RU118758U1 - DEVICE FOR ULTRASONIC CONTROL OF LONGITUDINAL WELDED JOINTS BY MANUAL LONGITUDINAL-CROSS-SCAN WITH MAGNETIC FASTENING - Google Patents

Abstract

A device for ultrasonic testing of longitudinal welded joints with manual longitudinal-transverse scanning with a magnetic mount, containing a main guide, a carriage mounted on the main guide, an additional guide fixed on the carriage perpendicular to the main guide, a slider interacting with an additional guide and a prismatic transducer with a clamping unit, characterized in that it is equipped with a second additional guide fixed in the carriage parallel to the first additional guide, an additional slider installed parallel to the main slider on additional guides, an additional prismatic transducer with a clamping unit, a support base with a bed in the form of rollers and with two magnetic racks along the axis of the cradle , a lead screw with a knurled head, fixed in the carriage parallel to additional guides with the possibility of rotation around its own axis and interacting with the main and additional sliders, while in the grooved head of the lead screw there is a retainer in the form of a rod pressed by a spring against the carriage wall, the main guide is made in the form of a flat plate with a longitudinal window through which the prismatic transducers contact the surface of the input-receiving of ultrasonic vibrations into the welded joint of the product , and is equipped with end fasteners to the product in the form of magnets in cylindrical casings, coinciding with the magnetic posts, linear scales are applied on the side walls of the main guide and the carriage.

Description

The utility model relates to the field of ultrasonic quality control of welded joints, in particular to manual control by longitudinal-transverse scanning of longitudinal butt welded joints made by electron beam welding, and is intended for use in products in the form of bodies of revolution made of non-magnetic materials, and can be found widespread use in various engineering industries.

A device [1] is known for ultrasonic testing of welded joints by longitudinal-transverse scanning, comprising a guide, a carriage, a rod movably mounted on the carriage, and a transducer with a clamping mechanism mounted on the rod, an axis mounted on the carriage with the possibility of rotation, rigidly installed on it the disk and the gear and the stops mounted on the guide and interacting with the program disk during the control, and the rod is made in the form of a gear rack, which engages with the gear.

The device has serious drawbacks. It is intended for ultrasonic testing of welded joints of structures whose welded parts have magnetic properties and is not suitable for quality control of welded joints of non-magnetic parts of a product. The clamp nodes of the transducer to the surface of the controlled structure and the fastening of the guide are made in the form of magnets. Software disks that provide a given value of the transverse scan step of the transducer have a complex structure, and a set of such disks is required to control welds of different thicknesses. At the beginning and end of a longitudinal scan, the transducer cannot provide the necessary accuracy in determining the depth of occurrence of detected defects. In addition, the device cannot provide combined control of the welded joint simultaneously by two methods.

Another device [2] for ultrasonic testing of welded joints is also known, comprising a guide with end stops, a trolley (carriage) mounted on the guide, an additional guide fixed to the carriage perpendicular to the main guide, a slider interacting with the additional guide, a vertical strut mounted on a slider, an inclined (prismatic) finder (transducer) with a clamping device, mounted on the slider, while the end stops of the main guide are made in in the form of a plate with sawtooth teeth of various widths, determined by the scanning step.

This device has a more simplified design and manufacturing technology in comparison with the previous device, because it does not have a set of software disks. However, the disadvantages of the previous device remain, and there are disadvantages. The clamp unit of the transducer to the input surface of ultrasonic vibrations and the device are designed to control the welded joints of magnetic materials. The stops of the main guide in the form of a plate with sawtooth teeth of different widths do not provide the accuracy characteristics of the transverse movement of the ultrasonic transducer, which depend on the speed of longitudinal movement. In addition, due to the teeth of different widths at the beginning and at the end of the longitudinal movement of the transducer, uncontrolled zones of the welded joint are preserved, which can lead to the passage of defects along the depth of the welded joint. In this case, the device cannot be used for combined ultrasonic testing simultaneously by two methods, for example, mirror-shadow and echo-pulse.

Despite the shortcomings, the device with an additional guide in its design is the closest analogue of the proposed utility model, so it is taken as a prototype.

The objective of the utility model is to create a device for ultrasonic quality control of welded joints of products made of non-magnetic parts, to ensure transverse transducer movements in the control process with a constant step, to exclude uncontrolled zones at the beginning and at the end of the transducer longitudinal movement, to read the coordinates of the longitudinal and transverse transducer movements, fixing the main guide when controlling welded joints of non-magnetic products to them using magnets, identifying volumetric and planar defects such as cracks, lack of fusion and oxide captured through the thickness welds, determining the depth of the detected defects.

The problem is solved as follows.

The device is equipped with a second additional guide fixed in parallel with the first additional guide, an additional slider, an additional prismatic transducer with a clamping unit, a threaded spindle with a knurled head, an additional guide mounted in the carriage in parallel with the possibility of rotation around its own axis, interacting with the sliders, and, through them, clamping devices with prismatic converters. The main guide is made with a longitudinal window through which the transducers are in contact with the surfaces of the input-reception of ultrasonic vibrations into the product of a controlled welded joint. The side walls of the main input-reception guide are made stepwise. On one of the side walls of the main guide and on the side walls of the carriage, linear scales are applied for reading the coordinates.

Applicants are not aware of the use of the distinguishing features of the proposed manual scanning device with the achievement of these results.

The essence of the utility model and its work are illustrated by graphic materials, which show:

figure 1 - General view of the device;

figure 2 is a section aa in figure 1;

figure 3 is a section bB in figure 1;

figure 4 is a cross-section bb in figure 1;

figure 5 - mounting the main guide on the product;

in Fig.6 is a view of G in Fig.5.

The device comprises a main guide 1 (Fig. 1), mounting nodes 2 in the form of magnets (Fig. 3), a carriage 3 (Fig. 1, Fig. 2, Fig. 3) with rollers 4. The main guide 1 (Fig. 1) It is a plane-parallel plate with a longitudinal window 5, the side walls 6 of which are stepped. A linear scale is marked on one of the walls 6. On the end walls 8, risks 9 are applied. The fixing units 2 (Fig. 3, Fig. 5, Fig. 6) are mounted in pairs on the end walls 8 of the window 5 of the guide 1 and are moved outside the welded joint along its length they contain disk or ring magnets 10 (Fig. 3) in cylindrical cages 11. The carriage 3 (Fig. 1, Fig. 2, Fig. 3) includes a support frame 12 with side walls 13 and 14, on which linear scales 15, end walls 16 and 17, the first additional guide 18 and the second additional guide 19, installed per perpendicular to the main guide 1, the main slider 20 and the additional slider 21 with covers 22 and fixing screws 23 (FIG. 2, FIG. 3), interacting with the guides 18 and 19, clamping units 24 and 25, prismatic transducers 26 and 27 with local baths installed counter-to each other, the lead screw 28 (Fig. 1, Fig. 2, Fig. 3) with a knurled head 29, mounted in the end walls 16 and 17 of the carriage 3 with the possibility of rotation around its own axis and interacting with the sliders 20 and 21, which, when the screw 28 is rotated, simultaneously move along its axis. In the slider 21, a split nut 30 (FIG. 3) is installed with an expandable assembly including a tick-shaped device 31, one ends of which are rigidly connected to the split nut 30, and the other are unclenched by a spring 32 and interact with the pins 33. The clamping units 24 and 25 (FIG. 2) converters 26, 27 contain two rods 34 (figure 3) with spherical bearings 35 and two springs 36. In the corrugated head 29 (figure 4) there is a latch, including a rod 37 with a semicircular end, pressed by a spring 38, and in the front wall 16 of the carriage 3 there is a hemispherical recess 39. In Fig.5 and Fig.6 presents lodgement (workstation) for conducting ultrasonic testing in a cylindrical product 40 of a longitudinal welded joint 41, containing a base 42, on which support posts 43 with rollers 44 and magnetic posts 45 that are mounted for rotation around their axes and mounted on the main 40 guide 1 using its magnets 10.

The device operates as follows.

Before starting the inspection, the product 40 with the controlled welded joint 41 is installed on the rollers 44 of the cradle with the help of a workshop bridge crane so that the welded joint 41 coincides with the axial risks (not shown in FIG. 5 and 6) of the magnetic posts 45. The clamping unit ( figure 5 and figure 6 is not shown) fix the product 40 in the installed position. The main guide 1 is introduced into the internal cavity of the product 40 so that the risks 9 (Fig. 1) on the end walls 8 of the longitudinal window of the guide 1 coincide with the longitudinal axis of the welded joint 41 of the product 40 so that the mounting magnetic units 10 (Fig. 5, 6) the guide 1 coincided with the magnetic racks 45 of the base 42 of the lodgement. In the carriage 3, ultrasonic transducers 26, 27 are installed in the sliders 20 and 21, opposite each other, passing the cables and polyethylene tubes of the local baths of the transducers 26 and 27 into the holes of the sliders, inserting the ball bearings 35 of the spring-loaded pins of the sliders 20 and 21 into the blind holes of the transducers 26 and 27 Fasten the cover 22 of the sliders 20 and 21 with screws 23 (figure 2, figure 3). Then, in the carriage 3 using the lead screw 28 on a scale of 15 set the slider 20 on the division corresponding to the formula:

where: S is the distance between two transducers installed opposite each other;

t is the thickness of the controlled weld;

α is the angle of entry of ultrasonic vibrations into the heat-affected zone during the quality control of the welded joint.

Pressing the pins 31 of the slider 21, displace it along the spindle 26 and the guides 18 and 19 to the beginning of the scale 15 and set to zero division. The carriage 3 is installed with rollers 4 on the lower steps of the side wall 6 of the longitudinal window 5 of the guide 1. Make sure that it moves freely along the guide 1 and in the absence of lateral vibrations of the carriage 3 when it moves along the guide 1. Connect the transducer cables 26, 27 to the flaw detector ( 1, 2, 3, 4, 5, 6 is not shown), and the feed tubes of the local baths of the transducers 26, 27 are connected to the feed tank (not shown in Figs. 1, 2, 3, 4, 5, 6) with contact liquid (water). They turn on the power of the flaw detection equipment, make sure that there is a pulse on the screen from the transducer 27. The carriage is shifted to the extreme position, for example, to the left (Fig. 3) along the main guide 1 until it stops and then the weld joint 41 is monitored, shifting the carriage 3 to the right (figure 1, figure 3) along the guide 1 to the stop. Having reached the stop to the right, turn the knurled head 29 of the lead screw 28 one turn to the left, when a slight click of the lock is felt, the carriage 3 begins to shift to the left along the guide 1, while the ultrasonic transducer 27 will be shifted 1 mm further from the axis of the welded joint 41. B the leftmost position of the carriage 3 on the guide 1, the prismatic transducer 27 is rotated by turning the knurled head 29 of the lead screw 28 again 1 mm further from the longitudinal axis of the welded joint 41. And so each time in the extreme position of the carriage 3 to the right or Eva of its longitudinal movement along the main guide 1, the ultrasonic transducer 27 is displaced 1 mm away from the longitudinal axis of the welded joint 41, until the transducer 27 is displaced from it by a distance equal to the thickness of the welded joint 41. In this case, the transducer 26 approaches the same distance to the axis weld 41.

If a defect is detected in the welded joint 41 on the scale 7 of the main guide 1, its X coordinate is determined, and on the scale 15 of the guides 18 or 19 (FIG. 1, FIG. 3), the Y coordinate of the transducer 27 is determined at the time of detection of the defect by the transducer 26 relative to the ultrasonic input surface oscillations of the heat affected zone. If the defect is volumetric and is additionally detected by the transducer 27 by the echo method, the flaw detector determines its value by the reflectivity of the defect and its distance from the point of entry of ultrasonic vibrations, and the occurrence depth is calculated by the flaw detector according to the formula:

where: h is the depth of the detected defect;

L is the distance of the defect from the point of entry of ultrasonic vibrations;

α is the angle of entry of ultrasonic vibrations into the metal of the heat-affected zone.

If the defect is flat and is detected only by the transducer 26 by the mirror-shadow method, its value is determined by the length of the defect along the welded joint and by the length (thickness), and the depth of the beginning and end of the defect is calculated by the flaw detector equipment according to the formula:

where: h is the depth of the defect (beginning or end);

Y is the coordinate of the transducer at the time of detection of a defect or at the time of its disappearance (end of defect);

α is the angle of entry of ultrasonic vibrations into the metal of the heat-affected zone.

Thus, the proposed device solves the tasks before the utility model: it provides a uniform step of transverse transducer movement, parallelism of the paths described along the longitudinal welded joint, eliminates uncontrolled zones at the beginning and at the end of each longitudinal scan of the converter. The main guide is securely fastened at the ends to the tool posts, at the same time to the product of a controlled welded joint. The device provides for the detection of volume defects and plane defects in the form of cracks, imperfections and oxide films throughout the thickness of the welded joint, the longitudinal and transverse coordinates of the synchronous movement of the two transducers are read out, and the magnitude and depth of the defects are calculated using the formulas.

Information sources.

1 RF Patent No. 1182383, cl. G01N “Device for manual ultrasonic inspection of welds by longitudinal-transverse scanning”, published on 09/30/1985.

2 RF Patent No. 1174851, cl. G01N “Device for ultrasonic inspection of welds”, published on 08.23.1985.

3 Manual devices for longitudinal-transverse scanning for ultrasonic testing of butt welded joints // Visual aid. - LDNTP. - 1986 - 191011 Leningrad, Nevsky Prospect, 58.

Claims (1)

A device for ultrasonic testing of longitudinal welds by manual longitudinal and transverse scanning with magnetic fastening, comprising a main guide, a carriage mounted on the main guide, an additional guide fixed to the carriage perpendicular to the main guide, a slider interacting with the additional guide and the prism transducer with a pressure unit, characterized in that it is provided with a second additional guide fixed in the carriage parallel to the first an additional guide, an additional slider mounted parallel to the main slider on additional guides, an additional prismatic transducer with a clamping unit, a support base with a lodgement in the form of rollers and with two magnetic posts along the axis of the lodgement, a spindle with a grooved head fixed in parallel to the carriage with an additional guide with the possibility of rotation around its own axis and interacting with the main and additional sliders, while in the grooved head of the chassis in Inta made a clamp in the form of a rod, spring-loaded to the wall of the carriage, the main guide is made in the form of a flat plate with a longitudinal window through which the prismatic transducers are in contact with the input surface of ultrasonic vibrations in the welded joint of the product, and is equipped with end fastening nodes to the product in the form magnets in cylindrical clips matching magnetic racks, linear scales are plotted on the side walls of the main rail and carriage.