand the invention content, characteristics and effects of the present utility model, the following examples are given, and detailed descriptions are given below in conjunction with the accompanying drawings.

As shown in Figures 1 to 4, the infrasonic wave detector provided in this embodiment includes a signal amplification circuit 2, a low-pass filter circuit 3, a signal attenuation circuit 4, a programmable gain amplification circuit 5, and a DC bias circuit 6 , controller 9; the signal amplification circuit 2 amplifies the signal and inputs the signal to the low-pass filter circuit 3, and the low-pass filter circuit 3 performs low-pass filtering on the signal and inputs the filtered signal to the signal attenuation circuit 4, and the signal attenuation The circuit 4 attenuates the signal and inputs the attenuated signal to the programmable gain amplifier circuit 5, and the programmable gain amplifier circuit 5 amplifies the signal and inputs the amplified signal to the controller 9 and the DC bias circuit 6 respectively;

The infrasonic wave detector is also provided with an infrasonic wave sensor 1; the infrasonic wave sensor 1 inputs the real-time detected infrasonic wave signal to the signal amplification circuit 2;

The infrasonic wave sensor 1 detects the infrasonic wave signal in real time and inputs the detected signal to the signal amplification circuit 2. The infrasonic wave sensor includes a cylindrical shell 1-1, a receiving flat diaphragm 1-2, a collecting flat diaphragm 1-3, and a receiving flat diaphragm Hoop 1-4, collection flat diaphragm hoop 1-5, base 1-6, PVDF piezoelectric film 1-7, shell 1-1 fixed on the base 1-6, receiving flat diaphragm 1-2 and collection The flat diaphragm 1-3 is fixed on the two cross-sectional ends of the housing 1-1 by receiving the flat diaphragm hoop 1-4 and collecting the flat diaphragm hoop 1-5, and is used to generate deformation under the action of infrasonic waves. Eight pieces of PVDF piezoelectric The thin film 1-7 array is arranged on the side of the collection flat diaphragm 1-3 close to the base 1-6, and is used to enhance the piezoelectric signal and reduce the signal output error; wherein the shell 1-1 is cylindrical, and its two cross-sectional ends The outer surface is provided with threads; the receiving flat diaphragm hoop 1-4, the collection flat diaphragm hoop 1-5 and the base 1-6 are concentric circles, and the inner diameter of the concentric circles is consistent with the inner diameter of the cylindrical shell 1-1; the receiving The inner edge of the flat diaphragm ferrule 1-4 and the collection flat diaphragm ferrule 1-5 are threaded, the inner edge of the receiving flat diaphragm ferrule 1-4 and the collection flat diaphragm ferrule 1-5 are threaded and the two cross-sectional ends of the shell 1-1 The edge threads are matched, and the infrasonic wave receiving flat diaphragm hoop 1-4 and the collecting flat diaphragm hoop 1-5 are respectively screwed into the two cross-sectional ends of the cylindrical shell 1-1 to achieve the purpose of fixing and sealing the internal structure of the entire sensor ; The cavity between the receiving flat diaphragm 1-2 and the collection flat diaphragm 1-3 is filled with insulating lubricating oil 1-10, which is conducive to realizing the isolation of the receiving flat diaphragm 1-2 and the collection flat diaphragm 1-3 Effective isolation to make signal transmission more stable and increase the damping of the system; and to keep absolutely sealed without air; there are four fixing holes 1-8 on the base 1-6 for fixing the infrasonic sensor, and the base is set There are signal lead wire outlet holes 1-9, which are used to lead out the output signal lines of the PVDF piezoelectric film 7 array pasted on the infrasonic wave collection flat diaphragm 1-3.

The infrasonic wave detector also includes an A/D conversion circuit 7, a display screen 8 and an alarm device 10; the DC bias circuit 6 biases the signal and inputs the signal to the A/D conversion circuit 7, and the A/D The D conversion circuit 7 performs A/D conversion on the signal and inputs the signal to the controller 9, and the controller 9 organizes the signal and feeds the signal back to the display screen 8; the display screen is electrically connected to the alarm device 10, and the display Screen 10 is an intelligent touch display.

In this embodiment, the infrasonic wave signal is detected in real time by the infrasonic wave sensor 1; at the same time, it is realized by the signal amplification circuit 2, the low-pass filter circuit 3, the signal attenuation circuit 4, the program-controlled gain amplification circuit 5, the DC bias circuit 6 and the A/D conversion circuit 7. Signal conditioning; and, the detected infrasound signal is displayed on the display screen 8, so that the user can easily know the strength of the surrounding infrasound signal.

The program-controlled gain amplifier circuit 5 of this embodiment can adopt the circuit structure shown in Figure 5, including the program-controlled gain amplifier U1 and the first operational amplifier A1, the IN+ terminal pin of the program-controlled gain amplifier U1 and the signal attenuation circuit 4 through the first resistor R1 The output terminal of the program-controlled gain amplifier U1 is connected with the DC bias circuit 6 and the controller 9, the REF terminal of the program-controlled gain amplifier U1 is connected with the output terminal of the first operational amplifier A1, and the output terminal of the first operational amplifier A1 The non-inverting terminal is grounded through the sixth resistor R6 and connected to the power supply through the seventh resistor R7 and the eighth resistor R8 connected in series in sequence, and the inverting terminal of the first operational amplifier A1 is connected to its own output terminal. In order to optimize the system, the display screen 8 of this embodiment is an intelligent touch display screen, the user can directly touch to adjust the work, and when the detection is abnormal, the alarm device 10 will give an alarm.

The working principle of the infrasonic wave sensor provided by the utility model is as follows: under the action of external infrasonic waves, deformation occurs on the infrasonic wave receiving flat diaphragm 1-2, and the silicone oil 1-10 transmits the deformation stably to the infrasonic wave collecting flat diaphragm 1-3, and the infrasonic wave collecting The PVDF piezoelectric film array on the flat diaphragm 1-3 converts the deformation caused by the infrasonic wave into a charge signal, and the output charge is proportional to the strain received, and the obtained charge is drawn from the signal line to hole 1 -9 leads out, and the information of the external infrasound wave can be obtained after processing such as external charge amplification.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model in any form. Any simple modifications made to the above embodiments according to the technical essence of the present utility model are equivalent to changes and modifications. All belong to the scope of the technical solution of the utility model.

Claims (1)

1. an infrasonic wave detector, this infrasonic wave detector includes signal amplification circuit, low-pass filter circuit, signal attenuation circuit, programme-controlled gain amplifying circuit, DC bias circuit, controller；Signal is amplified and inputs a signal into low-pass filter circuit by described signal amplification circuit, signal is carried out low-pass filtering and inputs filtered signal to signal attenuation circuit by described low-pass filter circuit, signal is carried out decaying and inputting the signal after decay to programme-controlled gain amplifying circuit by described signal attenuation circuit, and the signal after signal is carried out gain amplification and will amplify by described programme-controlled gain amplifying circuit is separately input into controller and DC bias circuit；It is characterized in that, this infrasonic wave detector is additionally provided with infrasonic sensor；The infrasonic wave signal detected in real time is inputted to signal amplification circuit by described infrasonic sensor；

Described infrasonic sensor includes shell, receives flat diaphragm, collection flat diaphragm, reception flat diaphragm hoop, collection flat diaphragm hoop, pedestal, PVDF piezoelectric membrane, shell is fixed on pedestal, receiving flat diaphragm and collection flat diaphragm to be fixed on the two sections end of shell with gathering flat diaphragm hoop by receiving flat diaphragm hoop, PVDF piezoelectric membrane array is arranged on the side of the close pedestal gathering flat diaphragm；Described infrasonic wave detector also includes A/D change-over circuit, display screen and alarm device；Signal is biased and inputs a signal into A/D change-over circuit by described DC bias circuit, and signal is carried out A/D conversion and inputs a signal into controller by described A/D change-over circuit, and signal is carried out arranging and signal being fed back to display screen by described controller；Display screen and alarm device electrical connection, described display screen is intelligent touch display screen；

Described shell is cylindrical, and its two sections end margin is threaded；Receiving flat diaphragm hoop, collection flat diaphragm hoop and pedestal is concentric circles, and in receiving flat diaphragm hoop and gathering flat diaphragm hoop, edge is threaded, and threadingly matches with shell two sections end margin screw thread in receiving flat diaphragm hoop and gathering flat diaphragm hoop；

Insulation lubricating oil is filled in the described cavity received between flat diaphragm and collection flat diaphragm；Fixing hole and holding wire fairlead it is provided with on pedestal；

Described programme-controlled gain amplifying circuit includes gain-programmed amplifier and the first amplifier, the IN+ end foot of described gain-programmed amplifier is connected with the outfan of signal attenuation circuit by the first resistance, the OUT terminal foot of described gain-programmed amplifier is connected with DC bias circuit and controller, the REF end foot of described gain-programmed amplifier and the outfan of the first amplifier connect, the in-phase end of described first amplifier accesses power supply by the 6th resistance eutral grounding and by the 7th resistance being sequentially connected in series and the 8th resistance, and the end of oppisite phase of described first amplifier is connected with the outfan of self.