Ultrasonic sound velocity measuring device

Abstract

The utility model belongs to the technical field of sound velocity measurement, and discloses an ultrasonic sound velocity measuring device which comprises a signal generator. The signal generator is used for sending a to-be-detected sound signal. The capacitive grating distance measuring system comprises a first supporting plate. The first supporting plate and the second supporting plate are vertically parallel and arranged at intervals, and the ruler is horizontally arranged between the first supporting plate and the second supporting plate. The transmitting end piezoelectric transducer is arranged on the scale in a sliding manner and is opposite to the receiving end piezoelectric transducer; the capacitive grating sensor is positioned above the scale and can move synchronously with the receiving end piezoelectric transducer; the output end of the receiving end piezoelectric transducer and the output end of the capacitive grating sensor are connected with the input end of the data collector. The schlieren imaging system is arranged between the first supporting plate and the second supporting plate; the schlieren imaging system can move synchronously with the receiving end piezoelectric transducer; according to the utility model, the accuracy of sound wavelength measurement results can be effectively ensured, and the accuracy of sound velocity measurement results is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of sound velocity measurement, and particularly relates to an ultrasonic sound velocity measurement device. Background Art

[0002] An ultrasonic sound velocity measuring instrument is an instrument used to measure the propagation speed of sound waves in a medium. Currently, for existing ultrasonic sound velocity measuring instruments, when measuring the sound velocity, an oscilloscope is needed to display the change of the received signal. When the receiving piezoelectric transducer moves from a node of a standing wave to an antinode, the sine waveform on the oscilloscope also shows a change from strong to weak. By measuring the distance between the strongest position (node position) of the waveform displayed on the oscilloscope measured by a scale and the next strongest position (node position) with a ruler, the moving distance is 1 / 2 of the wavelength, and then the propagation speed of sound is calculated.

[0003] However, when the existing ultrasonic sound velocity measuring instrument measures the sound velocity, due to the inability to obtain the precise position of the displayed waveform, there are technical problems of low measurement accuracy and poor visualization, which are specifically as follows: (1) There is a large human error when judging the node position. Specifically, when using a rotating handwheel to find the strongest position of the waveform displayed on the oscilloscope, that is, the node position, it is possible that the next moment has passed the strongest position, but due to the introduction of an empty travel difference when the handwheel rotates in the reverse direction, it cannot return backward to the strongest position of the signal displayed on the oscilloscope; or before reaching the strongest position of the displayed waveform, this position is recorded as the node position, thereby introducing a large measurement error and reducing the measurement accuracy; (2) Although the oscilloscope shows the change in the strength of the signal received by the receiving piezoelectric transducer, the actual situation of the standing wave formed between the two piezoelectric transducers cannot be perceived. Summary of the Utility Model

[0004] Aiming at the technical problems existing in the prior art, the utility model provides an ultrasonic sound velocity measurement device to solve the technical problems of low measurement accuracy and poor visualization when the existing ultrasonic sound velocity measuring instrument measures the sound velocity due to the inability to obtain the precise position of the displayed waveform.

[0005] To achieve the above object, the technical solution adopted by the utility model is as follows:

[0006] The utility model provides an ultrasonic sound velocity measurement device, which includes a signal generator, a capacitive grating ranging system and a schlieren imaging system; the signal generator is used to generate a sound signal to be measured in the capacitive grating ranging system, and the capacitive grating ranging system includes a first support plate, a second support plate, a scale, a transmitting end piezoelectric transducer, a receiving end piezoelectric transducer, a capacitive grating sensor and a data collector;

[0007] The first support plate and the second support plate are vertically parallel and spaced apart, and the scale is horizontally arranged between the first support plate and the second support plate; the transmitting piezoelectric transducer is arranged at the end of the scale and is placed inside the first support plate; the receiving piezoelectric transducer is slidably arranged on the scale and is oppositely arranged with the transmitting piezoelectric transducer; wherein, the to-be-detected sound signal can generate a sound standing wave between the transmitting piezoelectric transducer and the receiving piezoelectric transducer; the capacitive grating sensor is located above the scale and can move synchronously with the receiving piezoelectric transducer; the output ends of the receiving piezoelectric transducer and the capacitive grating sensor are both connected to the input end of the data collector;

[0008] The schlieren imaging system is arranged between the first support plate and the second support plate and is located between the transmitting piezoelectric transducer and the receiving piezoelectric transducer; wherein, the schlieren imaging system can move synchronously with the receiving piezoelectric transducer, and the schlieren imaging system is used to observe the schlieren image of the sound propagation of the to-be-detected sound signal in the air.

[0009] Further, the scale includes a scale body, a guide rod, a lead screw and a sliding rod; the scale body, the guide rod and the lead screw are all horizontally arranged between the first support plate and the second support plate; wherein, the guide rod is located on the upper side of the scale body, the lead screw is arranged on the lower side of the scale body, and the guide rod and the lead screw are in the same vertical plane;

[0010] The upper end of the sliding rod is slidably connected to the guide rod, the middle part of the sliding rod is sleeved on the lead screw, and the lower end of the sliding rod extends below the lead screw; wherein, the sliding rod is threadedly connected with the lead screw; the receiving piezoelectric transducer is installed at the lower end of the sliding rod, and the capacitive grating sensor is arranged on the upper side of the upper end of the sliding rod and is located on the upper surface of the scale body.

[0011] Further, the capacitive grating ranging system further includes an output voltage control circuit, a first display screen and a second display screen;

[0012] The input end of the output voltage control circuit is connected to the output end of the receiving piezoelectric transducer, and the output end of the output voltage control circuit is connected to the input end of the data collector; the first output end of the data collector is connected to the input end of the first display screen, and the second output end of the data collector is connected to the input end of the second display screen.

[0013] Further, the capacitive grating ranging system further includes a rotating handwheel; the rotating handwheel is arranged on the outer side of the upper end of the second support plate and is connected to the end of the lead screw; wherein, the rotating handwheel is used to drive the lead screw to horizontally rotate around the axis of the lead screw.

[0014] Further, the schlieren imaging system includes a schlieren imaging track, a photographic module, a light source module, a connecting gripper and a concave mirror; the schlieren imaging track is horizontally slidably arranged between the first support plate and the second support plate, and the axis of the schlieren imaging track is perpendicular to the connection line between the transmitting piezoelectric transducer and the receiving piezoelectric transducer;

[0015] The photographic module, the light source module and the concave mirror are all arranged on the schlieren imaging track for observing the sound schlieren image; the connecting gripper is arranged between the schlieren imaging track and the sliding rod; wherein, the upper end of the connecting gripper is connected to the lower end of the sliding rod, and the lower end of the connecting gripper is fixedly connected to the upper surface of the schlieren imaging track.

[0016] Further, the photographic module includes a camera and a camera base; the camera base is arranged at the first end of the schlieren imaging track, and the camera is installed on the camera base; wherein, the camera base is a height-adjustable base.

[0017] Further, the light source module includes a light-emitting light source, a blade and a light source lifting platform; the light source lifting platform is arranged on the schlieren imaging track and is arranged close to the side of the photographic module; the light source is arranged on one side of the top end of the light source lifting platform, and the blade is arranged on the other side of the top end of the light source lifting platform.

[0018] Further, the schlieren imaging system further includes a concave mirror base; the concave mirror base is arranged at the second end of the schlieren imaging track, and the concave mirror is installed on the concave mirror base.

[0019] Further, the schlieren imaging system further includes a first roller and a second roller; the first roller is arranged at the bottom end of the camera base, and the second roller is arranged at the bottom end of the concave mirror base.

[0020] Further, the schlieren imaging system further includes a track telescopic rod; the track telescopic rod is telescopically arranged between the concave mirror base and the second end of the schlieren imaging track; wherein, the axis of the track telescopic rod is parallel to the long axis of the schlieren imaging track.

[0021] Compared with the prior art, the beneficial effects of the present utility model are:

[0022] The ultrasonic sound velocity measuring device provided by the utility model slidably arranges both the receiving piezoelectric transducer and the capacitive grating sensor on the scale. The receiving piezoelectric transducer is used to convert the sound signal propagated by the sound signal to be measured in the medium into a voltage signal, and the capacitive grating sensor is used to monitor the position of the receiving piezoelectric transducer. Then, a data collector is used to collect the voltage signal output by the receiving piezoelectric transducer and the position data output by the capacitive grating sensor. When measuring the sound velocity, the collected voltage data and position data are used as the basic data for determining the position of the peak voltage, so as to accurately obtain the position of the peak voltage, without the need for artificial position judgment and measurement through the display waveform output by the oscilloscope. Furthermore, the accuracy of the measurement result of the sound wavelength can be effectively ensured, and the accuracy of the sound velocity measurement result is improved. Secondly, through the schlieren imaging system, the schlieren image of the sound propagation of the sound signal to be measured in the air can be visually observed, realizing the visual measurement of the sound velocity. The device of the utility model has a simple structure, does not require cumbersome calibration, and has a simple operation process, which can effectively improve the accuracy and visualization degree of the sound velocity measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a schematic diagram of the overall structure of the ultrasonic sound velocity measuring device provided by the utility model;

[0025] Figure 2 It is a schematic diagram of the structure of the capacitive grating ranging system in the utility model;

[0026] Figure 3 It is a schematic diagram of the circuit connection in the capacitive grating ranging system of the utility model;

[0027] Figure 4 It is a schematic diagram of the structure of the schlieren imaging system in the utility model;

[0028] Figure 5 It is a position-voltage curve graph in the utility model.

[0029] Among them, 1 is a capacitive grating ranging system, and 2 is a schlieren imaging system; 11 is a first support plate, 12 is a second support plate, 13 is a scale body, 14 is a guide rod, 15 is a lead screw, 16 is a sliding rod, 17 is a transmitting piezoelectric transducer, 18 is a receiving piezoelectric transducer, 19 is a capacitive grating sensor, 110 is an output voltage control circuit, 111 is a data collector, 112 is a first display screen, 113 is a second display screen, and 114 is a rotary handwheel; 21 is a schlieren imaging track, 22 is a camera, 23 is a camera base, 24 is a light-emitting light source, 25 is a blade, 26 is a light source lifting platform, 27 is a connecting gripper, 28 is a concave mirror, 29 is a concave mirror base, 210 is a first roller, 211 is a second roller, and 212 is a track telescopic rod. Detailed implementation manners

[0030] In order to make the technical problems, technical solutions, and beneficial effects solved by this application clearer and more understandable, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application; obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0031] As shown in the attac Figure 1 hment, the present utility model provides an ultrasonic sound velocity measurement device, including a signal generator, a capacitive grating ranging system 1, and a schlieren imaging system 2; the output end of the signal generator is connected to the signal input end of the capacitive grating ranging system, and the signal generator is used to generate a transmitted sound signal to be measured in the capacitive grating ranging system 1; the capacitive grating ranging system is used to obtain voltage data corresponding to the sound signal to be measured during the propagation process in the medium and position data corresponding to different voltage data; the schlieren imaging system 2 is used to observe the schlieren image of the sound propagation of the sound signal to be measured in the air.

[0032] As shown in the attac Figures 2 - 3 hment, the capacitive grating ranging system 1 includes a first support plate 11, a second support plate 12, a scale, a transmitting piezoelectric transducer 17, a receiving piezoelectric transducer 18, a capacitive grating sensor 19, an output voltage control circuit 110, a data collector 111, a first display screen 112, a second display screen 113, and a rotary handwheel 114.

[0033] The first support plate 11 and the second support plate 12 are vertically parallel and spaced apart, and the scale is horizontally arranged between the first support plate 11 and the second support plate 12; wherein, one end of the scale is connected to the first support plate 11, and the other end of the scale is connected to the second support plate 12; the transmitting piezoelectric transducer 17 is arranged inside the first support plate 11 and is located below the end of the scale; the transmitting piezoelectric transducer 18 is slidably arranged on the scale and is oppositely arranged with the transmitting piezoelectric transducer 17.

[0034] The output end of the signal generator is connected to the input end of the transmitting piezoelectric transducer 17, and is used to generate a sound signal to be measured with the same frequency through the transmitting piezoelectric transducer 17; wherein, the sound signal to be measured can generate a sound standing wave between the transmitting piezoelectric transducer 17 and the receiving piezoelectric transducer 18; the capacitive grating sensor 19 is located above the scale and can move synchronously with the receiving piezoelectric transducer 18.

[0035] It should be noted that the piezoelectric transducer is a device for converting between sound signals and electrical signals; wherein, the transmitting piezoelectric transducer 17 is used to convert the ultrasonic frequency electrical signal output by the signal generator into a sound signal of the same frequency to form a sound signal to be measured between the transmitting piezoelectric transducer 17 and the receiving piezoelectric transducer 18; the receiving piezoelectric transducer 18 is used to convert the sound signal to be measured into an electrical signal.

[0036] It should also be noted that the sound signal propagates in the air by squeezing the air, and the sound propagation will cause the sound pressure at each point in the air to be different, and the different sound pressures will cause the electrical signal converted by the receiving piezoelectric transducer to change in strength; the sound standing wave is formed by the coherent superposition of the incident sound wave and the reflected sound wave, and the formed standing wave makes the sound pressure at each point in the air stable.

[0037] The scale includes a scale body 13, a guide rod 14, a lead screw 15 and a sliding rod 16; the scale body 13, the guide rod 14 and the lead screw 15 are all horizontally arranged between the first support plate 11 and the second support plate 12; wherein, the upper surface of the scale body 13 is provided with scale graduations, the guide rod 14 is located above the side of the scale body 13, and the lead screw 15 is arranged below the side of the scale body 13; wherein, the guide rod 14 and the lead screw 15 are parallel up and down and are located in the same vertical plane, bearing part of the gravity of the sliding rod 16 and not interfering with its sliding on the scale body 13.

[0038] The sliding rod 16 is vertically arranged, and the upper end of the sliding rod 16 is slidably connected to the guiding rod 14; wherein, the sliding direction of the sliding rod 16 is consistent with the axial direction of the guiding rod 14; the middle part of the sliding rod 16 is sleeved on the lead screw 15, and the sliding rod 16 is threadedly connected to the lead screw 15; the lower end of the sliding rod 16 extends below the lead screw 15 and is used for connecting to the schlieren imaging track 21 in the schlieren imaging system 2 to drive the schlieren imaging system 2 to move synchronously with the sliding rod 16; the sliding rod 16 is also used for connecting to the receiving-end piezoelectric transducer 18 and the capacitive grating sensor 19 so that the sliding rod 16, the receiving-end piezoelectric transducer 18 and the capacitive grating sensor 19 move synchronously.

[0039] The capacitive grating sensor 19 is located above the scale and can move synchronously with the receiving-end piezoelectric transducer 18; specifically, the receiving-end piezoelectric transducer 18 is installed at the lower end of the sliding rod 16, and the capacitive grating sensor 19 is arranged on the upper side of the upper end of the sliding rod 16 and on the upper surface of the scale body 13; wherein, the capacitive grating sensor 19 is used for monitoring the position of the receiving-end piezoelectric transducer 18 and outputting position data.

[0040] The output end of the capacitive grating sensor 19 is connected to the first input end of the data collector 111; the input end of the output voltage control circuit 110 is connected to the output end of the receiving-end piezoelectric transducer 18, and the output end of the output voltage control circuit 110 is connected to the second input end of the data collector 111; the first output end of the data collector 111 is connected to the input end of the first display screen 112, and the second output end of the data collector 111 is connected to the input end of the second display screen 113; preferably, both the first display screen 112 and the second display screen 113 adopt LCD display screens; wherein, the first display screen 112 is used for displaying the position data output by the capacitive grating sensor 19, and the second display screen 113 is used for displaying the voltage data output by the output voltage control circuit 110.

[0041] It should be noted that the output voltage control circuit 110 is used for adjusting and stabilizing the electrical signal output by the receiving-end piezoelectric transducer 18 to output a stable voltage signal; wherein, the output voltage control circuit 110 generally includes a voltage regulator and a corresponding feedback mechanism, and its core lies in adjusting the parameters in the circuit by comparing the difference between the actual output voltage and the preset voltage, so as to achieve precise control of the output voltage; preferably, the output voltage control circuit 110 is, for example, a linear voltage regulator circuit or a switching voltage regulator circuit.

[0042] The rotating handwheel 114 is arranged on the outer side of the upper end of the second support plate 12 and is connected to the end of the lead screw 15; wherein, the rotating handwheel 114 is used to drive the lead screw 15 to horizontally rotate around the axis of the lead screw 15, and by driving the rotation of the lead screw 15, the sliding rod 16 is driven to slide along the axis of the guide rod 14.

[0043] As shown in the Figure 4 accompanying drawings, the schlieren imaging system 2 includes a schlieren imaging track 21, a photographing module, a light source module, a connecting gripper 27, a concave mirror 28, a concave mirror base 29, a first roller 210, a second roller 211 and a track telescopic rod 212.

[0044] The schlieren imaging track 21 is horizontally slidably arranged between the first support plate 11 and the second support plate 12, and the axis of the schlieren imaging track 21 is perpendicular to the connection line between the transmitting piezoelectric transducer 17 and the receiving piezoelectric transducer 18; the photographing module, the light source module and the concave mirror 28 are all arranged on the schlieren imaging track 21 for observing the schlieren image of the sound propagation of the to-be-detected sound signal in the air; the connecting gripper 27 is arranged between the schlieren imaging track 21 and the sliding rod 16; wherein, the upper end of the connecting gripper 27 is connected to the lower end of the sliding rod 16, and the lower end of the connecting gripper 27 is fixedly connected to the upper surface of the schlieren imaging track 21.

[0045] The photographing module includes a camera 22 and a camera base 23; the camera base 23 is arranged at the first end of the schlieren imaging track 21, and the camera 22 is installed on the camera base 23; wherein, the camera base 23 is a height-adjustable base, and by installing the camera 22 on the camera base 23, the height of the camera 22 can be adjusted by using the camera base 23.

[0046] The light source module includes a light-emitting light source 24, a blade 25 and a light source lifting platform 26; the light source lifting platform 26 is arranged on the schlieren imaging track 21 and is arranged close to the photographing module side; the light source 24 is arranged on one side of the top end of the light source lifting platform 26, and the blade 25 is arranged on the other side of the top end of the light source lifting platform 26; the concave mirror base 29 is arranged at the second end of the schlieren imaging track 21, and the concave mirror 28 is installed on the concave mirror base 29.

[0047] The first roller 210 is arranged at the bottom end of the camera base 23, and the second roller 211 is arranged at the bottom end of the concave mirror base 29; by arranging the first roller 210 and the second roller 211, the whole schlieren imaging system 2 can be conveniently moved.

[0048] The track telescopic rod 212 is telescopically arranged between the concave mirror base 29 and the second end of the schlieren imaging track 21; wherein, the axis of the track telescopic rod 212 is parallel to the major axis of the schlieren imaging track 21; by arranging the track telescopic rod 212, the distances between the concave mirror 28 and the photographic module and the light source module can be adjusted to meet the adjustment of schlieren imaging under different conditions.

[0049] Working principle and sound speed measurement method:

[0050] When the ultrasonic sound speed measurement device of the present utility model works, the steps are as follows:

[0051] (1) The sound speed measurement process is specifically as follows:

[0052] Step 1: Turn on the signal generator to form a sound standing wave between the transmitting piezoelectric transducer 17 and the receiving piezoelectric transducer 18.

[0053] Step 2: Drive the rotation of the rotating handwheel 14 to drive the lead screw 15 to rotate around its own axis; when the lead screw 15 rotates, drive the receiving piezoelectric transducer 18 and the capacitance grating sensor 19 to slide synchronously along the guide rod 14 through the sliding rod 16; during the synchronous sliding process of the receiving piezoelectric transducer 18 and the capacitance grating sensor 19, use the receiving piezoelectric transducer 18 to collect the voltage data corresponding to the sound signal to be measured during the propagation process in the medium, and send it to the second display screen 113 for display through the output voltage control circuit 110 via the data collector 111; use the capacitance grating sensor 19 to synchronously measure the position of the receiving piezoelectric transducer 18, and then realize the collection of the position data corresponding to different voltage data, and send it to the first display screen 112 for display through the data collector 111.

[0054] When calculating the sound speed of the sound signal to be measured, plot the collected voltage data and position data in the same rectangular coordinate system to obtain a position-voltage curve graph, as shown in the appendix; wherein, the voltage data is used as the vertical axis (y-axis), and the position data is used as the horizontal axis (x-axis); by collecting the abscissas of the preset measurement points on both sides of the peaks of two adjacent curves, four adjacent threshold measurement points are obtained, and based on the four adjacent threshold measurement points, the wavelength of the sound signal to be measured can be obtained; finally, through the calculation relationship between the sound speed and the wavelength, the sound speed of the sound signal to be measured can be obtained. Figure 5 as shown; wherein, the voltage data is used as the vertical axis ( V y-axis), and the position data is used as the horizontal axis ( x x-axis); by collecting the abscissas of the preset measurement points on both sides of the peaks of two adjacent curves, four adjacent threshold measurement points are obtained, and based on the four adjacent threshold measurement points, the wavelength of the sound signal to be measured can be obtained; finally, through the calculation relationship between the sound speed and the wavelength, the sound speed of the sound signal to be measured can be obtained.

[0055] It should be noted that during the process of the receiving piezoelectric transducer 18 moving away from the transmitting piezoelectric transducer 17, due to the energy loss of the sound signal in the air, the electrical signal converted by the receiving piezoelectric transducer 18 also attenuates accordingly. The relationship between the voltage of the electrical signal and the position change is as shown in the appendix Figure 5 ; among them, the position of the voltage antinode corresponds to the position of the sound standing wave node, and the distance between adjacent nodes is half a wavelength. During the measurement, the position coordinates of the nodes are calculated by measuring the two position coordinates adjacent to the same threshold voltage, so as to obtain the wavelength of the sound.

[0056] Specifically, the process of collecting the abscissas of the preset measurement points on both sides of the peaks of two adjacent curves is as follows:

[0057] Determine the threshold voltage according to the upper and lower limits of the voltage data; determine the two threshold measurement points of the first curve peak according to the threshold voltage and , and determine the two threshold measurement points of the second curve peak and ; at this time, the abscissa values of the two antinode points are respectively and ; then, the calculation formula for the wavelength of the sound signal to be measured is specifically:

[0058]

[0059] Among them, and are respectively the two threshold measurement points of the first curve peak; and are respectively the two threshold measurement points of the second curve peak; is the wavelength of the sound signal to be measured.

[0060] (3) The schlieren imaging process is specifically as follows:

[0061] Adjust the photographic module, light source module and concave mirror in the schlieren imaging system 2 so as to observe a clear sound schlieren image in the camera 22; then, drive the rotary handwheel 114 to rotate so that the schlieren imaging system 2 moves synchronously with the receiving piezoelectric transducer 18, and then observe the schlieren images of sound waves at different points in the camera 22.

[0062] Specifically, install the light-emitting light source 24 at the top of the light source lifting platform 26, and set the blade 25 on the other side of the top of the light source lifting platform 26 to ensure that the camera 22, the light-emitting light source 24, and the concave mirror 28 are on the same horizontal line; synchronously move the light-emitting light source 24 and the camera 22 until a complete aperture is displayed on the concave mirror 28 to ensure that the light is fully presented in the camera 22; after ensuring that the aperture covers the concave mirror 28 displayed by the camera 22, fix the camera 22; adjust the focus, brightness, contrast, and sensitivity parameters of the camera 22 to make the schlieren image clear; at this time, observe and record the schlieren imaging situation in the camera 22.

[0063] In the present utility model, by setting up the schlieren imaging system 2, observe the schlieren image of the standing sound wave generated between the transmitting piezoelectric transducer 17 and the receiving piezoelectric transducer 18. During the observation, adjust the concave mirror base 29, the light source lifting platform 26, and the camera base 23 so that the optical axes of the concave mirror 28, the light-emitting light source 24, the blade 25, and the camera 22 are on the same line until a clear schlieren image is seen in the camera 22 to help the measurer more intuitively understand the propagation of sound and the formed standing wave, and realize the visualization of the measurement.

[0064] The ultrasonic sound velocity measuring device described in the present utility model can be directly obtained by transforming the original ultrasonic measuring instrument device. The specific structure is simple, the cost is low, and there is no need for cumbersome calibration to ensure the accuracy of the sound velocity measurement result; at the same time, the measuring device can be extended to the sound velocity measurement in liquids and the liquid bulk modulus, and has a wide range of applications.

[0065] The above embodiments are only one of the implementation manners capable of realizing the technical solution of the present utility model. The scope of protection required by the present utility model is not only limited by this embodiment, but also includes any changes, substitutions, and other implementation manners that are easily conceivable by those skilled in the art within the technical scope disclosed by the present utility model.

Claims

1. An ultrasonic sound velocity measuring device, characterized in that, It includes a signal generator, a capacitive grating ranging system (1) and a schlieren imaging system (2); the signal generator is used to generate a sound signal to be measured in the capacitive grating ranging system (1), and the capacitive grating ranging system (1) includes a first support plate (11), a second support plate (12), a scale, a transmitting piezoelectric transducer (17), a receiving piezoelectric transducer (18), a capacitive grating sensor (19) and a data collector (111). The first support plate (11) and the second support plate (12) are vertically parallel and spaced apart, and the scale is horizontally arranged between the first support plate (11) and the second support plate (12); the transmitting piezoelectric transducer (17) is arranged on the inner side of the first support plate (11) and is located below the end of the scale; the receiving piezoelectric transducer (18) is slidably arranged on the scale and is arranged opposite to the transmitting piezoelectric transducer (17). Wherein, the sound signal to be measured can generate a sound standing wave between the transmitting piezoelectric transducer (17) and the receiving piezoelectric transducer (18); the capacitive grating sensor (19) is located above the scale and can move synchronously with the receiving piezoelectric transducer (18); the output ends of the receiving piezoelectric transducer (18) and the capacitive grating sensor (19) are both connected to the input end of the data collector (111). The schlieren imaging system (2) is arranged between the first support plate (11) and the second support plate (12) and is located between the transmitting piezoelectric transducer (17) and the receiving piezoelectric transducer (18); wherein, the schlieren imaging system (2) can move synchronously with the receiving piezoelectric transducer (18), and the schlieren imaging system (2) is used to observe the schlieren image of the sound propagation of the sound signal to be measured in the air.

2. The ultrasonic sound velocity measuring device according to claim 1, characterized in that The scale includes a scale body (13), a guide rod (14), a lead screw (15) and a sliding rod (16); the scale body (13), the guide rod (14) and the lead screw (15) are all horizontally arranged between the first support plate (11) and the second support plate (12); wherein, the guide rod (14) is located on the upper side of the scale body (13), the lead screw (15) is arranged on the lower side of the scale body (13), and the guide rod (14) and the lead screw (15) are located in the same vertical plane. The upper end of the sliding rod (16) is slidably connected to the guide rod (14), the middle part of the sliding rod (16) is sleeved on the lead screw (15), and the lower end of the sliding rod (16) extends below the lead screw (15); wherein, the sliding rod (16) is threadedly connected to the lead screw (15); the receiving piezoelectric transducer (18) is installed at the lower end of the sliding rod (16), and the capacitive grating sensor (19) is arranged on the upper side of the upper end of the sliding rod (16) and is located on the upper surface of the scale body (13).

3. The ultrasonic sound velocity measuring device according to claim 1, characterized in that, The capacitive grating ranging system (1) further includes an output voltage control circuit (110), a first display screen (112), and a second display screen (113). The input end of the output voltage control circuit (110) is connected to the output end of the receiving piezoelectric transducer (18), and the output end of the output voltage control circuit (110) is connected to the input end of the data collector (111). The first output end of the data collector (111) is connected to the input end of the first display screen (112), and the second output end of the data collector (111) is connected to the input end of the second display screen (113).

4. The ultrasonic sound velocity measuring device according to claim 2, wherein The capacitive grating ranging system (1) further includes a rotating handwheel (114). The rotating handwheel (114) is arranged on the outer side of the upper end of the second support plate (12) and is connected to the end of the lead screw (15). Among them, the rotating handwheel (114) is used to drive the lead screw (15) to horizontally rotate around the axis of the lead screw (15).

5. An ultrasonic sound velocity measuring device according to claim 2, characterized in that, The schlieren imaging system (2) includes a schlieren imaging track (21), a photographic module, a light source module, a connecting gripper (27), and a concave mirror (28). The schlieren imaging track (21) is horizontally slidably arranged between the first support plate (11) and the second support plate (12), and the axis of the schlieren imaging track (21) is perpendicular to the line connecting the transmitting piezoelectric transducer (17) and the receiving piezoelectric transducer (18). The photographic module, the light source module, and the concave mirror (28) are all arranged on the schlieren imaging track (21) for observing the sound schlieren image. The connecting gripper (27) is arranged between the schlieren imaging track (21) and the sliding rod (16). Among them, the upper end of the connecting gripper (27) is connected to the lower end of the sliding rod (16), and the lower end of the connecting gripper (27) is fixedly connected to the upper surface of the schlieren imaging track (21).

6. The ultrasonic sound velocity measuring device according to claim 5, characterized in that The photographic module includes a camera (22) and a camera base (23). The camera base (23) is arranged at the first end of the schlieren imaging track (21), and the camera (22) is installed on the camera base (23). Among them, the camera base (23) is a height-adjustable base.

7. An ultrasonic sound velocity measuring device according to claim 5, characterized in that The light source module includes a light-emitting light source (24), a blade (25), and a light source lifting platform (26). The light source lifting platform (26) is arranged on the schlieren imaging track (21) and is arranged close to the side of the photographic module. The light source (24) is arranged on one side of the top end of the light source lifting platform (26), and the blade (25) is arranged on the other side of the top end of the light source lifting platform (26).

8. An ultrasonic sound velocity measuring device according to claim 6, characterized in that, The schlieren imaging system (2) further includes a concave mirror base (29). The concave mirror base (29) is arranged at the second end of the schlieren imaging track (21), and the concave mirror (28) is installed on the concave mirror base (29).

9. An ultrasonic sound velocity measuring device according to claim 8, characterized in that, The schlieren imaging system (2) further includes a first roller (210) and a second roller (211); the first roller (210) is disposed at the bottom end of the camera base (23), and the second roller (211) is disposed at the bottom end of the concave mirror base (29).

10. An ultrasonic sound velocity measuring device according to claim 8, characterized in that, The schlieren imaging system (2) further includes a track telescopic rod (212); the track telescopic rod (212) is telescopically disposed between the concave mirror base (29) and the second end of the schlieren imaging track (21); wherein, the axis of the track telescopic rod (212) is parallel to the major axis of the schlieren imaging track (21).

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