Probe for bolt ultrasonic nondestructive testing, nondestructive testing device and method

Abstract

The invention belongs to the technical field of ultrasonic non-destructive testing, and provides a probe for bolt ultrasonic non-destructive testing and a non-destructive testing device and method.The probe is characterized in that a lead column is arranged between a wafer shell and a cable box, a filter amplifier is arranged in the cable box, and one end of a lead is connected with the filter amplifier; the piezoelectric wafer is directly connected with the cable box through the lead, the problem that the number of noise signals is large due to factors such as the structures of the conductive screw and the lug plate and the instability of connection between the conductive screw and other shells is solved, the lead column protects the lead, the stability of the lead is improved, and the service life of the lead is prolonged. Noise influence caused by instability of the lead is avoided to a certain extent, the filter amplifier is arranged in the cable box to filter signals transmitted by the lead, influence of noise signals on later data processing precision is further reduced, and bolt stress detection precision is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic nondestructive testing, and in particular relates to a probe, a nondestructive testing device and a method for ultrasonic nondestructive testing of bolts. Background Art

[0002] Bolts, as a key fastener, are widely used in the industrial field. However, they also face problems such as loosening and breaking, which seriously affect economic security. Ultrasonic method is one of the most effective methods for detecting bolt stress. At present, the accuracy of ultrasonic bolt stress detection is limited, and it is difficult to achieve high accuracy, and the process of engineering application is slow.

[0003] The inventors have found that one of the main reasons for the limited accuracy of ultrasonic bolt stress detection is that in the current probes for ultrasonic non-destructive testing of bolts, the structure for receiving the piezoelectric chip signal is that after the piezoelectric chip is connected to the lead, the lead is then connected to an external receiver and processor through a conductive screw and a wiring lug arranged inside the probe; due to the difference between the conductive screw and the wiring lug themselves and the lead when transmitting signals, as well as the instability of the connection between the conductive screw and other housings, more noise signals are added during the signal transmission process, thereby affecting the processing accuracy of the subsequent data and the detection accuracy of the bolt stress, thereby causing engineering safety problems; and unlike the wide pulse and high resolution required by traditional ultrasonic probes, ultrasonic detection of bolts requires narrow pulses, high penetration and high sensitivity, so traditional ultrasonic probes are not well suited for ultrasonic detection of bolts. Summary of the invention

[0004] In order to solve the above problems, the present invention proposes a probe, a nondestructive testing device and a method for ultrasonic nondestructive testing of bolts. A lead post is arranged between the chip shell and the cable box, a filter amplifier is arranged in the cable box, one end of the lead is connected to the filter amplifier, and the other end is directly connected to the piezoelectric chip after passing through the lead post. The lead directly connects the piezoelectric chip and the cable box, avoiding the problem of more noise signals caused by factors such as the structure of the conductive screw and the wiring piece itself and the instability of the connection between the conductive screw and other shells. The protection of the lead by the lead post improves the stability of the lead, and to a certain extent avoids the noise influence caused by the instability of the lead itself.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a probe for ultrasonic nondestructive testing of bolts, which adopts the following technical solution:

[0006] A probe for ultrasonic nondestructive testing of bolts, comprising a housing, a wafer shell arranged at one end of the housing, and a cable box arranged at the other end of the housing;

[0007] A piezoelectric chip is arranged at one end of the chip shell away from the cable box, a lead post is arranged between the chip shell and the cable box, and a filter amplifier is arranged in the cable box; a lead is arranged in the cable box, one end of the lead is connected to the filter amplifier, and the other end is connected to the piezoelectric chip after passing through the lead post; a damping block is arranged between the piezoelectric chip and the bottom of the chip shell, and the damping block is made of epoxy resin and ceramic powder.

[0008] Furthermore, the lead post is a tubular structure, one end of the lead post passes through the outer shell and is connected to the cable box, and the other end passes through the wafer shell and is connected to the damping block; the lead is located inside the lead post.

[0009] Furthermore, a boss is provided inside the shell, and the lead post is connected to the cable box via the boss.

[0010] Furthermore, a transition section is arranged outside the wafer shell, and the wafer shell is connected to the inner wall of the outer shell through the transition section.

[0011] Furthermore, the outer shell is made of metal, and the wafer shell is made of polyvinyl chloride.

[0012] Furthermore, the shell is provided with a plurality of raised stripes at equal intervals.

[0013] Furthermore, a protective film is arranged on the piezoelectric chip, and the protective film is made of corundum; the opening of the chip shell is arranged as an inclined opening, and the protective film is arranged at the inclined opening.

[0014] Furthermore, the filter amplifier includes multiple filter circuits and amplifier circuits connected to the multiple filter circuits; a switch and an acquisition circuit are arranged between each filter circuit and the amplifier circuit, and all switches and acquisition circuits are connected to a preset processor and controller; before detection, the processor determines the filter circuit with the best filtering effect among the multiple filter circuits based on the collected signals, and connects it to the amplifier circuit by controlling the closing of the corresponding switch, while other switches are not closed.

[0015] In order to achieve the above-mentioned purpose, in a second aspect, the present invention also provides an ultrasonic nondestructive testing device for bolts, which adopts the following technical solution:

[0016] A bolt ultrasonic nondestructive testing device adopts the bolt ultrasonic nondestructive testing probe as described in the first aspect.

[0017] In order to achieve the above-mentioned purpose, in a third aspect, the present invention also provides a method for ultrasonic nondestructive testing of bolts, which adopts the following technical solution:

[0018] A method for ultrasonic nondestructive testing of bolts adopts the ultrasonic nondestructive testing device for bolts as described in the first aspect, including: using a piezoelectric chip to collect ultrasonic signals of the bolts, transmitting the ultrasonic signals to a filter amplifier through a lead wire for filtering and amplifying processing, processing the ultrasonic signals after filtering and amplifying processing, and obtaining a detection result.

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

[0020] In the present invention, a lead post is arranged between the chip shell and the cable box, a filter amplifier is arranged in the cable box, one end of the lead is connected to the filter amplifier, and the other end is directly connected to the piezoelectric chip after passing through the lead post. The lead directly connects the piezoelectric chip and the cable box, avoiding the problem of more noise signals caused by factors such as the structure of the conductive screw and the wiring piece itself and the instability of the connection between the conductive screw and other shells. The lead post protects the lead, improves the stability of the lead, and avoids the noise influence caused by the instability of the lead itself to a certain extent. The filter amplifier is arranged in the cable box to filter the signal transmitted by the lead, further reducing the influence of the noise signal on the accuracy of subsequent data processing, and ensuring the detection accuracy of the bolt stress; at the same time, the damping block uses low-damping epoxy resin and ceramic powder, which prolongs the vibration time of the probe, improves the penetration of the probe, and further improves the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0022] Figure 1 A schematic diagram of the probe structure of an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of surface stripes of a probe according to an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of a filter amplifier according to an embodiment of the present invention;

[0025] Among them, 1. outer shell; 2. lead column; 3. damping block; 4. piezoelectric chip; 5. cable box; 6. chip shell; 7. lead; 8. protective film; 9. stripes; 10. boss; 11. transition section; 12. inclined mouth. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0028] As an advanced industrial flaw detection technology, ultrasonic nondestructive testing technology is widely used in energy, construction, transportation, aerospace, materials and other fields. Ultrasonic nondestructive testing technology is to characterize the object under test based on the propagation state of ultrasonic waves in the object under test. Ultrasonic technology not only has the characteristics of good directionality, strong penetration, wide application range and high efficiency, but also can realize non-destructive testing of metal materials, non-metallic materials and composite materials. As a typical ultrasonic equipment, ultrasonic stress detector plays an irreplaceable role in stress detection, defect identification and ultrasonic thickness measurement.

[0029] The key to improving the detection efficiency is to reasonably select ultrasonic probes during ultrasonic testing, which mainly includes the selection of probe type, frequency, chip size, K value, probe bandwidth and other parameters. The selection of probe parameters in different working conditions determines the effect and quality of ultrasonic testing.

[0030] Bolts are a key fastener and are widely used in the industrial field. However, they also face problems such as loosening and breaking, which seriously affect economic security. Ultrasonic method is one of the most effective methods for detecting bolt stress. At present, the accuracy of ultrasonic bolt stress detection is limited, and it is difficult to achieve high accuracy, and the process of engineering application is slow.

[0031] As described in the background technology, in the current probe for ultrasonic non-destructive testing of bolts, the structure for receiving the piezoelectric chip signal is that after the piezoelectric chip is connected to the lead, the lead is then connected to an external receiver and processor through a conductive screw and a wiring piece arranged inside the probe; due to the difference between the conductive screw and the wiring piece's own structure and the lead when transmitting signals, as well as the instability of the connection between the conductive screw and other housings, more noise signals will be added during the signal transmission process, thereby affecting the processing accuracy of the subsequent data and the detection accuracy of the bolt stress, thereby causing engineering safety problems.

[0032] In response to the above problems, Figure 1 and Figure 2As shown, a probe for ultrasonic nondestructive testing of bolts is provided, comprising a housing 1, a lead post 2, a damping block 3, a piezoelectric chip 4, a cable box 5, a chip shell 6, a lead 7, a protective film 8, and a raised stripe 9. The housing 1, as a supporting material for the probe shell, can be made of stainless steel; the chip shell 6 is placed inside the housing 1, with the upper end clamped on the lead post 2, and the lower end clamped on the two ends of the damping block 3 and the piezoelectric chip 4; the damping block 3 is placed in a closed cavity surrounded by the chip shell 6, the lead post 2, and the piezoelectric chip 4; the upper end of the lead post 2 is clamped in the middle of the housing 1, and the lower end is clamped in the middle of the chip shell 6, the cable box 5 is placed on the upper part of the lead post 2, and a digital signal filtering and amplifying circuit is installed inside; the piezoelectric chip 4 and the protective film 8 are located on the outer side of the probe, and the upper end of the piezoelectric chip 4 is connected to the damping block 3, and the protective film 8 is placed on the outer side of the piezoelectric chip 4 and covers the surface of the piezoelectric chip 4.

[0033] Optionally, a piezoelectric chip 4 is arranged at one end of the chip shell 6 away from the cable box 5, a lead column 2 is arranged between the chip shell 6 and the cable box 5, and a filter amplifier is arranged in the cable box 5; a lead 7 is arranged in the cable box 5, one end of the lead 7 is connected to the filter amplifier, and the other end is connected to the piezoelectric chip 4 after passing through the lead column 2; a damping block 3 is arranged between the piezoelectric chip 4 and the bottom of the chip shell 6, and the damping block 3 is made of epoxy resin and ceramic powder. Specifically, the lead post 2 is arranged between the chip shell 6 and the cable box 5, and a filter amplifier is arranged in the cable box 5. One end of the lead 7 is connected to the filter amplifier, and the other end is directly connected to the piezoelectric chip 4 after passing through the lead post 2. The lead 7 directly connects the piezoelectric chip 4 and the cable box 5, avoiding the problem of more noise signals caused by factors such as the structure of the conductive screw and the wiring piece itself and the instability of the connection between the conductive screw and other shells. The lead post 2 protects the lead 7, improves the stability of the lead 7, and avoids the instability of the lead 7 itself to a certain extent. In order to reduce the influence of noise, a filter amplifier is arranged in the cable box 5 to filter the signal transmitted by the lead 7, thereby further reducing the influence of the noise signal on the accuracy of subsequent data processing and ensuring the detection accuracy of bolt stress; the probe abandons the conductive screw and the wiring piece of the traditional probe, and adopts the design idea that the lead 7 is directly connected to the cable box 5, thereby reducing the noise signal caused by the matching and impedance problems of the conductive screw and the wiring piece. The signal is directly connected to the cable box 5 through the lead 7, and then the signal is further integrated through the digital signal filter amplifier in the cable box 5, thereby improving the signal-to-noise ratio of the probe.

[0034] In some embodiments, the damping block 3 is selected with low-damping epoxy resin and ceramic powder. Optionally, the epoxy resin and ceramic powder are directly filled into the position where the damping block 3 is located, and the ratio of the epoxy resin and the ceramic powder can be adjusted according to actual needs; the damping block 3 is selected with low-damping epoxy resin and ceramic powder, which prolongs the vibration time of the probe, improves the penetration of the probe, and further improves the detection accuracy.

[0035] In some embodiments, optionally, the lead post 2 is a tubular structure, one end of the lead post 2 passes through the outer shell 1 and is connected to the cable box 5, and the other end passes through the chip shell 6 and is connected to the damping block 3; the lead 7 is located inside the lead post 2; the lead 7 is located inside the lead post 2, and one end of the lead post 2 passes through the outer shell 1 and is directly connected to the cable box 5, and the other end passes through the chip shell 6, thereby ensuring the stability of the environment of the lead 7 in the lead post 2 and reducing the generation of noise signals.

[0036] In some embodiments, optionally, the boss 10 is provided inside the housing 1, and the lead post 7 is connected to the cable box 5 via the boss 10. Specifically, the boss 10 is provided inside the housing 1, and the lead post 2 is connected to the cable box 5 via the boss 10, which improves the fixing stability of the lead post 2, avoids the vibration frequency of the lead post 2, further ensures the stability of the lead 7 inside the lead post 2, and reduces the generation of noise signals.

[0037] In some embodiments, optionally, a transition section 11 is provided outside the wafer shell 6, and the wafer shell 6 is connected to the inner wall of the outer shell 1 through the transition section 11. Specifically, the transition section 11 is provided between the wafer shell 6 and the outer shell 1, and the size of the piezoelectric wafer 4 is reduced on the basis of ensuring the overall probe specifications, and the sensitivity of the probe is improved. At the same time, the reduction in the size of the piezoelectric wafer 4 reduces the interference of the clutter signal on the echo signal, avoids the acoustic time error caused by the superposition of a large number of clutter signals, and improves the acoustic time accuracy of the echo signal.

[0038] In some embodiments, the shell 1 is made of metal, and the wafer shell 6 is made of polyvinyl chloride; the shell 1 is provided with a plurality of equally spaced raised stripes 9; the shell 1 is made of metal, and the surface is provided with raised stripes 9, which is suitable for use in extreme environments such as humidity and high temperature; the wafer shell 6 is made of polyvinyl chloride, and the insulating properties of the polyvinyl chloride material are used to isolate the electromagnetic interference effects of other parts, ensure signal accuracy, and reduce density and weight. Optionally, the shell 1 is made of stainless steel, such as 304 stainless steel, which improves durability and ensures the service life of the probe. The surface of the shell 1 is covered with 12 raised stripes 9 with a spacing of 2 mm, which is suitable for use in extreme environments such as humidity and high temperature. The wafer shell 6 is made of PVC, and the excellent insulating properties of the PVC material isolate the electromagnetic interference effects of other parts, and reduce density and weight; the lead column overcomes the noise pollution problem caused by the combination of the wiring piece and the conductive column in the traditional probe.

[0039] In some embodiments, optionally, a protective film 8 is provided on the piezoelectric wafer 4, and the protective film 8 is made of corundum; the opening of the wafer shell 6 is provided with an inclined opening 12, and the protective film 8 is provided at the inclined opening 12. Specifically, the protective film 8 is made of corundum, which has a low friction coefficient, excellent anti-fouling ability and heat dissipation, to ensure the durability and stability of the probe during use; the provision of the inclined opening 12 increases the contact area between the protective film 8 and the outside world, and minimizes the impact and pollution of the outside world on the piezoelectric wafer.

[0040] When inspecting bolts in different environments and engineering fields, the different environments and field conditions result in different noises in the acquired signals. If a fixed filter circuit is used, the ultrasonic signal may not be filtered well in some environments, resulting in reduced accuracy of the inspection results. To solve this problem, in some embodiments, it is optional, such as Figure 3 As shown, the filter amplifier includes multiple filter circuits and amplifier circuits connected to the multiple filter circuits; switches and acquisition circuits are arranged between each filter circuit and the amplifier circuit, and all switches and acquisition circuits are connected to a preset processor and controller; before detection, the processor determines the filter circuit with the best filtering effect among the multiple filter circuits according to the collected signals, and controls the corresponding switches to be closed and connected to the amplifier circuit, while other switches are not closed, so that the optimal filter circuit can be determined according to different detection environments; the filter circuits include but are not limited to low-pass filter circuits, high-pass filter circuits, band-pass filter circuits and all-pass filter circuits.

[0041] The above-mentioned ultrasonic non-destructive testing probe for bolts is designed to be a high-penetration and high-sensitivity special probe for bolts by optimizing the probe structure and selecting special materials, which ensures the accuracy and precision of sound-time measurement, overcomes the shortcomings of high damping, narrow pulse and low sensitivity of traditional probes, realizes the probe's specific detection of bolts, provides technical reserves for high-precision measurement of bolt tightening force, and accelerates the engineering application of ultrasonic non-destructive testing in bolt detection.

[0042] In some embodiments, based on the provided ultrasonic non-destructive testing probe for bolts, a bolt ultrasonic non-destructive testing device is also provided. The signal reception and processing of the non-destructive testing device can be achieved through conventional technologies and will not be described in detail here.

[0043] In some embodiments, based on the provided ultrasonic nondestructive testing probe and nondestructive testing device for bolts, a method for ultrasonic nondestructive testing of bolts is also provided, including: using a piezoelectric chip 4 to collect ultrasonic signals of the bolts, transmitting the ultrasonic signals to a filter amplifier through a lead 7 for filtering and amplifying processing, and processing the ultrasonic signals after filtering and amplifying processing to obtain a detection result.

[0044] In some embodiments, in implementing the method for ultrasonic nondestructive testing of bolts, a method for calculating ultrasonic zero offset of bolts is also provided based on a special probe for ultrasonic nondestructive testing of bolts, including the following steps:

[0045] S1. Take a number of bolts to be tested and place them on the test bench.

[0046] S2. Use a wire to connect the special probe and the ultrasonic stress detector, and place the special probe on the end of the bolt to be tested through a coupling agent. Optionally, after the probe is placed on the end of the bolt through the coupling agent, let it stand for 3 to 5 minutes, and then debug the ultrasonic stress detector after the probe and the bolt are fully coupled.

[0047] S3. Turn on the ultrasonic stress detector and debug the program.

[0048] The in-service bolt stress detection device is used to debug the program, and an ultrasonic stress detector is used to record the longitudinal wave primary echo signal and the secondary echo signal under zero stress of the bolt to be tested; optionally, the longitudinal wave primary echo signal and the secondary echo signal both read the indication value of the highest wave.

[0049] S4. Use the following formula to calculate zero bias:

[0050] T0=2T1-T2

[0051] Where, T1 and T2 are the acoustic times of the ultrasonic stress detector corresponding to the primary and secondary echoes of the longitudinal wave, respectively; T0 is the zero bias.

[0052] The provided ultrasonic zero bias calculation method and the provided probe overcome the experimental error brought by the traditional ultrasonic probe to the greatest extent. Under the premise of ensuring wide pulse and high sensitivity, the value of the ultrasonic echo signal of the bolt can be accurately measured. The zero bias is obtained through the calculation formula, which greatly improves the accuracy of traditional ultrasonic detection. The designed probe improves the sensitivity of acoustic time measurement, thereby further improving the stress state monitoring of in-service bolts.

[0053] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A probe for ultrasonic nondestructive testing of bolts, characterized in that: It comprises a housing, a wafer shell arranged at one end of the housing, and a cable box arranged at the other end of the housing; A piezoelectric chip is arranged at one end of the chip shell away from the cable box, a lead post is arranged between the chip shell and the cable box, and a filter amplifier is arranged in the cable box; a lead is arranged in the cable box, one end of the lead is connected to the filter amplifier, and the other end is connected to the piezoelectric chip after passing through the lead post; a damping block is arranged between the piezoelectric chip and the bottom of the chip shell, and the damping block is made of epoxy resin and ceramic powder.

2. A probe for ultrasonic nondestructive testing of bolts as claimed in claim 1, characterized in that: The lead post is a tubular structure, one end of the lead post passes through the outer shell and is connected to the cable box, and the other end passes through the wafer shell and is connected to the damping block; the lead wire is located inside the lead post.

3. The ultrasonic nondestructive testing probe for bolts according to claim 1, characterized in that: A boss is arranged inside the shell, and the lead post is connected to the cable box via the boss.

4. The ultrasonic nondestructive testing probe for bolts according to claim 1, characterized in that: A transition section is arranged outside the wafer shell, and the wafer shell is connected to the inner wall of the outer shell through the transition section.

5. The ultrasonic nondestructive testing probe for bolts according to claim 1, characterized in that: The outer shell is made of metal, and the wafer shell is made of polyvinyl chloride.

6. A probe for ultrasonic nondestructive testing of bolts as claimed in claim 5, characterized in that: The shell is provided with a plurality of convex stripes with equal intervals.

7. The probe for ultrasonic nondestructive testing of bolts according to claim 1, characterized in that: A protective film is arranged on the piezoelectric chip, and the protective film is made of corundum; the opening of the chip shell is arranged as an inclined opening, and the protective film is arranged at the inclined opening.

8. The ultrasonic nondestructive testing probe for bolts according to claim 1, characterized in that: The filter amplifier includes multiple filter circuits and amplifier circuits connected to the multiple filter circuits; a switch and an acquisition circuit are arranged between each filter circuit and the amplifier circuit, and all switches and acquisition circuits are connected to a preset processor and controller; before detection, the processor determines the filter circuit with the best filtering effect among the multiple filter circuits based on the collected signals, and connects it to the amplifier circuit by controlling the closing of the corresponding switch, while other switches are not closed.

9. A bolt ultrasonic nondestructive testing device, characterized in that: A probe for ultrasonic nondestructive testing of bolts as described in any one of claims 1 to 8 is used.

10. A method for ultrasonic nondestructive testing of bolts, using the ultrasonic nondestructive testing device for bolts as claimed in claim 9, comprising: The ultrasonic signal of the bolt is collected by using a piezoelectric chip. The ultrasonic signal is transmitted to the filter amplifier through the lead wire for filtering and amplification processing. The ultrasonic signal after filtering and amplification processing is processed to obtain the detection result.

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