CN109239201B

CN109239201B - Portable automatic clamping device for nonlinear ultrasonic detection

Info

Publication number: CN109239201B
Application number: CN201811024398.7A
Authority: CN
Inventors: 胡宏伟; 何绪晖; 易可夫; 徐晓强; 王向红; 曾慧婕; 刘文杰
Original assignee: Changsha University of Science and Technology
Current assignee: Changsha University of Science and Technology
Priority date: 2018-09-04
Filing date: 2018-09-04
Publication date: 2021-04-02
Anticipated expiration: 2038-09-04
Also published as: CN109239201A

Abstract

The invention discloses a portable automatic clamping device for nonlinear ultrasonic detection, comprising: a mechanical claw assembly, a display screen, a controller, a small stepping motor, an electromagnet, a pressure sensor, a square connecting rod, a wedge, an ultrasonic excitation Transducer, ultrasonic receiving transducer. The wedge block and electromagnet equipped with ultrasonic excitation transducer and ultrasonic receiving transducer are installed on the square connecting rod; the small stepping motor is controlled by the controller to drive the mechanical claw assembly to clamp the workpiece to be tested; the electromagnet is energized The wedge block equipped with the ultrasonic excitation transducer and the ultrasonic receiving transducer is adsorbed on the surface of the metal component; the coupling pressure control of nonlinear ultrasonic detection is realized through pressure sensor measurement and stepper motor feedback control, which reduces the need for transducer installation. The effect of poor clipping on the results of nonlinear ultrasonic testing. The invention can be used for the detection of plane and curved components, and has the advantages of automatic clamping, strong applicability, convenient installation and use, and the like.

Description

Portable automatic clamping device for nonlinear ultrasonic detection

Technical Field

The invention relates to the field of nondestructive testing, in particular to a portable automatic clamping device for nonlinear ultrasonic testing, which can be used for automatically clamping a transducer during nonlinear ultrasonic testing of curved and planar metal members.

Background

The curved metal components are widely applied to key equipment in the industries of aerospace, nuclear power, ships, pressure vessels and the like, are influenced by various factors such as manufacturing process, external environment, working load and the like during working, and have various common defects such as corrosion, fatigue, cracks, looseness and the like.

Ultrasonic detection is one of the most common nondestructive detection methods, but is limited by factors such as wavelength, and the traditional linear ultrasonic nondestructive detection method is not sensitive to early-stage micro damage of a component, such as microcrack, mechanical property degradation, fatigue damage and the like, and is difficult to effectively detect. The nonlinear ultrasonic detection utilizes the principles of higher harmonic, subharmonic, beam aliasing and the like generated when ultrasonic waves pass through micro-damage, overcomes the defect of micro-damage of the traditional linear ultrasonic detection, and has wide application prospect.

However, in the actual non-linear ultrasonic nondestructive testing, in order to avoid the non-linear influence of the testing system, the requirements on the stability of the transducer clamping and coupling are very strict, the existing simple manual clamp is labor-consuming to install, complicated in steps and insufficient in universality, so that the field non-linear ultrasonic testing is very difficult, and the reliability of the measuring result is poor. Especially for curved surface members, the difficulty of clamping the transducer is higher, the measurement efficiency is greatly influenced, and accurate and stable measurement results are difficult to obtain.

In order to improve the accuracy of the nonlinear ultrasonic detection result and the usability in the implementation process, the design of the portable automatic clamping device for the ultrasonic nonlinear nondestructive detection has important significance for practical engineering application. In the field of non-linear ultrasonic nondestructive testing research, a non-linear ultrasonic testing method and data analysis are mainly used, and a related automatic clamping device is lacked.

For example, in an invention patent with an issued publication number of CN101806778B and an issued publication date of 2011, 7, and 27, a continuous online detection method for nonlinear ultrasonic nondestructive testing during early fatigue damage of metal is invented, but the patent only provides a theoretical method for nonlinear ultrasonic nondestructive testing, and does not describe in detail a probe clamping device during nonlinear ultrasonic testing. In addition, the invention patent with the publication number of CN205581057U and the publication date of 2016, 9 and 14 provides an oblique incidence nonlinear ultrasonic nondestructive testing device, but the device can only be used for nonlinear ultrasonic testing of a plane workpiece, and can only be used for fixed position testing, so that the portability is poor.

Disclosure of Invention

The invention aims to provide a portable automatic clamping device for nonlinear ultrasonic detection, which can realize stable clamping of an ultrasonic transducer, ensure good coupling of the transducer and a workpiece, and can be used for automation of a clamping process of nonlinear ultrasonic detection of a curved surface member. The mechanical claw assembly and the electromagnet are driven by the controller to enable the wedge block provided with the probe to be adsorbed on the surface of the measured metal component, so that clamping automation is realized. Coupling pressure control is realized through the pressure sensor, and stable coupling of the transducer and the workpiece is guaranteed. The device can be used for detecting the metal curved surface component and improves the adaptability to the detected metal component.

The technical scheme of the invention is as follows: a portable automatic clamping device for nonlinear ultrasonic detection comprises: mechanical claw subassembly, display screen, controller, small-size step motor, electro-magnet, pressure sensor, square connecting rod, voussoir, supersound excitation transducer, supersound receiving transducer are equipped with the portable handle in the middle of the device roof for it is portable to install, mechanical claw subassembly includes: the clamping plate, the clamping jaw plate, the U-shaped threaded connecting piece, the openable ring buckle, the short cylindrical connecting rod and the sleeve. The two clamping plates are connected side by a short cylindrical connecting rod, and the two clamping plates at opposite angles are fixedly connected with a small-sized stepping motor by screws and bolts. Two small stepping motors are adopted, so that the weight of the device is reduced, the portability of the device is improved, and the small stepping motors are more accurate and stable. The small-sized stepping motor is connected with the two clamping jaw plates through a U-shaped threaded connecting piece, the two clamping jaw plates are connected with the two clamping plates through double-headed screws, and a sleeve is sleeved between the two clamping jaw plates. When the small-sized stepping motor rotates, the clamping jaw plate can be clamped on the surface of a workpiece to be measured around the central axial direction of the double-headed screw through the thread rotation of the U-shaped threaded connecting piece, and the mechanical jaws on the same side of the small-sized stepping motor are connected through the long cylindrical connecting rod, so that the small-sized stepping motor can drive the mechanical jaw assembly on the same side at the same time. The clamping jaw plate end of the mechanical jaw assembly is provided with a ring buckle capable of being opened and closed, the ring buckle is used for being installed on a round shaft at two ends of a square connecting rod and is fixed by a screw, and a gasket is arranged, so that the square connecting rod is installed more stably. The effect of ring buckle lies in making square connecting rod can the axial rotation for the shape, the size of work piece are laminated better to electro-magnet, the voussoir bottom surface on the square connecting rod.

Two electromagnets are arranged at two ends of the square connecting rod, three ultrasonic excitation transducers or ultrasonic receiving transducers are arranged between the electromagnets, the ultrasonic excitation transducers or the ultrasonic receiving transducers are arranged on the wedge block through screws, the stability of the ultrasonic excitation transducers and the ultrasonic receiving transducers in the measuring process is ensured, and different measuring modes such as single-probe transceiving, multi-probe transceiving and the like can be realized according to the condition of a workpiece to be measured.

The thickness of the electromagnet is the same as that of the wedge block, and the bottom of the electromagnet is provided with a pressure sensor for observing the pressure value between the bottom surface of the wedge block and the measuring workpiece.

Before the measurement is started, an electromagnet is arranged at a corresponding position, and an ultrasonic excitation transducer and an ultrasonic receiving transducer are arranged on a wedge block; and the required pressure value N for measurement is set by the controller.

When the measured workpiece is observed to be close to the bottom of the wedge block, the small stepping motor is suspended to be driven to rotate, and the square connecting rod is manually rotated and adjusted, so that the bottom surface of the wedge block is parallel to the surface of the measured workpiece as much as possible; after the adjustment is finished, driving the mechanical claw assembly until the bottoms of the electromagnet and the wedge block are attached to the surface of the workpiece to be measured; when the controller obtains pressure feedback of a pressure sensor at the bottom of the electromagnet, the controller suspends driving the small stepping motor and energizes the electromagnet, so that the electromagnet and the wedge block are adsorbed to the surface of the workpiece to be detected; and then the controller controls the small stepping motor to drive the mechanical claw assembly to clamp the surface of the workpiece to be detected.

The display screen shows pressure sensor's pressure value, if the pressure value N that shows is less than the required pressure value N of set for measurement, then start the small-size step motor of controller control, drive gripper subassembly continues to press from both sides tightly to the measured workpiece surface, and the required pressure value of just stopping driving gripper subassembly is measured to pressure value more than or equal to the set for setting for the pressure value.

The ultrasonic testing device has the advantages of being capable of being used for nonlinear ultrasonic testing of curved and planar members, and having the advantages of automatic clamping, strong applicability, convenience in mounting and use and the like.

Drawings

FIG. 1 is a schematic view of the overall assembly of the apparatus of the present invention

FIG. 2 is a schematic view of a mechanical gripper assembly of the present invention

FIG. 3 is a schematic view of the connection between the gripper plate and the small stepping motor of the device of the present invention

FIG. 4 is a schematic view of a square connecting rod of the device of the present invention

FIG. 5 is a schematic view of the operation of the apparatus of the present invention

Detailed Description

The invention will be further explained with reference to the drawings.

As shown in fig. 1, a portable automatic clamping device for nonlinear ultrasonic testing comprises: mechanical claw subassembly, display screen, controller, small-size step motor, electro-magnet, pressure sensor, square connecting rod, voussoir, supersound excitation transducer, supersound receiving transducer are equipped with in the middle of the device roof and are carried the handle for the device is portable, and it is shown in combination figure 2, mechanical claw subassembly includes: the clamping plate, the clamping jaw plate, the U-shaped threaded connecting piece, the openable ring buckle, the short cylindrical connecting rod and the sleeve. The two clamping plates 9 are connected side by two short cylindrical connecting rods 11, the two clamping jaw plates 10 are connected with the two clamping plates 9 by double-headed screws, and a sleeve 12 is arranged between the two clamping jaw plates 10. The mechanical claw components 4 on the same side are respectively connected by long cylindrical connecting rods 3.

As shown in fig. 3, the small stepping motor 2 is fixedly connected between the two clamping plates 9 by screws or bolts, and the small stepping motor 2 is connected with the two jaw plates 10 by a U-shaped threaded connector 14.

As shown in fig. 4, an openable and closable ring buckle 13 is designed at an end of the clamping jaw plate 10 of the mechanical jaw assembly 4 shown in fig. 3, and is installed at a corresponding position of the square connecting rod 6 and fixedly connected by a screw bolt. The ends of the two square connecting rods 6 are provided with electromagnets 15 through screws, and the bottoms of the electromagnets 15 are provided with pressure sensors 16; a wedge 17 is mounted between the two electromagnets 15 with screws, and an ultrasonic excitation transducer 5 or an ultrasonic receiving transducer 8 is mounted on the wedge 17 by screw threads.

Before the measurement is started, according to the positions, the electromagnet 15 and the wedge 17 are installed on each square connecting rod 6 through screws, and each square connecting rod 6 is installed in the corresponding circular buckle 13 of the clamping jaw plate 10; the pressure value (N) required for the measurement is set by the controller 7 to: 50.

the device driving control process: after a power switch is started, the controller 7 simultaneously controls the small stepping motors 2 on two sides, the small stepping motors 2 can be clamped around the central axial direction of a stud bolt by a screw thread driving clamping jaw plate 10 of a U-shaped threaded connection 14 piece, when the bottom of a wedge block 17 and the bottom of an electromagnet 15 are close to a workpiece to be measured, the small stepping motors 2 are suspended to be driven to rotate, a square connecting rod 6 is manually rotated and adjusted, and the bottom of the wedge block 17 is parallel to the surface of the workpiece to be measured as much as possible; after the adjustment is finished, the controller 7 starts the small stepping motor 2 again, and drives the mechanical claw assembly 4 to enable the bottom of the wedge block 17 and the bottom of the electromagnet 15 to be attached to the surface of the workpiece to be measured; when the controller 7 obtains the pressure feedback of the pressure sensor 16 at the bottom of the electromagnet 15, which indicates that the bottom of the wedge 17 and the bottom of the electromagnet 15 have contacted the surface of the workpiece to be tested, the controller 7 stops driving the small-sized stepping motor 2 and energizes the electromagnet 15, so that the electromagnet 15 and the wedge 17 are attracted to the surface of the workpiece to be tested.

The pressure adjusting process of the device comprises the following steps: when the electromagnet 15 and the wedge 17 are adsorbed to the surface of the workpiece to be detected, the display screen 1 displays pressure values as follows: n; if the controller 7 recognizes a pressure value n < the set measured pressure value: and 50, starting the controller 7 to control the small-sized stepping motor 2, driving the clamping jaw plate 10 to clamp the surface of the workpiece to be measured so as to increase the pressure between the bottom of the wedge block 17 and the surface of the workpiece to be measured until the controller 7 recognizes that the pressure value N is more than or equal to the set required pressure value (N): after 50, the gripper assembly 4 is stopped.

The device measurement process comprises the following steps: the transducers required for measurement are the middle ultrasonic excitation transducer 5 and the other three ultrasonic receiving transducers 8 in the three ultrasonic excitation transducers 5; after the required pressure value is reached, the middle ultrasonic excitation transducer 5 is excited, and the measurement information is received by the three ultrasonic receiving transducers 8 and is transmitted to the computer. In the measuring process, different measuring modes such as single-probe transmitting and receiving, multi-probe transmitting and receiving and the like can be realized according to the condition of the workpiece to be measured. The above process is merely illustrative, and the measurement is not exclusive.

Claims

1. A portable automatic clamping device for nonlinear ultrasonic testing, comprising a mechanical claw assembly (4), a long cylindrical connecting rod (3), a display screen (1), a controller (7), a small stepping motor ( 2), electromagnet (15), pressure sensor (16), square connecting rod (6), wedge (17), ultrasonic excitation transducer (5), ultrasonic receiving transducer (8);

The mechanical claw assembly (4) includes a clamping plate (9), a clamping claw plate (10), a U-shaped threaded connecting piece (14), a stretchable ring buckle (13), a short cylindrical connecting rod (11), a sleeve Cylinder (12); two splints (9) are connected side by side by two short cylindrical connecting rods (11), two clamping jaw plates (10) and two splints (9) are connected by double-headed screws, and are connected between the two A sleeve (12) is installed between the clamping jaw plates (10); the two sets of mechanical jaw assemblies (4) are respectively connected by long cylindrical connecting rods (3); the two clamping plates (9) are fixedly connected by screws and bolts A small stepping motor (2), the small stepping motor (2) and the two jaw plates (10) are connected by a U-shaped threaded connector (14); Ring buckles (13) are installed on the circular shaft positions at both ends of the square connecting rod (6), and are fixedly connected by screws and bolts; the two ends of each square connecting rod (6) are respectively equipped with electromagnets (15) through screws. , and a pressure sensor (16) is installed at the bottom of the electromagnets (15) at both ends; a wedge (17) is installed between the two electromagnets (15) with screws, and three an ultrasonic excitation transducer (5) or an ultrasonic receiving transducer (8).

2. A portable automatic clamping device for nonlinear ultrasonic detection according to claim 1, characterized in that, when the small stepping motor (2) rotates, the thread of the U-shaped threaded connector (14) passes through the Rotate so that the gripper plate (10) can be clamped around the central axis of the double-headed screw on the surface of the workpiece to be tested, and is connected with the mechanical gripper assembly (4) on the same side of the small stepping motor (2) by a long cylindrical connecting rod (3). The purpose is that the small stepping motor (2) drives the mechanical claw assembly (4) on the same side at the same time, and the stretchable ring buckle (13) at the end of the gripper plate (10) is used to install on the two sides of the square connecting rod (6). The purpose is to make the square connecting rod (6) rotate and adjust, and electromagnets (15) are installed at both ends, so that the wedges (17) can be adsorbed on the surface of the workpiece to be tested, and the electromagnets (15) ) is equipped with a pressure sensor at the bottom, the pressure value required for detection is set by the controller (7), and the pressure value of the pressure sensor (16) is displayed on the display screen (1), if the pressure value is less than the pressure value required for the set detection, the The controller (7) controls the small stepping motor (2), and drives the mechanical claw assembly (4) to continue clamping to the surface of the workpiece to be tested, until the controller (7) recognizes that the pressure value is greater than or equal to the pressure value required for the set detection , the detection can be started.

3. A portable automatic clamping device for nonlinear ultrasonic detection according to claim 1, wherein the ultrasonic excitation transducer (5) or the ultrasonic receiving transducer on the three wedges (17) (8), according to the condition of the workpiece to be tested, different measurement methods of single-probe sending and receiving and multi-probe sending and receiving can be realized.