Phased array self-focusing transducer

Abstract

The application discloses a phased array self-focusing transducer, which comprises a transducer shell, a transducer wiring end, a cable, a piezoelectric wafer, an acoustic lens, a wedge, a transducer wiring core and a detachable screw; different incident angle ultrasonic waves are excited by using phased array ultrasonic electronic scanning, and after physical focusing of the acoustic lens and the curved lens, scanning of different focusing depth ranges is formed in the workpiece. The application changes the transducer structure by design, realizes the purpose of single scanning of different depth ranges, and improves the detection efficiency and the defect detection rate.

Description

TECHNICAL FIELD

[0001] The present application relates to a transducer, in particular to a phased array self-focusing transducer. BACKGROUND

[0002] Phased array ultrasonic detection is an ultrasonic detection method that according to a set delay rule excites each piezoelectric wafer (vibration element) of a phased array array probe to synthesize a sound beam to realize the functions of sound beam movement, deflection and focusing, and then processes the received ultrasonic signals according to a certain delay rule and displays the internal state of the detected object in the form of an image. Compared with the traditional A-type pulse reflection method ultrasonic detection, the phased array ultrasonic transducer is made of a multi-wafer composite material, and each wafer can be used as an independent excitation ultrasonic wave, and finally converges into a sound wave with a certain wave front according to the Huygens principle. Therefore, the phased array ultrasonic transducer has the characteristics that one vibration element corresponds to one channel, and the synthesized sound beam is flexible and controllable.

[0003] In addition, the phased array ultrasonic composite piezoelectric wafer has a certain flexibility compared with the traditional piezoelectric wafer. Thanks to this advantage, the composite piezoelectric wafer can be bent into a certain degree of curved surface to achieve a certain fixed physical focusing. At present, most of the small diameter pipe detection transducers sold on the market use the self-focusing characteristics of piezoelectric wafers to further reduce the sound field focal length and achieve the purpose of thin-walled small diameter detection.

[0004] However, the self-focusing composite piezoelectric wafer sound field focal point is often a fixed focal point at a certain position realized under the joint action of physical focusing and electronic focusing. If you want to change the focal point position, you usually need to change the focusing rule to achieve it by changing the electronic focusing. It cannot achieve the purpose of focusing at different depth ranges in a single scan. SUMMARY

[0005] The present application provides a phased array self-focusing transducer, which realizes the purpose of phased array ultrasonic single detection multi-point focusing, and improves the defect detection rate and detection efficiency.

[0006] The present application is implemented by adopting the following technical solutions:

[0007] A phased array self-focusing transducer, comprising a fixedly connected transducer shell and a wedge block; a piezoelectric wafer is arranged in the transducer shell, and an acoustic lens is arranged in the wedge block, and the acoustic impedance of the wedge block is smaller than that of the acoustic lens; the piezoelectric wafer comprises a plurality of wafers parallel to each other, one side of the wafer is in contact with the acoustic lens, and the other side is connected to a transducer wiring core through different cable wires respectively.

[0008] Further, each wafer is connected to a cable wire singly and independently.

[0009] Further, the transducer wiring core is formed by converging and winding all the cable wires.

[0010] Further, the piezoelectric wafer is filled with damping blocks between the piezoelectric wafer and the transducer shell.

[0011] Further, the cable is arranged in the transducer shell, the acoustic lens and the wedge are fixedly connected, and the transducer shell and the wedge are connected through a plurality of detachable screws.

[0012] Further, the acoustic lens is embedded in the wedge, and there is no gap between the acoustic lens and the wedge.

[0013] Further, the piezoelectric wafer is embedded in the transducer shell.

[0014] Further, the wedge is a curved wedge with non-single curvature.

[0015] Further, the acoustic lens is a cylindrical lens or a spherical lens.

[0016] Further, the transducer wiring core is arranged in the transducer wiring end, and the transducer wiring end is fixed outside the transducer shell.

[0017] The present application has at least the following beneficial technical effects:

[0018] The phased array self-focusing transducer provided by the present application comprises a wedge, the wedge is provided with an acoustic lens, the acoustic impedance of the wedge is smaller than that of the acoustic lens, a transducer structure for realizing phased array ultrasonic self-focusing is provided, and the longitudinal waves generated by the composite piezoelectric wafer can be physically focused twice through the acoustic lens and the wedge, so that the purpose of focusing at different depths in a workpiece is achieved. Specifically, the phased array detector independently allocates control currents to each composite piezoelectric wafer through the transducer wiring core of the transducer wiring end and the cable, the piezoelectric wafer is affected by the damping block and generates a wideband narrow pulse longitudinal wave with a certain delay rule under the action of the inverse piezoelectric effect, the incident longitudinal wave is refracted and focused after passing through the acoustic lens and entering the wedge, and the focal length is related to the curvature radius of the acoustic lens. The ultrasonic wave focused by the acoustic lens is reflected at the curved surface of the wedge with non-single curvature, the path of the incident longitudinal wave is changed, and physical focusing is further generated, and the sound wave is finally refracted through the transducer and the workpiece interface to form a certain fixed focusing depth.

[0019] In addition, by using the characteristics of phased array ultrasonic electronic control fan scanning, the longitudinal waves with different wave front angles are formed by changing the control currents, and after the physical focusing of the acoustic lens and the wedge with non-single curvature, the acoustic field with different focusing depths is formed. Due to the high pulse repetition frequency of phased array ultrasonic fan scanning, electronic scanning in a certain angle range can be realized in a very short time, and by using this characteristic, single scanning in different depth ranges can be realized.

[0020] Further, the piezoelectric wafer is filled with damping blocks between the piezoelectric wafer and the transducer shell, which can effectively increase the excitation pulse bandwidth.BRIEF DESCRIPTION OF DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a perspective view of the transducer;

[0022] Figure 2 is a front view of the transducer;

[0023] Figure 3 is a left view of the transducer;

[0024] Figure 4 is a top view of the transducer.

[0025] BRIEF DESCRIPTION OF REFERENCE NUMERALS:

[0026] 1 represents a transducer housing;

[0027] 2 represents a transducer terminal;

[0028] 3 represents a cable;

[0029] 4 represents a composite piezoelectric wafer;

[0030] 5 represents an acoustic lens;

[0031] 6 represents a wedge;

[0032] 7 represents a transducer terminal core;

[0033] 8 represents a detachable screw;

[0034] 9 represents a focusing mode 1;

[0035] 10 represents a focusing mode 2. DETAILED DESCRIPTION

[0036] In order to make the purpose and technical scheme of the present application more clear and convenient to understand. The present application is further described in detail below in combination with the drawings and examples, the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0037] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more. In the description of the present application, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] It should be understood that the specific embodiments described herein are only used to illustrate and explain the present patent, and are not used to limit the present patent, which is illustrated by the cylindrical acoustic lens and the cylindrical wedge block forming line focusing.

[0039] The application provides a phased array self-focusing transducer, which realizes multiple point focusing in single detection of phased array ultrasonic transducer by changing the structure of the phased array ultrasonic transducer and adopting the characteristics of physical focusing.

[0040] As shown in Figures 1 to 4 A phased array self-focusing transducer, comprising a transducer shell 1, a transducer connecting end 2, a cable 3, a piezoelectric wafer 4, an acoustic lens 5, a wedge block 6, a transducer connecting core 7 and a mounting and dismounting screw 8.

[0041] As shown in Figure 1 The transducer connecting end 2 is fixedly connected to the tail of the transducer shell 1. The transducer connecting end 2 is in a hollow cylindrical structure, and the transducer connecting core 7 is located at the center of the transducer connecting end 2. The transducer connecting core 7 is a bundle of multiple wire rods, and the wire rods are independently insulated and connected with the cable 3.

[0042] As shown in Figure 1As shown, the piezoelectric wafer 4 is a composite piezoelectric wafer, including a plurality of wafer linear array arrangement, embedded in the transducer shell 1, and filled with damping block between the piezoelectric wafer 4 and the transducer shell 1, to increase the excitation pulse bandwidth.

[0043] As shown, Figure 1 The cable 3 and the piezoelectric wafer 4 are fixedly connected by electric welding or the like, and the number of the cable 3 is consistent with the number of the piezoelectric wafer 4, each cable is connected with a wafer independently, and plays a role of independent control. The piezoelectric wafer 4 is in contact with the acoustic lens 5.

[0044] As shown, Figure 1 and Figure 2 The acoustic lens 5 is located inside the wedge 6, and the two are in close contact, and there is no gap on the contact surface. From the tail of the transducer, the acoustic lens 5 is in a "convex" structure. The acoustic lens 5 is a cylindrical lens or a spherical lens. The wedge 6 is a curved wedge, including two mutually perpendicular planes and a curved surface, the curved surface is connected to the two planes at both ends, and the curved surface is a non-single curvature curved surface.

[0045] As shown, Figure 1 The four mounting screws 8 are mounted on the four corners of the transducer shell 1, and the transducer shell 1 and the wedge 6 can be assembled by screwing.

[0046] As shown, Figure 1 The transducer shell 1, the transducer terminal 2, the cable 3, the piezoelectric wafer 4 and the transducer terminal core 7 are a unified whole, and the acoustic lens 5 and the wedge 6 are another whole, and the coupling agent is applied to the surface in contact with the piezoelectric wafer 4 and the acoustic lens 5 during use, and then the four mounting screws are screwed and assembled with the wedge 6.

[0047] As shown, Figure 2 The excitation circuit of the phased array detector transmits the pulse current with time delay sequence to the piezoelectric wafer 4 through the transducer terminal core 7, triggers the piezoelectric wafer 4, and the piezoelectric wafer 4 generates time sequence longitudinal wave ultrasonic pulse under the excitation of the pulse current. The wave front of the time sequence longitudinal wave ultrasonic pulse has a certain angle with the horizontal direction, the ultrasonic pulse is transmitted into the wedge 6 at the acoustic lens 5, and the ultrasonic pulse is physically focused due to the acoustic impedance of the acoustic lens 5 being greater than that of the wedge 6. After the physically focused ultrasonic pulse is reflected through a certain point of the curved surface of the wedge 6, refraction occurs on the wedge and the workpiece surface, and the focusing mode 9 is formed in the workpiece.

[0048] When the excitation circuit of the phased array detector excites the piezoelectric wafer 4 with another pulse current with time delay, due to the different time sequence, the wave front formed by wave superposition will have a certain directivity, and the generated longitudinal wave ultrasonic pulse will be reflected at another point on the surface of the non-single curvature wedge 6 after physical focusing by the acoustic lens 5. The reflected wave is refracted between the wedge and the workpiece surface, forming focusing mode two 10. When using fan scanning of the phased array electronic scanning, the piezoelectric wafer 4 generates longitudinal wave ultrasonic pulses, which are reflected at different positions on the surface of the non-single curvature wedge 6 after physical focusing by the acoustic lens 5. The reflected wave is refracted between the wedge and the workpiece surface, forming different depth ranges of focusing mode, which can achieve the purpose of different depth focusing when performing non-parallel scanning.

Claims

1. A phased array self-focusing transducer, characterized by, The application relates to a transducer with a fixedly connected transducer shell (1) and a wedge block (6); the transducer shell (1) is provided with a piezoelectric wafer (4), the wedge block (6) is provided with an acoustic lens (5), and the acoustic impedance of the wedge block (6) is smaller than that of the acoustic lens (5); the piezoelectric wafer (4) comprises a plurality of wafers in parallel, one side of the wafers is in contact with the acoustic lens (5), and the other side is connected with a transducer wiring core (7) through different cable wires (3) respectively; each wafer is connected with a cable wire (3) singly and independently; the wedge block (6) is a curved surface wedge block with non-single curvature; a damping block is filled between the piezoelectric wafer (4) and the transducer shell (1); the cable wire (3) is arranged in the transducer shell (1), the acoustic lens (5) and the wedge block (6) are fixedly connected, and the transducer shell (1) and the wedge block (6) are connected through a plurality of detachable screws (8); the acoustic lens (5) is embedded in the wedge block (6), and no gap exists between the acoustic lens (5) and the wedge block (6); the piezoelectric wafer (4) is embedded in the transducer shell (1).

2. A phased array self-focusing transducer according to claim 1, wherein, the transducer wiring core (7) is formed by converging and winding all the cable wires (3).

3. A phased array self-focusing transducer according to claim 1, wherein, the acoustic lens (5) is a cylindrical lens or a spherical lens.

4. A phased array self-focusing transducer according to claim 1, wherein, the transducer wiring core (7) is arranged in a transducer wiring end (2), and the transducer wiring end (2) is fixed outside the transducer shell (1). the transducer wiring core (7) is arranged in a transducer wiring end (2), and the transducer wiring end (2) is fixed outside the transducer shell (1).

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