SU789743A1 - Ultrasonic transducer with local chamber - Google Patents

Description

I

The invention relates to the field of non-destructive testing of products and can be used in any industry of machine-building, in particular in the control of sheets of large thickness going to the manufacture of high-pressure vessels.

In the control of thick-walled products, an urgent task is to identify misoriented defects.

A multi-element acoustic device for quality control of welded joints is known, which contains a local bath, a housing, inside which a holder is fixed on the motor axis. Pa holder, the axis of rotation of which is perpendicular to the working surface of the device, has inclined prismatic finders with different angles of inclination, and in the center is a normal finder 1.

The disadvantage of the device is that a system of rotating finders is used to implement the swing beam method. Their multiple elements complicate monitoring and reduce its reliability; the change in the input angle of ultrasonic vibrations is discrete rather than smooth.

In addition, when rotating the cage with the searchers, the contact fluid is thrown to the periphery of the local bath, to create a reliable acoustic contact, a significant increase in the contact fluid flow is required.

The closest to the proposed technical essence is

to an ultrasound transducer with a local camera, comprising a housing and a piezoplate placed therein and a mechanism for changing its position 2. The disadvantage of this converter is low productivity due to manual change of the input angle of ultrasonic vibrations.

The purpose of the invention is to automate the change of the input angle of

20 vibrations.

The goal is achieved by the fact that the mechanism for changing the position of the piezoplastin is made in the form of an electric motor and is kinetically bound to

25 them two gears, the output shaft of one of which is connected by means of a spherical hinge with the center of piezoplate, and the second gearbox is rigidly fixed on it, o

A gear 30 concentric with the output shaft of the first gearbox, a rod with a rock at the end interacting with a piezoplastin, while the rod is displaced relative to the axis of the piezoplate along its radius. FIG. 1 shows a general view of the device; in fig. 2 is a section A-L in FIG. one; FIG. 3 is a view along arrow B of FIG. 2, the transducer contains a cylindrical body 1g with a local chamber 2, which has double walls and is made with perforations 3 and 4 in the inner wall. Itzer 5 is intended to be connected to the main line of contact fluid 6, which comes under pressure and penetrates through the perforations into the annular container between the walls of the housing. The local bath contains a protector 7 made of elastic material with high capillary porosity, for example, microporous rubber, which fills the volume bounded by the inner wall of the housing 1 and the piezoplate. On the pieopoplast 8 there is a disk 9, around the perimeter of which the corrugated elastic tube 10 is fixed, with the upper edge hardwired. with the walls of the local bath, with the result that between the latter and the housing 1 is formed tight; cavity. The mechanism for changing the position of the piezoplate is made in the form of a reversible electric motor 11 and two gearboxes kinematically connected with it, the first of which consists of gears 12-14, nut 15, housed in gear 14, and screw 16, the end of which is the output shaft of the gearbox and connected by means of a spherical hinge 18c to the center of the piezoplate 8. At the end of the screw 16, the stop 19 of its stroke is fixed, which interacts with end switches 20 and 21 in the control process, while the screw 16 has a key 22 and a flat face 23 on which the scale 24 is applied, for example ep in degrees, defining an input angle -Shestern ultrasonic vibrations. 13 is mounted on a movable axis 25 with a handle 26 and a latch 27. The second gearbox is designed in the form of gears 2.8 ,, the electric motor 11 rigidly mounted on the shaft 11 and the gear 29 which is permanently engaged with it is concentric with the output shaft 17 The first gearbox. On gear 29, perpendicular to its surface, rod 30 is rigidly fixed with roller 31 at the end interacting with piezoplate. Through disk 9 rod 30 is shifted relative to the center of piezoplast B to its radius. A roller position indicator 32 is mounted on the rod 30, and a viewing glass 33 on the housing 1. Before controlling, the converter is placed on the product 34. The converter operates as follows. It is connected to a flaw detector (not shown) and the contact fluid is fed through 6 through a fitting 5 into an annular container between the outer and inner wall of the housing, forming a local chamber. Through the perforations 3, the contact liquid permeates the elastic capillary material of the tread 7, which, when in contact with the product 34, is somewhat compressed. The contact liquid is squeezed onto the surface of the product, thereby providing an acoustic contact, in the creation of which also the openings 4 in the bottom of the body are involved. After such preliminary preparation, the motor 11 of the mechanism for changing the position of the piezoplate 8 is lowered. When axle 25 is lowered, the rotation of the motor shaft is transmitted through an intermediate gear 13 gear 14 interacting with a screw pair, the screw 16 of which moves transversely within the limits of the end switches 20 and 21 periodically in contact with the limiters 19. The switches 20 and 21 change the direction of rotation of the shafts of the electric motor 11. As the screw 16 moves, the translational movement its ends 17 (for example, are raised), thereby changing the angular position of the disk 9 and, consequently, the piezoplates 8, thus rocking the ultrasonic beams in a plane perpendicular to the plane of the product 34. At the same time, the ultrasound beams are rocked in the plane parallel to the product, since the rotation from the shaft of the electric motor 11 is transmitted through gear 28 to gear 29, on which rod 30 is eccentrically mounted, carrying roller 31, while roller rolls along disk 9, tube 10, which serves to exclude ADANI couplant into the inner cavity of the housing 1 is deformed due to corrugations in each .moment roller 31 under the action of piezoceramic plates 8 varies 34.Nahod article-adhesive area in the pores of the tread 7, the liquid improves the acoustic contact between the product and proobra.zovatelem. At this time, in all other zones of the protector, the pores, having a rounded shape, scatter ultrasonic vibrations and simultaneously adsorb the contact fluid 6 from the perforation 3 through the perforation 3. In this case, the unstressed area of the tread material 7 performs the functions of a scattering ultrahigh; ultrasonic traps, so that the refracted / ultrasonic beams at the protector-surface interface of the monitored product do not fall as an acoustic disturbance to the piezoelectric plate operating at this time in the oscillation reception mode. In addition, the transducer in this zone does not emit ultrasonic oscillations into the product, which allows to eliminate the reflection reflection from the structural elements of the local bath. , The roller 32 and the sight glass 33 serve to track the roller 31.

The converter works. in automatic mode.

If it is necessary to re-check with a fixed angle of input of ultrasonic vibrations, the handle 26 is lifted vertically upwards and fixed with the aid of the lock 27, while the axis 25 from the rigidly connected gear 15 rises and the gear 12 goes out of engagement with the gear 14.

In this case, the angle of the converter remains constant. The tilt angle is marked on a scale of 24 on the screw 16, which moves progressively due to the key 22.

 The replayer will increase the productivity of detecting misoriented defects in the shuttle scanning process with a relatively simple design and ease of use.

The automation of the oscillation of ultrasonic beams in two mutually perpendicular planes is provided here with only one transducer and without its rotation. The possibility / separate operation of the mechanisms provides the necessary control options.

Claims (2)

1. USSR author's certificate 406156, cl. G 01 P 29/04, 1974., 2. USSR author's certificate W 139138, cl. G 01 M 29 / 04,1961 5 (prototype). //// Z / y / W ////// ig.1 KK J FIG. 2 & iZb