Square small-section longitudinal wave bicrystal probe for ultrasonic detection of circular arc part of base

Abstract

The utility model discloses a square small cross section longitudinal wave twin-crystal probe for ultrasonic detection of a base arc portion, which comprises a delay block, a sound insulation layer, a probe core, a sound absorption material and piezoelectric crystal plates which are arranged in a shell, the two piezoelectric crystal plates are square, the size of each piezoelectric crystal plate is 4 mm * 2 mm, and the total size is 4 mm * 4 mm. And the working frequency of the longitudinal wave twin-crystal probe is set to be 4MHz. The piezoelectric crystal plates are arranged to be square, the sizes of the two piezoelectric crystal plates are both 4 mm * 2 mm, the sound field directivity of the square piezoelectric crystal plates is better than that of a round piezoelectric crystal plate, the detection sensitivity is high, meanwhile, the piezoelectric crystal plates with small sections are adopted, the problem that coupling between the probe and the surface of a transition arc part of a machine base is poor can be solved, and the detection accuracy is improved. And the working frequency is controlled to be 2-6MHz, so that detection personnel can more accurately position and evaluate defects, and meanwhile, the detection sensitivity is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic detection, in particular to a square small-section longitudinal wave double crystal probe for ultrasonic detection of arc parts of a machine base. Background Art

[0002] The machine base is a large casting product. According to the product technical requirements, ultrasonic flaw detection is required inside the transition arc part at the bottom of the machine base. The following problems exist when using conventional longitudinal wave probes for detection:

[0003] Since the radius of the transition arc at the bottom of the machine base is R40, when a circular straight longitudinal wave probe with a conventional diameter (Φ14mm and above) is used for testing, there will be a problem of poor coupling between the probe and the surface of the transition arc at the machine base (there is a gap between the probe and the contact part of the transition arc at the machine base), resulting in the problem that the ultrasonic wave emitted by the probe cannot be effectively transmitted to the inside of the machine base product, making the test impossible to implement;

[0004] The use of a small diameter (Φ4mm) circular straight longitudinal wave probe for testing has solved the problem of poor surface coupling between the probe and the arc transition area of ​​the machine base. However, due to the large pointing angle of the small diameter (Φ4mm) circular straight longitudinal wave probe, the directivity of the sound field is poor, and the detection sensitivity is low, which cannot meet the product detection requirements;

[0005] Therefore, the present application provides a square small-section longitudinal wave dual-crystal probe for ultrasonic detection of the arc part of the machine base to meet the needs. Utility Model Content

[0006] The purpose of the present application is to provide a square small-section longitudinal wave dual-crystal probe for ultrasonic detection of the arc part of a machine base, so as to solve the existing technical problems.

[0007] To achieve the above-mentioned purpose, the present application provides the following technical solutions: a square small-section longitudinal wave dual crystal probe for ultrasonic detection of the arc part of a machine base, comprising a delay block, a sound insulation layer, a probe core, a sound absorbing material and a piezoelectric chip installed in a shell, the probe core is provided in two groups and is symmetrically arranged on the left and right, the two probe cores are arranged in an eight-shaped shape, the two probe cores are arranged in the installation groove of the sound absorbing material, the sound insulation layer separates the two probe cores, the piezoelectric chips are provided in two groups, and each group of the piezoelectric chips is adapted to the corresponding longitudinal wave probe core, the two piezoelectric chips are both set to a square shape, the dimensions of the two piezoelectric chips are both set to 4mm×2mm, and the total dimension is 4mm×4mm. When working, the working frequency of the longitudinal wave dual crystal probe is set to 2-6MHz.

[0008] As a preferred implementation in this embodiment, the operating frequency of the longitudinal wave dual crystal probe is set to 4 MHz.

[0009] As a preferred implementation in this embodiment, the focal length of the longitudinal wave dual crystal probe is set to 12-19 mm.

[0010] As a preferred implementation in this embodiment, the focal length of the longitudinal wave dual crystal probe is set to 15 mm.

[0011] As a preferred implementation manner in this embodiment, the bottom of the piezoelectric wafer is densely covered with tiny pits.

[0012] As a preferred implementation in this embodiment, the micro-pits are arranged in a regular hexagon.

[0013] In summary, the technical effects and advantages of the utility model are:

[0014] The utility model has a reasonable structure, the piezoelectric chip is set to be square, and the size of the two piezoelectric chips is set to 4mm×2mm. The sound field directivity of the square piezoelectric chip is better than that of the circular piezoelectric chip, and the detection sensitivity is high. At the same time, the piezoelectric chip with a small cross-section can solve the problem of poor surface coupling between the probe and the transition arc part of the base, and the operating frequency is controlled to be 2-6MHz, so that the detection personnel can locate and evaluate the defects more accurately, and at the same time improve the detection sensitivity;

[0015] In the utility model, the bottom of the piezoelectric chip is densely covered with tiny pits, which can serve as small reflectors of sound waves, helping the sound waves to form a more uniform sound field distribution inside the object being inspected, which can improve the positioning accuracy and resolution of defects;

[0016] In the utility model, the tiny pits are arranged in a regular hexagon. Since the hexagon has the best filling efficiency, the space can be fully utilized, thereby increasing the number of contact points between the sound wave and the surface of the detected object. The shape and size of each hexagonal pit are the same, so that the interference and scattering effects on the sound wave when propagating in the array are more uniform and consistent, thereby improving the coupling efficiency and resolution of the sound wave. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of the utility model;

[0019] Figure 2 for Figure 1Schematic diagram of the structure of a medium-voltage chip viewed from above.

[0020] In the figure: 1. Delay block; 2. Sound insulation layer; 3. Probe core; 4. Sound absorbing material; 5. Shell; 6. Piezoelectric chip; 7. Tiny pits. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] Example: Reference Figure 1 A square small-section longitudinal wave dual crystal probe for ultrasonic detection of the arc part of a machine base shown in the figure comprises a delay block 1, a sound insulation layer 2, a probe core 3, a sound absorbing material 4 and a piezoelectric chip 6 installed in a shell 5. The probe core 3 is provided in two groups and is symmetrically arranged on the left and right. The two probe cores 3 are arranged in an eight-shaped shape. The two probe cores 3 are arranged in the installation groove of the sound absorbing material 4. The sound insulation layer 2 separates the two probe cores 3. There are two groups of piezoelectric chips 6, and each group of piezoelectric chips 6 is adapted to the corresponding longitudinal wave probe core 3. The two piezoelectric chips 6 are both set to a square shape. The sizes of the two piezoelectric chips 6 are both set to 4mm×2mm, and the total size is 4mm×4mm. When working, the working frequency of the longitudinal wave dual crystal probe is set to 4MHz.

[0023] The piezoelectric chip 6 is set to be square. According to the distribution characteristics of the ultrasonic field, when the diameter size of the circular piezoelectric chip and the side length size of the square piezoelectric chip are the same, the sound field directivity of the square piezoelectric chip is better than that of the circular piezoelectric chip, and the detection sensitivity is high. The size of the two piezoelectric chips 6 is set to 4mm×2mm. The use of a piezoelectric chip 6 with a small cross-section can solve the problem of poor surface coupling between the probe and the transition arc part of the machine base. At the same time, the frequency is controlled to be 2-6MHz (too high frequency will cause the wavelength to be too short, and some defects or structures cannot be fully distinguished, affecting the detection accuracy). The higher the frequency, the shorter the wavelength of the ultrasonic wave, which means that the ultrasonic wave propagating in the material can more accurately reflect the size and position of the defect. The frequency of 2-6MHz can provide a higher detection resolution, allowing the inspector to locate and evaluate the defect more accurately, while also avoiding the short wavelength affecting the detection accuracy. When propagating in the material, the ultrasonic signal will attenuate with the increase of the propagation distance. Since the wavelength of the 2-6MHz ultrasonic wave is short, its attenuation rate is relatively slow, so it can maintain a high signal strength at a long distance, thereby improving the detection sensitivity.

[0024] It should be noted that the longitudinal wave dual crystal probe has a concentrated area of ​​sound energy. This feature can be used to improve the detection sensitivity of the probe.

[0025] As a preferred implementation in this embodiment, the operating frequency of the longitudinal wave dual crystal probe is set to 4 MHz. At this frequency, the longitudinal wave dual crystal probe has very high resolution and detection sensitivity when detecting the arc part of the machine base.

[0026] As a preferred implementation in this embodiment, Figure 1 As shown in the figure, the focal length of the longitudinal wave dual crystal probe is set to 12-19mm (too large or too small focal length will reduce the detection resolution and sensitivity), that is, the vertical distance from the focal position F to the center position of the piezoelectric chip 6. The focal length of 12-19mm can make the longitudinal wave dual crystal probe produce a more focused ultrasonic sound beam, and the sound energy is more concentrated at the defect, thereby improving the sensitivity and resolution of detection. At the same time, the focused sound beam can reduce the diffusion of ultrasonic waves during propagation, thereby reducing the attenuation and scattering of the signal before reaching the expected detection area, which helps to reduce interference signals from non-target areas and improve the accuracy of detection.

[0027] As a preferred implementation method in this embodiment, the focal length of the longitudinal wave dual crystal probe is set to 15 mm. When the focal length is 15 mm, the acoustic energy is most concentrated at the defect, further improving the sensitivity and resolution of the detection, while also further improving the accuracy of the detection.

[0028] As a preferred implementation in this embodiment, Figure 2 As shown, the bottom of the piezoelectric chip 6 is densely covered with tiny pits 7, which can serve as small reflectors of sound waves, helping the sound waves to form a more uniform sound field distribution inside the object being inspected, which can improve the positioning accuracy and resolution of defects.

[0029] As a preferred implementation in this embodiment, Figure 2 As shown, the tiny pits 7 are arranged in a regular hexagon. Since the hexagon has the best filling efficiency and can make full use of the space, the hexagonal pit array can provide more pits than other shaped pit arrays in the same area, thereby increasing the number of contact points between the sound wave and the surface of the object being detected. The shape and size of each hexagonal pit are the same, so that the interference and scattering effects of the sound wave when propagating in the array are more uniform and consistent, thereby improving the coupling efficiency and resolution of the sound wave.

[0030] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A square small-section longitudinal wave dual crystal probe for ultrasonic detection of arc parts of a machine base, comprising a delay block (1), a sound insulation layer (2), a probe core (3), a sound absorbing material (4) and a piezoelectric chip (6) installed in a shell (5), wherein the probe core (3) is provided in two groups and is arranged symmetrically on the left and right, the two probe cores (3) are arranged in an eight-shaped shape, the two probe cores (3) are arranged in the installation groove of the sound absorbing material (4), the sound insulation layer (2) separates the two probe cores (3), the piezoelectric chip (6) is provided in two groups, and each group of the piezoelectric chip (6) is adapted to the corresponding longitudinal wave probe core (3), characterized in that: The two piezoelectric chips (6) are both set to be square, and the sizes of the two piezoelectric chips (6) are both set to be 4 mm×2 mm, with a total size of 4 mm×4 mm. When working, the working frequency of the longitudinal wave dual crystal probe is set to 2-6 MHz.

2. A square small cross-section longitudinal wave dual crystal probe for ultrasonic detection of arc parts of a machine base according to claim 1, characterized in that: The operating frequency of the longitudinal wave dual crystal probe is set to 4 MHz.

3. A square small cross-section longitudinal wave dual crystal probe for ultrasonic detection of arc parts of a machine base according to claim 1, characterized in that: The focal length of the longitudinal wave dual crystal probe is set to 12-19 mm.

4. A square small cross-section longitudinal wave dual crystal probe for ultrasonic detection of arc parts of a machine base according to claim 3, characterized in that: The focal length of the longitudinal wave dual crystal probe is set to 15 mm.

5. The square small cross-section longitudinal wave dual crystal probe for ultrasonic detection of arc parts of machine base according to claim 1, characterized in that: The bottom of the piezoelectric chip (6) is densely covered with tiny pits (7).

6. A square small cross-section longitudinal wave dual crystal probe for ultrasonic detection of arc parts of a machine base according to claim 5, characterized in that: The micro-pits (7) are arranged in a regular hexagonal shape.

Images