SU1589200A1 - Apparatus for ultrasonic inspection with variable angle of entrance - Google Patents

Abstract

This invention relates to acoustic methods of non-destructive testing. The purpose of the invention is to improve the accuracy and performance of determining the parameters of defects by providing an automatic intersection of the radiated ultrasonic (US) beam at different input angles at one point during scanning. The rack 10 with a magnetic holder 15 above the deflect 17 is fixed on the surface of the product 16 and the half-joint 11 is mounted on the rack 10 at a height corresponding to the depth of the defect 17. During the change in the distance between the uprights 10 and the housing 1 (scanning) the cylinder 12 of the guide element together with the bar 18 located in its opening 13, it rotates around its axis. Plank 18 through links 8 and 9 moves the hinge 5 in the guiding groove 3 of the housing 1 and through link 7 rotates the link 6 around the hinge 4. As a result, the angle of inclination of the piezoelectric element 14 changes so that its acoustic axis always reaches the defect point under study 17. 2 Il.

Description

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The slider 11 is pushed on a rack 10 at a height corresponding to the depth of the defect 1. During the change in the distance between the stand 10 and the housing 1 (scanning), the cylinder 12 of the guide element together with the bar 18 located in its opening 13 rotates around (its axis). Plank 18 through links

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8 and 9 move the hinge 5 in the guide slot. The housing 1 and through the link 7 rotates the link 6 around the hinge t. As a result, the angle of inclination of the piezoelectric element changes in such a way that its acoustic axis always falls at the studied cross-sectional point of the defect 17. 2 Il.

The invention relates to acoustic-non-destructive testing methods and can be used for ultrasonic (US) inspection of products when determining the parameters of a defect.

The purpose of the invention is to improve the accuracy and performance of determining the parameters of defects for the estimates of the intersection of the radiated ultrasound beam at different input angles at one point of the surface of the defect, which automatically occurs during the scanning of the product.

FIG. 1 shows a device for ultrasonic control with a variable angle of entry; in fig. 2 is a kinematic diagram illustrating its operation.

The control device with a variable insertion angle comprises a housing 1 with a working surface 2 and a guide groove 3 perpendicular to its working surface 2, and two hinges and 5 mounted in the housing 1 so that their axes of rotation are parallel to its working surface 2. The first hinge k is fixed in the housing 1 on a line extending from the groove 3 to the working surface 2 of the housing 1, and the second hinge 5 is mounted for movement along the guide groove 3f. The device also contains the first link b, which interacts with the hinge i, the second link 7 , interacting with the hinge 5, the third link 8, interacting with the hinge 5, and the fourth link 9, interacting with the hinge it. In addition, the device comprises a rack 10 mounted for movement along the rack 10 and fixing a slider 11 thereon and a guiding element made in. the form of a cylinder 12 with a hole 13, installed

rotary wok

Own its axis on the slide 11. The axis of rotation of the cylinder 12 is parallel to the axis of rotation of the hinges k and S- The hole 13 of the cylinder 12 is perpendicular to its axis of rotation and passes through it. The device also contains a piezoelectric element lA, a rigid member associated with link 6 so that its acoustic axis is parallel to the bar 6, and

the axis of rotation passes through it

the center and the magnetic holder 15 fixed on the rack 10 in such a way that when it is mounted on the test item 16 with a defect 17 the stand 10 is arranged in parallel

° groove 3 of the housing 1. Link 6-9 form a hinged parallelogram, in the form of which the mechanism of rotation of the piezoelectric element k is made. The device also contains a guide bar.

5 to 18, passing through the opening 13 of the cylinder 12 and rigidly connected to the link 9. The lengths a and b of links 7 and 9, 6 and 8, respectively, are selected from

ratios 40

a / b sino (/ sin / 5,

where d is the angle of entry of ultrasonic vibrations in

the material of the product I6j 5 U is the angle of incidence of the ultrasonic vibrations on the working surface 2 of the housing 1;

 - the speed of propagation of ultrasonic vibrations in material 50 of item 1b

WITH . - the speed of propagation of ultrasonic vibrations in the material

housing 1 in the area from piezoelement lA to working surface 55 of housing 2.

Device for ultrasonic control with a variable angle input works as follows.

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For the defect 17 of the product 16 fixed with the conventional ultrasound control, the depth is determined and a spot is placed on the surface of the product 16 above the defect 17. Install a device on the surface of the product 16 so that the stand 10 with the magnetic holder 15 is above the defect 17 Install a slider 11 on the rack 10 to a position corresponding to the depth of the detected defect 17 (for convenience, a scale is applied on the rack 10) and fix it in this position. The body 1 is moved along the surface of the product 16 from position I to position II (Fig. 2), changing the distance between the pillar 10 and the housing 1. In this case the cylinder 12 of the guide element rotates around its axis and causes the guide bar 18 inserted into its opening 13 to rotate. The bar 18 through the links 8 and 9 causes the hinge 5 to move in the guide slot 5, as a result of which the link 7 transmits rotational motion to link 6 and piezoelectric element 1 rotates relative to the axis of the hinge 4. The angle of inclination of the piezoelectric element I varies with the rotation mechanism with changing distance so that its acoustic axis always hits test point of defect section 17. The intersection of acoustic rays at one point is caused both by the choice of lengths a and b of links 6 to 9 parallelogram depending on the speed of propagation of ultrasonic vibrations in the materials of product 1 and body 2, and by the distance from a plane parallel to the surface the controlled product 16 and passing through the geometric center of the piezoelectric element C to the axis of rotation of the cylinder 12, equal to the depth of the defect 17, increased by the height of the imaginary radiator above the surface of the product 16. Increasing It is caused by the need to take into account the path traveled by ultrasonic vibrations in housing 1, and is carried out by bringing the actual radiation nf - 2 to a minimum (, A 5 in FIG. 2) located on the continuation of the beam in the material of iziel 16 into the housing 1, by a distance equal to the actual path of the ultrasonic oscillations in the housing 1, reduced in relation to the speed ratio

.c 15 20

30 о 35 в 40 D p zo you 45 lo ra on le mo 50 l pa it’s not the same

55

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spreading 3 vibrations in materials of housing 1 and controlled product 16. In the process of moving housing 1, piezoelectric element 1 / radiates 16 ultrasonic vibrations into product and receives echoes reflected from defect 17, their amplitudes are measured for each new position of piezoelectric element C, an amplitude versus angle of entry curve is obtained and the configuration and orientation of the defect are determined from the shape of the curve.

MP J ;; r ° was used with an ultrasound transducer with a variable input angle, including a prism with an aperture and a conical or cylindrical rotary insert with a piezoelement placed in it.

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Claims (1)

Invention Formula A device for ultrasonic testing with a variable entry angle comprising a housing with a working surface, a piezo element installed in the housing, and a piezoelectric rotation mechanism associated with it, characterized in that, in order to improve the accuracy and productivity of 30 determination of defect parameters, it is equipped with a durable a slider mounted for movement along the stand and fixing on it mounted on the slider for 5 rotation around its axis by a guide element made in the form of a cylinder with an opening Perpendicular to the axis of the cylinder and passing through it, and a guide bar that passes through the cylinder bore, the body is made with a guide groove perpendicular to its working surface, the rotation mechanism of the piezoelectric element is made in the form of a hinge parallelogram, two the opposite hinge of which is mounted on the body on one straight line, one of them is fixed and the other is movable along the directional groove of the body, one link of the parallelogram interacting with the fixed The hinge is rigidly connected with the guide bar, another link interacting with the fixed hinge is rigidly connected with the piezoelectric element so that its acoustic axis is parallel to this link and the axis of rotation passes through its center. vv  - -b-: 0 "M L)