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CN-121978221-A - Electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly

CN121978221ACN 121978221 ACN121978221 ACN 121978221ACN-121978221-A

Abstract

The invention provides an electromagnetic ultrasonic transducer probe of a HalbacH permanent magnet assembly, which comprises a shell, a magnet assembly, a coil assembly and a driving mechanism, wherein the magnet assembly is accommodated in the shell and is formed by arranging a plurality of magnets according to preset polarities, the coil assembly is arranged outside the shell and is positioned at one side close to a test piece and used for exciting ultrasonic waves in the bias magnetic field and receiving ultrasonic signals reflected from the test piece after pulse current is introduced, a fixing frame is arranged at the periphery of the magnet assembly and used for installing and fixing the magnet assembly, a movable interval is arranged between the fixing frame and the inner wall of the shell and is positioned at one side of the magnet assembly, which is away from the test piece, and the driving mechanism is installed on the shell and connected with the fixing frame and used for driving the magnet assembly to be far away from or close to the coil assembly along the direction perpendicular to the test piece so that the distance between the magnet assembly and the coil assembly is different. The bias magnetic field strength acting on the test piece is adjusted by adjusting the position of the magnetic assembly.

Inventors

  • ZHOU BAOPING
  • MA CHUNCHENG

Assignees

  • 包头市英思特稀磁新材料股份有限公司

Dates

Publication Date
20260505
Application Date
20251217

Claims (9)

  1. 1. An electromagnetic ultrasonic transducer probe of HalbacH permanent magnet components is characterized by comprising a shell (1), a magnet group (2), a coil component (3) and a driving mechanism (4); The magnet group (2) is accommodated in the shell (1) and is formed by arranging a plurality of magnets according to preset polarities, and is used for providing a bias magnetic field, the coil assembly (3) is arranged outside the shell (1) and is positioned at one side close to the test piece, and is used for exciting ultrasonic waves in the bias magnetic field and receiving ultrasonic wave signals reflected from the test piece after pulse current is introduced; The periphery of the magnet group (2) is provided with a fixing frame (5), the fixing frame (5) is used for installing and fixing the magnet group (2), a movable interval is arranged between the fixing frame (5) and the inner wall of the shell (1), the movable interval is positioned on one side of the magnet group (2) away from the test piece, and the driving mechanism (4) is installed on the shell and connected with the fixing frame (5) and used for driving the magnet group (2) to be far away from or close to the coil assembly (3) along the direction perpendicular to the test piece, so that the distances between the magnet group (2) and the coil assembly (3) are different.
  2. 2. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 1, wherein the magnet group (2) includes a first magnet group (21) and a second magnet group (22), the first magnet group (21) and the second magnet group (22) are arranged adjacently up and down, the first magnet group (21) is composed of a plurality of first magnets (210), the second magnet group (22) is composed of a plurality of second magnets (220), the number and positions of the first magnets (210) are in one-to-one correspondence with those of the second magnets, and the magnetizing directions are consistent.
  3. 3. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 2, wherein the first magnet (210) has a square structure, the second magnet (220) has a trapezoid structure, the first magnet (210) is positioned on the top side of the second magnet (220), the second magnet (220) is expanded from the bottom end of the first magnet (210) to a trapezoid structure or contracted from the bottom end of the first magnet (210) to a trapezoid structure, and adjacent magnets are attached to each other.
  4. 4. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assemblies according to claim 2, wherein the number of the first magnets (210) is 5, the magnetizing directions of the 5 first magnets (210) are sequentially from left to right, and are vertically downward, horizontally leftward, vertically upward, horizontally rightward, and vertically downward, the number of the second magnets (220) is 5, and the magnetizing directions of the 5 second magnets (220) are sequentially from left to right, and are vertically downward, horizontally leftward, vertically upward, horizontally rightward, and vertically downward.
  5. 5. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 2, wherein said plurality of first magnets (210) are arranged in a large-small staggered configuration and said plurality of second magnets (220) are arranged in a large-small staggered configuration in a manner consistent with said first magnets (210).
  6. 6. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 1, wherein the driving mechanism (4) is a screw-nut mechanism and comprises a screw (41), a threaded hole (11) which is in threaded connection with the screw (41) is longitudinally penetrated on the shell (1), one end of the screw (41) is in rotary connection with the fixing frame (5) through a bearing, and the other end of the screw (41) passes through the threaded hole (11) upwards and extends out of the shell (1).
  7. 7. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 1, wherein the coil assembly (3) comprises an excitation coil (6), a first base plate (7), a receiving coil (8) and a second base plate (9), the excitation coil (6), the first base plate (7), the receiving coil (8) and the second base plate (9) are sequentially arranged from top to bottom, a third base plate (10) is arranged on the bottom side of the shell (1), the excitation coil (6) is arranged below the third base plate (10) and is positioned between the third base plate (10) and the first base plate (7), two ends of the first base plate (7), the second base plate (9) and the third base plate (10) extend out of the excitation coil (6) and the receiving coil (8) respectively, the first base plate (7) and the second base plate (9) are made of insulating materials, and the third base plate (10) and the shell (1) are made of non-magnetic materials through bolt fixing connection.
  8. 8. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 1, wherein the excitation coil (6) has a planar racetrack coil structure and the receiving coil (8) has a planar racetrack coil structure.
  9. 9. The electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly according to claim 1, further comprising a lift-off sensor (12), the lift-off sensor (12) being configured to detect a lift-off distance between the probe and a surface of the test piece, the driving mechanism (4) being configured to drive the displacement of the magnet assembly (2) in accordance with a detection signal of the lift-off sensor (12). A method of lifting an electromagnetic ultrasonic transducer probe employing the HalbacH permanent magnet assembly of claim 1, comprising the steps of; s1, acquiring the current lifting distance between a probe and a test piece; s2, judging whether the current lifting distance exceeds a preset lifting range or not; and S3, when the distance exceeds the preset distance, determining the target position of the magnet group (2) corresponding to the current distance, and driving the magnet group (2) to move to the target position according to the corresponding relation between the preset distance and the position of the magnet group (2), wherein the corresponding relation is configured to enable the bias magnetic field intensity acting on the surface of the test piece to be kept stable by adjusting the magnet group (2) to the corresponding target position under different distances.

Description

Electromagnetic ultrasonic transducer probe of HalbacH permanent magnet assembly Technical Field The invention relates to the technical field of electromagnetic ultrasonic transducers, in particular to an electromagnetic ultrasonic transducer probe of a HalbacH permanent magnet assembly. Background The electromagnetic ultrasonic detection technology is a non-contact nondestructive detection method without a coupling agent, and is widely applied to industrial online detection. The technology provides a bias magnetic field through the permanent magnet in the probe, and the coil excites ultrasonic waves, so that the technology has the advantages of flexible wave mode, no need of test piece surface treatment and the like, and the detection process usually does not need to pretreat the test piece surface, such as polishing and coating couplant, thereby not only improving the detection efficiency, but also avoiding the damage to the test piece surface possibly caused by contact detection. However, the permanent magnet set of the existing probe is generally fixedly installed, and in practical application, particularly when aiming at a test piece with uneven surface, the lifting distance is changed due to errors such as surface fluctuation and vibration of the test piece, so that the attenuation of the effective bias magnetic field intensity is directly caused, and further the attenuation of an excited ultrasonic signal is caused, and the stability, reliability and precision of detection are affected. Disclosure of Invention The invention aims to provide an electromagnetic ultrasonic transducer probe of a HalbacH permanent magnet assembly, which solves the technical problem of providing an electromagnetic ultrasonic transducer probe capable of adjusting the distance between a magnet group and an excitation coil. In order to achieve the aim, the invention adopts the technical scheme that the electromagnetic ultrasonic transducer probe of the HalbacH permanent magnet assembly comprises a shell, a magnet group, a coil assembly and a driving mechanism; The magnet group is accommodated in the shell and is formed by arranging a plurality of magnets according to preset polarities, and is used for providing a bias magnetic field, the coil assembly is arranged outside the shell and is positioned at one side close to the test piece and is used for exciting ultrasonic waves in the bias magnetic field and receiving ultrasonic wave signals reflected from the test piece after pulse current is introduced; The periphery of the magnet group is provided with a fixing frame, the fixing frame is used for installing and fixing the magnet group, a movable interval is arranged between the fixing frame and the inner wall of the shell, the movable interval is positioned on one side of the magnet group, which is away from the test piece, and the driving mechanism is installed on the shell and connected with the fixing frame and used for driving the magnet group to be far away from or close to the coil assembly along the direction perpendicular to the test piece, so that the distance between the magnet group and the coil assembly is different. Further, the magnet group comprises a first magnet group and a second magnet group, the first magnet group and the second magnet group are arranged up and down adjacently, the first magnet group is composed of a plurality of first magnets, the second magnet group is composed of a plurality of second magnets, the number and the positions of the first magnets are in one-to-one correspondence with the number and the positions of the second magnets, and magnetizing directions are consistent. Further, the first magnet is of a square structure, the second magnet is of a trapezoid structure, the first magnet is located on the top side of the second magnet, the second magnet is expanded into the trapezoid structure from the bottom end of the first magnet, or the bottom end of the first magnet is contracted into the trapezoid structure, and adjacent magnets are attached to each other. Further, the number of the first magnets is 5, the magnetizing directions of the 5 first magnets are from left to right in sequence, namely, vertically downward, horizontally leftward, vertically upward, horizontally rightward and vertically downward, the number of the second magnets is 5, and the magnetizing directions of the 5 second magnets are from left to right in sequence, namely, vertically downward, horizontally leftward, vertically upward, horizontally rightward and vertically downward. Furthermore, the first magnets are arranged in a large-small staggered manner, and the second magnets are arranged in a large-small staggered manner in a manner consistent with the first magnets. Further, the driving mechanism is a screw-nut mechanism and comprises a screw rod, a threaded hole in threaded connection with the screw rod is longitudinally formed in the shell, one end of the screw rod is rotationally connected with the fixing