CN113155948A

CN113155948A - Curved surface detection micro-magnetic sensor based on conformal sliding shoes

Info

Publication number: CN113155948A
Application number: CN202110416558.8A
Authority: CN
Inventors: 何存富; 王姗姗; 刘秀成
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2021-07-23

Abstract

The invention discloses a curved surface detection micro-magnetic sensor based on a conformal sliding shoe, wherein the 3D printing sliding shoe is sleeved at the tail end of the micro-magnetic sensor, and the sliding shoe is provided with an end part which is conformally matched with the curved surface of a part to be detected so as to ensure the stable magnetic field coupling between an excitation magnetic circuit of the sensor and the curved surface in the scanning process. The sensor mainly comprises a U-shaped electromagnet, a magnetic field measuring assembly, a packaging shell and a curved conformal sliding shoe. The conformal sliding shoe of curved surface can be changed according to the curved surface of the part to be measured, and the sensor can be used for micro-magnetic signal detection of the crank shaft fillet and the tooth profile surface of the hyperboloid spiral bevel gear.

Description

Curved surface detection micro-magnetic sensor based on conformal sliding shoes

Technical Field

The invention relates to a curved surface detection micro-magnetic sensor, belongs to the technical field of nondestructive detection, and aims to provide a design scheme of a micro-magnetic sensor which can be attached to a complex curved surface in a conformal manner.

Background

The micromagnetic technique has the potential of carrying out nondestructive testing on the surface mechanical properties of parts such as crankshafts, gears and the like, the current research mainly aims at detecting flat plates or test pieces with large curvature radius, the application of the micromagnetic technique in the detection of complex curved surfaces such as crankshaft fillets, hyperboloid spiral bevel gear tooth profile surfaces and the like is very little, and the main reason is that when a conventional sensor is attached to the complex curved surfaces, the stable magnetic field coupling between an excitation magnetic circuit and the curved surfaces is difficult to guarantee. In order to solve the problem, the invention discloses a curved surface detection micro-magnetic sensor based on a conformal sliding shoe, wherein the sliding shoe which is conformally matched with the curved surface of a part to be detected is prepared by utilizing a 3D printing technology and sleeved at the tail end of the micro-magnetic sensor, so that the stable magnetic field coupling between the sensor and the curved surface is realized.

Disclosure of Invention

The invention aims to design a curved surface detection micro-magnetic sensor based on a conformal sliding shoe, wherein the 3D printing sliding shoe is sleeved at the tail end of the micro-magnetic sensor so as to realize that a sensor excitation magnetic circuit and a curved surface have a stable magnetic field during curved surface detection.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a curved surface detects little magnetic sensor based on conformal piston shoes, characterized by at the terminal suit piston shoes of traditional little magnetic detection sensor, the piston shoes have with the conformal tip that matches of part curved surface that awaits measuring, the sensor is when scanning the curved surface, keeps unanimous with the gesture and the lift-off distance of curved surface to ensure to scan the stable magnetic field coupling between sensor excitation magnetic circuit and curved surface in-process, its characterized in that includes the following step:

1) the traditional micro-magnetic sensor mainly comprises a U-shaped electromagnet and a detection element, an excitation coil 10 is wound on a U-shaped magnetic yoke 16, the detection element comprises a Barkhausen noise receiving coil 17 and a Hall element 19 and is connected with a sensor shell through a fixing device 18, the U-shaped magnetic yoke is fixed by the shell of the sensor, an upper shell 5 and a lower shell 8 of the sensor are connected with a nut 9 through a screw 4, a baffle plate 11 is placed in the sensor and is connected with the upper shell and the lower shell of the sensor through a screw 3 and a nut 13, a position for placing a spring is arranged on the baffle plate, the other end of the spring is connected with the fixing device 18 of the detection element, and the detection element can be ensured to be tightly attached to a sliding shoe. All the lines in the sensor are connected to a thunder socket 6 and are connected with a power amplifier and a multifunctional data acquisition card through a thunder plug 7.

2) Customizing a sliding shoe according to the size of a micro-magnetic sensor and a tested piece, establishing a three-dimensional model of a part to be tested and a micro-magnetic sensor packaging shell in three-dimensional digital modeling software, adjusting the axis of the packaging shell to be coincident with the characteristic normal of the surface to be tested, setting the height of the end surface of the packaging shell and the surface to be tested, then drawing a three-dimensional entity intersected with the part to be tested and the micro-magnetic sensor packaging shell, eliminating the part to be tested and the micro-magnetic sensor packaging shell from the three-dimensional entity, designing a buckle structure assembled with the micro-magnetic sensor packaging shell to obtain a curved surface conformal sliding shoe three-dimensional entity, finally carrying out format conversion on a curved surface conformal sliding shoe three-dimensional entity file, inputting the curved surface conformal sliding shoe to a 3D printer, and manufacturing the curved surface conformal sliding shoe.

The invention can obtain the following beneficial effects: the micro-magnetic detection sensor is attached to the measured curved surface through the sliding shoe, so that the coupling of a stable magnetic field between a sensor excitation magnetic circuit and the curved surface in the scanning process is guaranteed, and the sensor can detect complex curved surfaces such as a crank shaft fillet and a hyperboloid spiral bevel gear tooth profile surface.

Description of the drawings:

FIG. 1: an overall schematic of the sensor detection at crankshaft fillets;

FIG. 2: a schematic diagram of a crankshaft round angle detection sensor and a slipper assembly;

FIG. 3: the detection sensor on the bevel gear and the sliding shoe assembly are schematically shown.

The reference numbers are as follows: 1-crankshaft 2-sliding shoe 3-screw 4-screw 5-sensor upper shell 6-rake socket 7-rake plug 8-sensor lower shell 9-fastening nut 10-exciting coil 11-baffle 12-spring 13-nut 14-spring 15-buckle 16-U-shaped magnetic yoke 17-Barkhausen noise detection coil 18-detection element fixing device 19-Hall element 20-sliding shoe 21-hyperboloid spiral bevel gear

The specific implementation mode is as follows:

according to the invention, a curved surface detection micro-magnetic sensor based on a conformal sliding shoe can provide the following implementation method.

On the conventional micro magnetic sensor, a 3D printed sliding shoe is fixed with the micro magnetic sensor through a spring 14 and a buckle 15 for coupling with a round corner of the crankshaft 1 to be measured. The micro-magnetic sensor with the sliding shoes scans the round corner of the crankshaft for a circle, the lifting distance from the crank shaft to the test piece is constant, and the sensor can detect the test piece at the fixed lifting distance.

The invention will be further described with reference to the following embodiments and drawings, and the following specific embodiments are provided for illustrative purposes only and are not intended to limit the scope of the invention.

Fig. 1 is an overall schematic diagram of the detection of the micro-magnetic detection sensor at the crank shaft fillet, the upper computer controls the amplitude and frequency of the excitation signal of the sensor, and the signal output from the upper computer is amplified by a power amplifier and then excites the excitation coil. When the exciting coil is introduced with a low-frequency alternating-current exciting signal, an alternating magnetic field is generated in the coil according to a Faraday electromagnetic induction law, the generated magnetic field passes through a sliding shoe along a magnetic yoke to form an alternating magnetic loop with a tested piece, so that a magnetic domain in the tested piece is overturned and moved to generate a magnetic Barkhausen noise signal, a Barkhausen noise detection coil in the sensor receives the magnetic Barkhausen noise signal, and a Hall element receives a tangential magnetic field signal and acquires the signal into an upper computer through a multi-channel data acquisition card.

Fig. 2 is the each subassembly sketch map of little magnetic sensor that crankshaft fillet department detected, wherein the lower surface of piston shoes is the curved surface unanimous with crankshaft fillet department size, consequently, piston shoes can laminate with crankshaft fillet department, piston shoes internal dimension is unanimous with little magnetic sensor shell latter half size, prepressing spring on the detecting element fixed part can guarantee that the interval of sensor and piston shoes assembling in-process magnetic field measuring subassembly and fitting surface keeps invariable, little magnetic sensor fixes through buckle and piston shoes, when detecting, the piston shoes move along with little magnetic sensor, when little magnetic sensor scans a week along crankshaft fillet department, little magnetic sensor is fixed with the lift-off distance of crankshaft fillet, little magnetic sensor can detect magnetic signal under fixed lift-off distance, thereby realize the detection to crankshaft fillet department.

Fig. 3 is a schematic diagram of a micro-magnetic sensor for detecting on a tooth profile surface of a hyperboloid spiral bevel gear, when a detected test piece is changed from a double arc surface at a crankshaft fillet to a tooth profile surface of a bevel gear, only a slipper at the tail end of the micro-magnetic sensor for detecting a curved surface needs to be customized again, and then the slipper is installed on a traditional micro-magnetic detection sensor to detect the tooth profile surface of the hyperboloid spiral bevel gear.

Claims

1. A curved surface detection micro-magnetic sensor based on conformal sliding shoes is composed of a U-shaped electromagnet, a magnetic field measurement assembly, a packaging shell and curved surface conformal sliding shoes, wherein the curved surface conformal sliding shoes are provided with end portions which are in conformal matching with curved surfaces of parts to be detected and sleeved at the tail ends of the packaging shell of the micro-magnetic sensor so as to ensure stable magnetic field coupling between a sensor excitation magnetic circuit and the curved surfaces in a scanning process; the U-shaped electromagnet is formed by winding an exciting coil on a U-shaped magnetic yoke, the magnetic field measuring assembly comprises a Barkhausen noise receiving coil and a Hall element which are fixed in the sliding chute, and a pre-pressing spring connected with the sliding chute 18 can ensure that the distance between the magnetic field measuring assembly and an assembling surface is kept constant in the assembling process of the sensor and the curved conformal sliding shoe; the curved conformal sliding shoe and the packaging shell are fixed through a buckle.

2. The method for designing a curved conformal slipper for a curved surface detection micro-magnetic sensor according to claim 1, wherein the curved conformal slipper is designed and manufactured by the following steps:

step 1: introducing a three-dimensional model of a part to be measured and a micro-magnetic sensor packaging shell into three-dimensional digital modeling software, adjusting the axis of the packaging shell to be coincident with the characteristic normal of the surface to be measured, and setting the height between the end face of the packaging shell and the surface to be measured;

step 2: drawing a three-dimensional entity intersected with the part to be detected and the micro-magnetic sensor packaging shell, eliminating the part to be detected and the micro-magnetic sensor packaging shell from the three-dimensional entity, and designing a buckle structure assembled with the micro-magnetic sensor packaging shell to obtain a curved conformal sliding shoe three-dimensional entity;

and step 3: and carrying out format conversion on the three-dimensional entity file of the curved conformal sliding shoe, inputting the file to a 3D printer, and manufacturing the curved conformal sliding shoe.