A multi-chip contact type ultrasonic probe for detecting liquid level height

Abstract

The present invention relates to a multi-chip contact-type ultrasonic probe for detecting liquid level height, comprising an inclined wedge, a piezoelectric chip, a damping block, a housing, and lead wires. The inclined wedge, piezoelectric chip, and damping block are all located within the housing, the piezoelectric chip being mounted on the inclined wedge, and the damping block being mounted on the piezoelectric chip. One end of the lead wire is connected to the piezoelectric chip, and the other end is connected to an opening of the housing. Three inclined wedges, three piezoelectric chips, and three damping blocks are provided, wherein the three piezoelectric chips are of different models: a first piezoelectric chip is mounted on a first inclined wedge, a second piezoelectric chip is mounted on a second inclined wedge, and a third piezoelectric chip is mounted on a third inclined wedge. The first damping block is mounted on the first piezoelectric chip, the second damping block is mounted on the second piezoelectric chip, and the third damping block is mounted on the third piezoelectric chip. Compared with the prior art, the present invention has the advantages of being applicable to containers with different bottom wall thicknesses for liquid level measurement.

Description

Technical Field

[0001] The present invention relates to an ultrasonic probe, in particular to a multi-chip contact type ultrasonic probe for detecting liquid level height. Background Art

[0002] Ultrasonic probes can be used in a variety of applications, including thickness measurement, defect detection, and distance detection. The probes acquire voltage signals through transmitting and receiving units and use the time difference between the transmitted and received signals and the voltage amplitude to identify parameters such as thickness, defects, and distance. The basic structure of a probe can be divided into a piezoelectric chip, a damping block, sound-absorbing material, a wedge, a housing, and lead wires.

[0003] However, when measuring the liquid level in a container, current ultrasonic probes generally use single-crystal probes or polycrystalline probes of the same model and specifications. Therefore, they are applicable to a single container bottom wall thickness and cannot measure the liquid level of containers with different bottom wall thicknesses, limiting the scope of application. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-chip contact-type ultrasonic probe for detecting liquid level height. By designing three piezoelectric chips, since the penetration capabilities of piezoelectric chips of different models and specifications are different, it can be applied to containers with different bottom wall thicknesses to measure the liquid level. Compared with the traditional top-down measurement method, it is more convenient to use and has a higher accuracy.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A multi-chip contact-type ultrasonic probe for detecting liquid level height includes an inclined wedge, a piezoelectric chip, a damping block, a housing, and a lead wire. The inclined wedge, piezoelectric chip, and damping block are all located in the housing. The piezoelectric chip is arranged on the inclined wedge, and the damping block is arranged on the piezoelectric chip. One end of the lead wire is connected to the piezoelectric chip, and the other end is connected to the opening of the housing. There are three inclined wedges, three piezoelectric chips, and three damping blocks. The three piezoelectric chips are of different models. The first piezoelectric chip is arranged on the first inclined wedge, the second piezoelectric chip is arranged on the second inclined wedge, and the third piezoelectric chip is arranged on the third inclined wedge. The first damping block is arranged on the first piezoelectric chip, the second damping block is arranged on the second piezoelectric chip, and the third damping block is arranged on the third piezoelectric chip.

[0007] The cross section of the inclined wedge is a sector with an angle of 120 degrees. The cross section of the three inclined wedges combined is a circle. The three piezoelectric chips are rotationally symmetrical, and the rotation center of the rotational symmetry is the center of the circle.

[0008] The highest point of the inclined wedge is located at the center of the circle.

[0009] There are six lead wires in total, which are divided into three groups corresponding to three piezoelectric chips, with two lead wires in each group. One end of the two lead wires in each group is respectively connected to the positive and negative poles of the corresponding piezoelectric chip, and the other end is connected to the opening of the shell.

[0010] All the lead wires connected to the positive electrode of the piezoelectric chip are wrapped into one strand by the insulating wrapping layer, and all the lead wires connected to the negative electrode of the piezoelectric chip are wrapped into one strand by the insulating wrapping layer.

[0011] The shell is filled with sound absorbing material.

[0012] The cross section of the piezoelectric wafer is circular.

[0013] The excitation frequency of the first piezoelectric chip is 200 kHz, the excitation frequency of the second piezoelectric chip is 450 kHz, and the excitation frequency of the third piezoelectric chip is 1200 kHz.

[0014] The damping block is composed of polyether polyurethane, polyurethane and epoxy resin.

[0015] The ultrasonic probe further includes a controller, which is connected to the three piezoelectric wafers respectively and is configured to perform the following steps:

[0016] Control the operation of three piezoelectric chips;

[0017] Receive feedback signals from three piezoelectric chips and analyze them to obtain liquid level values;

[0018] Determine whether the liquid level values ​​corresponding to the three piezoelectric chips are within the preconfigured range. If the liquid level value corresponding to only one piezoelectric chip is within the preconfigured range, the liquid level value is output as a value. If the liquid level values ​​corresponding to multiple piezoelectric chips are within the preconfigured range, the average value of all liquid level values ​​within the preconfigured range is taken and output as the measured value.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. By designing three piezoelectric chips, since the penetration capabilities of piezoelectric chips of different models and specifications are different, it can be applied to containers with different bottom wall thicknesses to measure the liquid level. Compared with the traditional top-down measurement method, it is more convenient to use and has higher accuracy.

[0021] 2. The cross section of the inclined wedge is a 120-degree sector and forms a complete circle with a symmetrical structure, which minimizes the error caused by excessive position difference.

[0022] 3. All positive and negative lead wires are integrated into one, making wiring more convenient in actual use.

[0023] 4. By setting a reasonable wall thickness range as the basis for data screening, fully automatic liquid level value output can be achieved, and the amount of calculation is greatly reduced. A lower performance but more reliable controller can be used to improve reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 Schematic diagram of the distribution of three piezoelectric wafers of the present invention;

[0026] Figure 3 is a schematic diagram of the damping block;

[0027] Wherein: 1. housing, 2. first oblique wedge, 3. first piezoelectric chip, 4. first damping block, 5. lead wire, 6. sound absorbing material, 7. second oblique wedge, 8. second piezoelectric chip, 9. third oblique wedge, 10. third piezoelectric chip. DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0029] A multi-chip contact type ultrasonic probe for detecting liquid level height, such as Figure 1 and Figure 2 As shown, it includes an inclined wedge, a piezoelectric chip, a damping block, a shell 1 and a lead wire 5. The inclined wedge, the piezoelectric chip and the damping block are all located in the shell 1. The piezoelectric chip is arranged on the inclined wedge, and the damping block is arranged on the piezoelectric chip. One end of the lead wire 5 is connected to the piezoelectric chip, and the other end is connected to the opening of the shell 1. There are three inclined wedges, three piezoelectric chips and three damping blocks. Among them, the models of the three piezoelectric chips are different. The first piezoelectric chip 3 is arranged on the first inclined wedge 2, the second piezoelectric chip 8 is arranged on the second inclined wedge 7, and the third piezoelectric chip 10 is arranged on the third inclined wedge 9. The first damping block 4 is arranged on the first piezoelectric chip 3, the second damping block is arranged on the second piezoelectric chip 8, and the third damping block is arranged on the third piezoelectric chip 10.

[0030] By designing three piezoelectric chips, since the penetration capabilities of piezoelectric chips of different models and specifications are different, they can be used to measure the liquid level of containers with different bottom wall thicknesses. Compared with the traditional top-down measurement method, it is more convenient to use and has higher accuracy.

[0031] Specifically, in Figure 1 In order to make the picture clearer, only the first piezoelectric chip 3, the first wedge 2 and the first damping block 4 are shown. Figure 2The figure shows the distribution of three piezoelectric crystals. The cross-section of the wedge is a 120-degree sector, and the combined cross-section of the three wedges is circular. The three piezoelectric crystals are rotationally symmetric, with the center of rotation being the center of the circle. The cross-section of the wedge is a 120-degree sector, forming a complete circle, creating a symmetrical structure that minimizes errors caused by large positional differences. In this embodiment, the highest point of the wedge is located at the center of the circle.

[0032] In this embodiment, there are six lead wires 5, divided into three groups corresponding to the three piezoelectric wafers, with two lead wires in each group. One end of each of the two lead wires 5 is connected to the positive and negative electrodes of the corresponding piezoelectric wafer, respectively, and the other end is connected to the opening of the housing 1. All lead wires 5 connected to the positive electrodes of the piezoelectric wafers are wrapped in an insulating layer as a single strand, while all lead wires 5 connected to the negative electrodes of the piezoelectric wafers are also wrapped in an insulating layer as a single strand. All positive and negative lead wires 5 are combined into a single strand, making wiring more convenient in actual use.

[0033] In addition, the housing 1 is filled with sound absorbing material 6 .

[0034] Specifically, the cross section of the piezoelectric wafer is circular.

[0035] In this embodiment, the first piezoelectric wafer 3, the second piezoelectric wafer 8 and the third piezoelectric wafer 10 are respectively of type 1-3, type 1-3 and type 2-2. They are of the same size and are all cylindrical with a diameter of 14 mm and a height of 5 mm. The parameters of the two piezoelectric wafers are shown in Table 1.

[0036] Table 1

[0037]

[0038] The excitation frequency of the first piezoelectric chip 3 is 200 kHz, the excitation frequency of the second piezoelectric chip 8 is 450 kHz, and the excitation frequency of the third piezoelectric chip 10 is 1200 kHz.

[0039] The wedges are made of plexiglass, and there are three of them. They appear triangular when viewed from the side, with a 30° angle to the horizontal. When viewed from above, they appear fan-shaped, with a central angle of 120° and a radius of 1.5 cm. The wedges are secured to the piezoelectric wafer via a 1.5 mm deep, 14 mm diameter circular hole drilled in the wedges.

[0040] In this embodiment, the damping block is composed of polyether polyurethane, polyurethane and epoxy resin (TDE-85). The length, width and height of the damping block are 14 mm, 14 mm and 5 mm respectively. The epoxy resin is bonded to the piezoelectric chip. The thickness of the epoxy resin is 1 mm, the thickness of the polyether polyurethane is 2.35 mm, and the thickness of the polyurethane is 1.65 mm.

[0041] In this embodiment, the housing 1 is made of aluminum alloy. Sound-absorbing material 6 is located between the bottom of the wedge and the housing 1, as well as in other locations within the housing 1. The sound-absorbing material 6 between the bottom of the wedge and the housing 1 is made of hard fiberboard, primarily for absorbing low-frequency sound signals. It has a resonant frequency of 100-150 Hz and a sound absorption coefficient of 0.3-0.5. The fiberboard weighs 5-20g and is 1-1.5mm thick. The sound-absorbing material 6 in other locations within the housing 1 is made of urethane foam, with a pore size of 0.01mm and a density of 11.3-15g / m 3 .

[0042] The first piezoelectric chip 3 can cover the liquid level test in the container wall with a thickness of 1.0-1.5cm, the second piezoelectric chip 8 can cover the liquid level test in the container wall with a thickness of 0.5-1.0cm, and the third piezoelectric chip 10 can cover the liquid level test in the container wall with a thickness of 0.2-0.5cm. Based on the unknown specific thickness of the container wall, the control method is to apply the excitation signals of the above three frequencies to the positive electrode in turn, and the negative electrode is grounded. The application time is 10 cycles of each excitation frequency, and the interval time is 2s. After receiving the echo signal, the time difference t between the signal and the previous excitation signal is calculated, and then the liquid level height d=vt / 2 is calculated according to the propagation speed v of the ultrasonic wave in the liquid.

[0043] The ultrasonic probe further includes a controller, which is connected to the three piezoelectric crystals respectively and is configured to perform the following steps:

[0044] Control the operation of three piezoelectric chips;

[0045] Receive feedback signals from three piezoelectric chips and analyze them to obtain liquid level values;

[0046] Determine whether the liquid level values ​​corresponding to the three piezoelectric chips are within the preconfigured range. If the liquid level value corresponding to only one piezoelectric chip is within the preconfigured range, the liquid level value is output as a value. If the liquid level values ​​corresponding to multiple piezoelectric chips are within the preconfigured range, the average value of all liquid level values ​​within the preconfigured range is taken and output as the measured value.

[0047] By setting a reasonable wall thickness range as the basis for data screening, fully automatic liquid level value output can be achieved, and the amount of calculation is greatly reduced. A lower performance but more reliable controller can be used to improve reliability.

[0048] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

Claims

1. A multi-chip contact-type ultrasonic probe for detecting liquid level height, comprising an inclined wedge, a piezoelectric chip, a damping block, a housing, and lead wires, wherein the inclined wedge, piezoelectric chip, and damping block are all located within the housing, the piezoelectric chip is disposed on the inclined wedge, and the damping block is disposed on the piezoelectric chip. One end of the lead wire is connected to the piezoelectric chip, and the other end is connected to an opening of the housing, characterized in that: There are three of each of the wedges, piezoelectric wafers, and damping blocks, wherein the three piezoelectric wafers are of different models, the first piezoelectric wafer is arranged on the first wedge, the second piezoelectric wafer is arranged on the second wedge, the third piezoelectric wafer is arranged on the third wedge, the first damping block is arranged on the first piezoelectric wafer, the second damping block is arranged on the second piezoelectric wafer, and the third damping block is arranged on the third piezoelectric wafer; The ultrasonic probe further includes a controller, which is connected to the three piezoelectric wafers respectively and is configured to perform the following steps: Control the operation of three piezoelectric chips; Receive feedback signals from three piezoelectric chips and analyze them to obtain liquid level values; Determine whether the liquid level values ​​corresponding to the three piezoelectric chips are within the preconfigured range. If the liquid level value corresponding to only one piezoelectric chip is within the preconfigured range, the liquid level value is output as a value. If the liquid level values ​​corresponding to multiple piezoelectric chips are within the preconfigured range, the average value of all liquid level values ​​within the preconfigured range is taken and output as the measured value.

2. A multi-chip contact type ultrasonic probe for detecting liquid level according to claim 1, characterized in that: The cross section of the inclined wedge is a sector with an angle of 120 degrees. The cross section of the three inclined wedges combined is a circle. The three piezoelectric chips are rotationally symmetrical, and the rotation center of the rotational symmetry is the center of the circle.

3. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 2, characterized in that: The highest point of the inclined wedge is located at the center of the circle.

4. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 1, characterized in that: There are six lead wires in total, which are divided into three groups corresponding to three piezoelectric chips, with two lead wires in each group. One end of the two lead wires in each group is respectively connected to the positive and negative poles of the corresponding piezoelectric chip, and the other end is connected to the opening of the shell.

5. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 4, characterized in that: All the lead wires connected to the positive electrode of the piezoelectric chip are wrapped into one strand by the insulating wrapping layer, and all the lead wires connected to the negative electrode of the piezoelectric chip are wrapped into one strand by the insulating wrapping layer.

6. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 1, characterized in that: The shell is filled with sound absorbing material.

7. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 1, characterized in that: The cross section of the piezoelectric wafer is circular.

8. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 1, characterized in that: The excitation frequency of the first piezoelectric chip is 200 kHz, the excitation frequency of the second piezoelectric chip is 450 kHz, and the excitation frequency of the third piezoelectric chip is 1200 kHz.

9. The multi-chip contact type ultrasonic probe for detecting liquid level according to claim 1, characterized in that: The damping block is composed of polyether polyurethane, polyurethane and epoxy resin.

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