KR102339444B1 - Ultrasonic Probes and Ultrasonic Inspection Systems - Google Patents

Abstract

The probe 100 for an ultrasound inspection system for non-destructive material inspection during the relative movement of the inspection object with respect to the probe along the inspection direction is a longitudinal direction (L) in the inspection direction and a lateral direction (Q) perpendicular to the inspection direction and a probe housing 110 defining Each transceiver has a transmitter element (T1, T2, T3) and an assigned receiver element (R1, R2, R3), the test track having an effective test width (PB1, PB2, PB3), the probe along the test direction Defines the effective inspection width in the transverse direction (Q) so that it can be inspected by the transceiver during the relative movement of the inspection object to . The transceivers are disposed in at least two rows 155 - 1 and 155 - 2 which lie in front of and behind each other in the longitudinal direction (L) and proceed in the lateral direction (Q). Transceivers from different rows overlap each other in the overlap region U1-2, U2-3 so that the receiver elements R1, R2, R3 of the transceivers offset with respect to each other overlap each other so that the transceivers together are in any gap offset with respect to each other in the transverse direction Q, to cover the effective probe test width PKPB without All of the transceivers are disposed in the probe housing 110 . All of the transmitter elements T1 , T2 , T3 are electrically connected to the common transmitter terminal element AT of the probe.

Description

Ultrasonic Probes and Ultrasonic Inspection Systems

The present invention relates to a probe for an ultrasonic inspection system for non-destructive material inspection during relative movement of an inspection object with respect to the probe in an inspection direction.

Ultrasonic inspection is an acoustic process for determining device dimensions by means of ultrasound, looking for material defects known as discontinuities. It is classified as a non-destructive testing method. In non-destructive material inspection by means of ultrasound (US), sound is transmitted from a probe to an inspection object through a bonding medium, such as a liquid film. Transmission of ultrasonic waves carrying information about the condition of the material being inspected from the inspection object to the receiving probe generally occurs via the same coupling medium. Separate transmit and receive probes may be used to emit and receive ultrasound or ultrasound pulses. A probe is here understood to mean a handling unit in which one or more ultrasonic transducers are installed. The ultrasonic transducer itself is an element that converts an electrical signal into a sound signal (sound signal) or converts a sound signal into an electrical signal. Usually, sound-emitting and sound-receiving ultrasound transducers are combined into one probe. If they are separate transmitters and receivers, they are also referred to as transmit/receive probes or transceiver probes. These are preferred whenever, for example, a large near field resolving power is required. If the same ultrasonic transducers are used for transmitting and receiving, these transducers are referred to as pulse-echo probes.

Transceiver probes (transceiver probes) are used, for example, for ultrasonic inspection of metal plates. These probes generally have a typical width of 1 m to 5 m, a typical length of 3 m to 30 m and a typical thickness of 5 mm to 150 mm. Paper, "Operational experience with a new whole-plate ultrasonic testing system" (A. Weber et al., DGZfP Annual Meeting 2013 - Di.2.B.2, pages 1-8 ) describes a full-plate ultrasonic inspection system which is placed in a rolling mill immediately downstream of a cooling bed at the inlet to the shearing section. In all, 76 individually pneumatically actuated probe holders fit into the described ultrasound examination system. A transceiver probe with a nominal frequency of 5 MHz is used. The multiple oscillators used were 50mm wide and divided into four, which meant that there were 304 test channels that had to be dealt with individually. The probe holders are mounted on two surface inspection carriages which are positioned behind each other in the inspection direction and offset from each other by the width of the probe in the transverse direction. Eventually, according to this paper, full surface area inspection (100% inspection) is achieved.

A known transceiver probe divided into four has a single transmitter element and a row of four receiver elements disposed next to each other within a probe housing having a rectangular cross section, the single transmitter element extending over the entire width covered by the receiver element do. As a result, for example, a reference defect of FBH-3 (Flat Bottom Hole-3: 3 mm diameter flat bottom hole) grade can be detected with high reliability. However, in the case of, for example, metal plate inspection, there is also an increasing need to detect smaller defects such as FBH-2 or FBH-1.2 with high reliability.

Published patent application DE 195 33 466 A1 states that at least two parallel rows each offset relative to one another by this gap, such that each gap between the ultrasonic transducers in one row is covered by the ultrasonic transducers in the other row. An ultrasonic probe for non-destructive material inspection is disclosed, comprising a plurality of pulse-echo ultrasonic transducers disposed with their transmit/receive surfaces in one plane. This results in a probe with a large inspection width, which probe has a very constant sensitivity over the entire inspection width.

Published patent application DE 34 42 751 A1 is for an ultrasonically operated metal sheet, which can be set in a metal sheet and superimposed on each other in a row in a row transverse to the transport direction of the metal sheet and in a plurality of rows in the transport direction An inspection system comprising a plurality of probes provided back and forth is disclosed. Each probe has a transmitter and a receiver.

Published patent application DE 196 42 072 A1 discloses a combined probe device with multiple receive oscillators arranged in staggered fashion on either side of a common transmit oscillator. The transmit and receive oscillators are constructed with a common piezoelectric plate, one of the electrodes of these oscillators being separated. The receive oscillators in different rows partially overlap laterally, allowing inspection over the entire length covered by the transmit oscillators without any gaps.

Published patent application DE 10 2008 002 859 A1 discloses a device for non-destructive inspection of sheet-like articles by ultrasound, which device uses a matrix-phased-array probe.

The present invention is, for example, a probe suitable for use in ultrasonic metal plate inspection systems, easy to handle and install in inspection systems, while allowing inspection of large inspection widths without any gaps with high reliability even for small defects in inspection objects to solve the problem of providing

In order to solve this problem, the present invention provides a probe having the characteristics of claim 1. Advantageous improvements are specified in the dependent claims. All claims are incorporated herein by reference.

The probe has a probe housing defining a longitudinal direction and a transverse direction perpendicular thereto. The longitudinal direction is the direction that is aligned as parallel as possible to the inspection direction during operation. The transverse direction runs perpendicular to the longitudinal direction and is consequently as perpendicular to the inspection direction during the inspection operation as possible. The probe has a plurality of transceivers and thus becomes an ultrasonic multi-probe. Each transceiver has a transmitter element and an assigned receiver element. Consequently, the effective inspection width is defined transversely such that an inspection track having the effective inspection width can be inspected by the transceiver during relative movement of the inspection object with respect to the probe along the inspection direction. The effective inspection width is generally somewhat smaller than the physical extent of the transceiver in the transverse direction, which is when the sensitivity of the transceiver usually drops sharply near the lateral end, so that in fact only slightly smaller inspection widths are useful. The transceiver units are arranged in at least two rows which lie before and behind each other in the longitudinal direction and respectively proceed in the transverse direction. The transceivers from different rows are offset from each other laterally such that the receiver elements of the transceiver that are offset from each other overlap each other in the overlapping area such that the transceivers collectively cover the effective probe test width without any gaps. Both the transceiver and the transceiver are disposed in the probe housing.

All of the transmitter elements are also provided to be electrically coupled to a common transmitter terminal element of the probe. The transmitter elements are in turn electrically connected to each other and can be easily activated synchronously by a common signal. The synchronization of the transmit signal is in turn already provided by the configuration of the probe and need not be ensured by complex electronics.

Although more than two rows each having one or more transceivers may be provided, the transceivers are preferably arranged in exactly two rows which lie before and after each other in the longitudinal direction.

Because both the transceivers are placed together in the probe housing, the transceivers can be precisely brought into the positions intended for these transceivers within the probe housing during probe manufacturing, and the relative positioning of the transceivers to each other can be established accurately. . The geometry of the transceiver within the probe housing is generally established by a carrier element, eg by introducing a suitable potting compound, such as an epoxy resin, permanently spatially fixed and protected from intrusion of the bonding medium.

The mutual overlap of the effective test widths of the individual transceivers can in fact be achieved by mounting the transceivers each in their own probe housing, and the thus obtained individual probes being positioned offset from each other in two or more rows within the probe holder. . Corresponding examination, however, has shown that with such binding of multiple individual probes, it can be difficult to precisely and sufficiently set the desired binding gap for each probe separately within the probe holder. On the other hand, if both the transceivers are located in the same probe housing, the relative arrangement of the transceivers to each other can be precisely fixed already during probe manufacturing, so that when the probe is installed in the probe holder, the setting of the coupling gap is quick and It can be executed precisely. Consequently, the direct comparability of the signal amplitudes of the reference defects of both the transceiver and the transceiver of the probe is ensured.

That only that area of the theoretically available inspection width with sufficiently high sensitivity is used by each transceiver can be ensured by mutual overlapping of the transceivers in the lateral direction which are offset with respect to each other in the overlapping area. The width of the mutual overlap is such that regions having a sensitivity drop in the immediate vicinity of the side edge of the transceiver are overlapped with each other, so that a decisive drop in sensitivity between the transceiver adjacent in the lateral direction is avoided or conventionally arranged in a single row. It is chosen for convenience in this case, so that it is significantly reduced compared to multiple oscillators. In some exemplary embodiments, the overlapping area has a width of at least 10% of the effective check width of the respective transceivers, and this width of the overlapping area preferably ranges from 20% to 30% of the effective check width. If these limits are maintained, on the one hand, it can be ensured that the overlap is sufficient to prevent a significant drop in sensitivity in the overlap region. On the other hand, by not selecting the overlapping area to be too wide, the effect that the required overall inspection width (effective probe inspection width) of the probe can be achieved with relatively few individual transceivers can be achieved.

In some embodiments, the arrangement is selected such that, between adjacent transceivers in a row, there is a spacing greater than 30% or more than 50% of the effective check width of the transceivers. In this way, in principle, it can be ensured that no useful inspection widths are "abandoned" or that only a few small inspection widths are "abandoned".

The transmitter element and the receiver element preferably in each case have a platelet of piezoelectric material, for example a rectangular platelet, which in the case of the transmitter element acts as a sounding ultrasonic transducer, the receiver element In this case, it acts as an acoustic ultrasonic transducer. These platelets are elements separated from each other and each provided with electrical contact. In a preferred embodiment, these platelets or plates are arranged at an angle relative to one another, so as to obtain a roof shape formed mirror-symmetrically with respect to the dividing plane. The separation plane extends transversely. The roof angle is for example 6°, but more or less may be possible.

In the separation plane between the ultrasonic transducers (the plane of symmetry of the roof arrangement) there is preferably a separating wall of ultrasonic damping material. One of its purposes is the acoustic separation of the transmitter element and the receiver element of the transceiver, so that sound transmission can only occur indirectly through the material of the test object coupled thereto during the test. The separation wall may also serve as electrical isolation of the ultrasonic transducer on the transmit side and the receive side.

The advantage of this new concept can already be used when only the two transceivers are arranged in the probe housing in two different rows longitudinally and laterally offset with respect to each other. Significantly more transceivers may also be incorporated, such as, for example, 5 to 10 transceivers. In the case of a preferred embodiment, on the other hand, exactly three, exactly four or exactly five transceivers are arranged in the probe housing, the first and third transceivers are arranged next to each other in a first row, and the second transceiver is arranged in a first row. It is provided that the first and second transceivers are arranged to be symmetrically offset with a gap in the second row. If four transceivers are provided, the fourth transceiver is preferably arranged in the second row at a lateral distance from the second transceiver. A possible fifth transceiver may also be arranged in the first row.

When optimizing the number, dimensions and distribution of transceivers, on the one hand, in the case of a defect of a given size, the larger both the individual signal amplitudes of the receiver, the smaller the effective check width, or the larger the ratio between the defect size and the effective check width. should be considered To this extent, a larger number of transceivers, such as 6 to 10 or more, may be advantageous for large signal amplitudes. On the other hand, as the number of transceivers increases, the technical effort required to positionally accurately accommodate these transceivers and corresponding test electronics and evaluation also increases. In contrast, if only the two transceivers are placed back and forth offset from each other in two rows, the individual effective check width may have to be relatively large, as a result of which the signal amplitude is probably not large enough, especially for small defects. Therefore, at the present time, a number of exactly 3 or exactly 4 or exactly 5 transceivers in the probe is considered advantageous.

Transceivers disposed in different rows may all have the same orientation of their transmitter and receiver elements with respect to the longitudinal or inspection direction. Thus, for example, both transmitter parts may radiate in the same direction (in each case as viewed in the inspection direction), either obliquely forward or obliquely backward. In contrast, in some embodiments, the transceiver units of the probe are arranged distributedly in the first row and the second row, and the transmitter elements of the transceive units arranged in different rows face each other in the middle region of the probe (considered in the longitudinal direction) It is arranged to be viewed and, due to the roof shape, it is provided that the plates of the transmitter element are arranged obliquely relative to each other such that the transmitter elements radiate respectively from the inside to the outside in opposite oblique directions due to the roof angle. As a result, better acoustic separation of the transceivers placed in different rows can be achieved purely on the basis of the main radiation directions pointing away from each other. The probe housing can be designed such that mutually offset transceivers have respective adapted sub-portions of the probe housing into which they can fit. This can lead to complex external contours of the probe housing with corners and internal angles. Preferably, the probe housing has a rectangular cross-sectional shape. In particular, the probe housing may be sized and designed to correspond to a probe housing of a conventional multiple oscillator separated multiple times in cross-sectional shape and size. It can be easily changed during the conversion process at the time of exchange.

It will also be possible to electrically connect some or all receiver elements and connect them to a common receiver terminal element. Preferably, however, each of the receiver elements is provided to be electrically connected to a separate receiver terminal element of the probe. As a result, the exact assignment of the position of the individual combined signal or to a narrow inspection track in the transverse direction is possible, so that the locability of the defect in the transverse direction can be further improved.

The transmitter terminal element and the receiver terminal element may also be housed in a common connector housing, so that the electrical connection of the probe after installation in the probe holder is very easy and, moreover, its use in existing inspection systems is probably due to cabling. will not require any adaptation of.

Preferably, there is a separating wall (sound baffle) between the transmitter element and the receiver element for sound separation, for example of an ultrasonically-damping material, such as cork, foam or the like. In some embodiments, it is alternatively or additionally provided for this purpose that at least one separating wall of ultrasonic-damping material, for example cork, is arranged between adjacent transceivers in one row. Consequently, interference in the transverse direction can be reduced or avoided. If two or more transceivers are arranged next to each other in a row, these transceivers may have a common separating wall, which separating wall acoustically separates the transmitter and receiver elements of the transceiver from each other. In this way, the manufacturing effort required for acoustic isolation can be reduced.

For acoustic optimization of the probe, a damping body may be assigned to each transceiver, and the damping body is located opposite from the side of the probe that is in acoustic conductive contact with the surface of the test object. Although each transceiver may be provided with its own damping body, the probe housing preferably has a single damping body, which acts as a damping body for both transceivers. One effect of this configuration is that manufacturing is simplified.

The present invention also relates to an ultrasound inspection system for non-destructive inspection of an inspection object during relative movement of the inspection object with respect to the probe along an inspection direction, said ultrasound inspection system having at least one of the probes according to the invention. This ultrasonic inspection system may in particular be an ultrasonic metal plate inspection system.

Further advantages and aspects of the invention emerge from the claims and from the following description of a preferred exemplary embodiment of the invention, which description will be given hereinafter on the basis of the drawings.
1 shows an ultrasound probe according to an exemplary embodiment of the present invention in a plan view from the active side of the probe.
Fig. 2 shows a cross-sectional view of the probe from Fig. 1 in a state of being installed in a probe holder;
3 shows a schematic plan view of an embodiment with another arrangement of an acoustic damping separating wall;
4 shows a schematic plan view of another embodiment with another arrangement of an acoustic damping separating wall;
Fig. 5 shows a cross-sectional view of a variant of the embodiment shown in Fig. 2 with a different sequence of transmitter and receiver elements;

1 schematically shows a probe 100 according to an exemplary embodiment of the present invention, in a plan view from the active side of the probe, ie from the side which brings the probe near the surface of the inspection object to be inspected. 2 shows a cross-sectional view. This probe is intended for use in a fully automatic ultrasonic metal plate inspection system, in which multiple nominally identical probes are used. The probe preferably operates at a nominal frequency of approximately 4 or 5 MHz, in this case three sounding and three acoustic acoustic transducers combined to form a transmit/receive probe (transceiver probe).

The probe has a preferably milled metal probe housing 110 having a substantially rectangular cross-sectional shape in the drawing plane of FIG. 1 , the width in the transverse direction Q being the length in the longitudinal direction L bigger than twice In the case of this example, the width in the transverse direction is approximately 65 mm, while the length measured perpendicular to it is approximately 24 mm to 25 mm. On the active surface 120 side, the probe housing is open (compare FIG. 2 ). On the back layer opposite from the active surface, the probe housing is closed away from the passage for the electrical lines.

As schematic FIG. 2 shows, during setup of the inspection system, the probe 100 is inserted into a probe holder 200 which, together with a plurality of nominally identical probe holders, is on the surface of the inspection system. fastened on the inspection carriage. The probe holder 200 is on its lower surface facing the inspection object 290, so-called in the form of a solid plate of a wear-resistant material such as high grade steel and/or hardened steel material with light metal inclusions, for example. It has a wear sole (wear sole) 210 . For inspection, the probe holder is infeed in the direction of the inspection object 290 so that the wear sole contacts the surface 292 of the inspection object, which surface as the inspection object moves relative to the probe holder in the inspection direction 295 slide on top The probe is installed in the probe holder so that, in this case, the longitudinal direction L of the probe runs as parallel to the inspection direction 295 as possible. The height direction H, running at right angles to the longitudinal and transverse directions, then extends upward as vertically as possible from the surface of the inspection object. Normal inspection speeds during inspection operations after infeeding of both probe holders are generally between, for example, 0.5 m/s and 1 m/s.

The wear sole 210 has a rectangular cutout or rectangular clearance or opening 215 , the rectangular cutout or rectangular clearance or opening 215 passes inward from the contact surface 212 , and the probe 100 passes through the probe holder. It is sized in the longitudinal (L) and transverse (Q) directions so that it can be inserted into play with less lateral play from the inside of the . At the rear end of the probe, ie on the side facing away from the active surface 120 , there is a carrier plate 220 , which serves for fastening and vertical alignment of the probe in the probe holder 200 . When the probe is installed in the probe holder, the probe has a so-called constant thickness possible over the width of the probe, between the plane defined by the planar active surface 210 of the probe and the contact surface 212 of the wear sole 210 . It is positioned so that a bonding gap SP remains. The thickness (D) is often on the order of the order of 0.25 mm to 0.35 mm. During the inspection operation, this gap is filled with a bonding liquid, typically water. Especially in the longitudinal direction, the setting of the mating gap, which is not exactly wedge-shaped, is a key prerequisite for reliable ultrasound examination.

The probe 100 is designed to have a large sensitivity that is relatively uniform without any major local drop in sensitivity over its entire effective probe test width (PKPB). For this purpose, in the case of this example, three nominally identical transceivers are arranged in the inner housing space, which spaces are probe housings, specifically the first transceiver 150-1 and the second transceiver 150-2. ) and surrounded by the third transceiver 150-3. Each transceiver comprises a single transmitter element (T1, T2 or T3) and a single receiver element (R1, R2, R3) assigned to the transmitter element. The transmitter element and the receiver element have in each case a thin rectangular platelet of piezoelectric material, which in the case of the transmitter element acts as a sounding ultrasonic transducer and in the case of the receiver element as an acoustic ultrasonic transducer. do. There are contacts on the anterior side and the posterior side, but they are not shown. The rectangular plates extend parallel to each other in the transverse direction Q and are arranged inclined relative to each other so that a roof shape formed mirror-symmetrically with respect to the plane of separation is obtained, for example, with a roof angle of eg 6°. (Fig. 2). In the separation plane (the plane of symmetry of the roof arrangement), a separation wall 152-1 of ultrasonic-damping material runs between the ultrasonic transducers. The separating wall, preferably made of cork material, serves as an acoustic separation of the transmitter and receiver elements of the transceiver, so that sound transmission can only occur indirectly through the material of the test object to which it is coupled during the test. The separation wall will also serve as electrical isolation of the ultrasonic transducer on the transmit side and the receive side.

The order of the transmitter and receiver elements of the transceiver in the inspection direction may also be reversed from the illustrated order. An example will be described in connection with FIG. 5 .

Installed above the transceiver element in the interior of the probe housing 110 closed on the rear side is a single damping body 260, which serves as a rear sound damping for both the transceiver and the transceiver. The free volume of the interior space of the housing between the transmitter element, the receiver element and the separating wall is filled with a potting compound of plastic up to the plane of the active surface 120 so that the electrically operative element of the probe is sealed in a watertight manner.

Each of the transceivers has a valid check width, PB1, etc., measured in the transverse direction, which is slightly (approximately 10% to 20%) than the physical extent of the transmitter element T1 and the receiver element R1 in the transverse direction. %) small. To illustrate the effective inspection width of the first transceiver 150 - 1 , FIG. 1 shows a typical signal amplitude profile over the element length measured in the transverse direction Q, for a reference defect FBH-2. Curve E1 is shown. This signal amplitude is a measure of sensitivity. This sensitivity profile is characterized by a shallow local drop in sensitivity in the middle of the element, two local maxima (M1, M2) closer to the outer edge of the element, and also a sharp drop in sensitivity in the immediate vicinity of the end in the transverse direction. of a relatively high achievable signal amplitude with a relatively wide plateau symmetrical about the middle of the transceiver. The effective check width PB1 may be defined, for example, to refer to a region where the signal amplitude is lower, for example, by up to 4 dB below a local maximum. The other transceivers have corresponding valid check widths PB2 and PB3. The effective inspection width may be, for example, 20 mm or more. During relative movement of the test object 290 with respect to the probe along the inspection direction 295, each of the transceivers scans an inspection track of a width (in the transverse direction) corresponding to the effective inspection width of each transceiver.

The transceiver is arranged relative to each other such that its effective inspection width and the three inspection tracks scanned by the transceiver partially overlap in the transverse direction, so that scanning can be performed with high sensitivity over the entire probe inspection width. To this end, the transceiver unit is arranged in two straight rows 155-1 and 155-2, these straight rows are arranged before and after each other in the longitudinal direction (L), respectively, proceed in the lateral direction (Q). The first transceiver 152-1 and the third transceiver 152-3 are provided in the first row 155-1 at a mutual distance DQ in the lateral direction Q in this case, so that each transmitter The separation planes between the elements T1 , T3 and the receiver elements R1 , R3 coincide with each other or are in line with one another. Between two transceivers in the same row, the distance DQ, measured in the transverse direction Q, is between 40% and 60% of the respective width of the transceivers in this direction.

The second transceiver 150 - 2 is arranged in the second row 155 - 2 , that is, offset in the longitudinal direction with respect to the first and third transceivers. The second transceiver is symmetrical to the other transceivers, so that a gap between the transceivers in the first row is completely covered. The second transceiver 152 - 2 extends on both sides in the transverse direction to the extent that, when viewed in the longitudinal direction, the outer portion lies behind the outer portion of the transceivers placed in the first row. This configuration is such that transceivers from different rows (first row, second row) have receiver elements of the transceiver that are offset with respect to each other, and also the inspection tracks scanned by these transceivers are overlapped in regions U1-2 or U2-3) offset relative to each other in the lateral direction Q to overlap, achieving the effect that the transceivers together cover the effective probe test width PKPB without any gaps and without any significant drop in sensitivity. The widths of the overlapping regions U1-2 and U2-3, measured in the lateral direction Q, are approximately 15% to 20% of the effective inspection widths PB1, PB2, PB3 of the individual transceivers. This configuration ensures, on the one hand, that inspection can be carried out with high sensitivity even in the overlapping area of the inspection object, and on the other hand, that the entire effective probe inspection width can be covered with a relatively small number of only three transceivers.

1 , it can be seen that all of the transmitter elements T1 , T2 and T3 of the probe 100 are connected to the common transmitter terminal element AT of this probe. From each receiver element R1 , R2 and R3 separate electrical lines run to separate receiver terminal elements AR1 , AR2 , AR3 . The transmitter terminal elements (AT) and the receiver terminal elements (AR1, AR2 and AR3) are housed in a common connector housing (multi-connector) so that the probe can be conveniently connected to the ultrasonic electronics of the ultrasonic inspection system by connecting to the corresponding sockets. have.

There are several possibilities of acoustic and electrical separation of transmitter and receiver elements. 1 and 2, each transceiver has its own separating wall 152-1 between the transmitter element and the receiver element. The separating walls are not interconnected. In the case of the exemplary embodiment of the probe 300 of FIG. 3 , there is a common separating wall 352 for the two transceivers disposed in the same row (the first row). As a result, manufacturing can be simplified. In the case of the exemplary embodiment of the probe 400 of FIG. 4 , between the transceiver in the first row and the transceiver in the second row, there is a transversely running dividing wall 452 . On the narrow side of the transceiver there is also a further dividing wall running in the longitudinal direction. In particular, the dividing walls are disposed on the mutually facing sides of the transceivers of the first row, so that possible interference in the probe is better suppressed than in the exemplary embodiment without such a dividing wall.

1 to 4, the transmitter elements (T1, T2, etc.) of the different transceivers lie in planes running parallel to each other at an angle to the LQ plane, so that they lie before and after each other in the longitudinal direction (L). All of the transmitter elements in the radiate in the same direction due to their oblique position. The radial direction of the three transmitter elements T1 , T2 and T3 of the embodiment from FIG. 1 will radiate obliquely forward in this direction during movement of the probe in the longitudinal direction L (upward in FIG. 1 ).

In FIG. 5 , a variant of the embodiment shown in FIGS. 1 and 2 is shown in a cross-sectional view similar to FIG. 2 . For reasons of clarity throughout, the same reference numbers are used. The only difference compared to the variant from FIG. 2 is that the transmitter elements T1 and T2 of the transceiver, which lie before and after each other in rows parallel to each other, are arranged at an angle to each other rather than lying in planes parallel to each other. The same configuration also applies correspondingly to the receiver elements R1 and R2. One of the effects achieved by this configuration is that the transmitter elements T1 , T2 of the transceiver directly following each other in the longitudinal direction have a sound-radiating surface and face away from each other and are adjacent to each other in the overlapping area. As a result of the opposite oblique positions, the main radiation directions (double arrows) are oriented such that the transmitter elements transmit ultrasonic waves from the inside out respectively. Therefore, when viewed in the longitudinal direction, the main radial direction has opposite components. Consequently, further improved acoustic separation of the transmitter elements placed in different rows can be achieved, for example compared to the orientation shown in FIG. 1 . Therefore, in the case of a two-row arrangement, the transmitter elements, when viewed in the longitudinal direction, can each be arranged in the middle region of the probe, which, due to its inclined position, transmits the sound to both sides (in the longitudinal direction) due to the angle of the roof. release to the outside

Corresponding modifications are also possible in the case of the exemplary embodiment of FIGS. 3 and 4 . Thus, for example, in the case of a variant derived from FIG. 3 , the arrangement of the transmitter element T2 and the receiver element R2 may be exchanged, such that the transmitter element T2 is a transmitter element of two transceivers in different rows. (T1 and T3) and immediately adjacent. Also in the case of the arrangement from FIG. 4 a corresponding modification may be provided such that the transmitter element T2 is directly adjacent to the separating wall 442 , whereas the receiver element R2 is on the outside, ie of the probe housing. placed nearby

As is known, ultrasound examination is based on sound waves propagating at different speeds in different media. These sound waves are partially reflected at the boundary of different wave impedances. Due to the increasing difference in wave impedance, the reflected component also increases. A change in the acoustic properties at the boundary of the area of the defect or break in the interior of the inspection object to be inspected reflects the sound pulses emitted by the transmitter element and transmits these sound pulses to the receiver element of the probe. Voids (cavities), inclusions, cracks or other separations in the microstructure are considered, for example, as defects (or breaks). In the case of the pulse-echo method, the time elapsed between transmission and reception is measured. A signal may be generated based on the measured time difference. Based on this signal, the location of the break and the size of the defect or break can be determined compared to an equivalent reflector (eg, a flat bottom hole (FBH), groove or transverse bore). In the case of automated inspection systems, information is stored, established with respect to the inspection object and documented either immediately or later in several ways.

Inspection with four separate conventional transmit and receive probes has shown that these probes can have sufficient sensitivity over the entire effective probe inspection width for an equivalent reflector down to the FBH-3 (3 mm diameter flat bottom hole) rating. . However, it has been found that detection of baseline defects with FB-2 or lower is often not possible with sufficient reproducibility. One of the reasons for this sensitivity limit is the area of lower sensitivity in the vicinity between adjacent receiver elements in a row. The new placement of transceivers in probes with overlapping test tracks or effective test widths according to an exemplary embodiment of the present invention is accordingly a criterion of FBH-2 or less (eg, down to FBH-1.2 or FBH-1 or less). Allows defects to be detected with good reproducibility.

Claims (14)

A probe (100) for an ultrasonic inspection system for non-destructive material inspection during relative movement of an inspection object (290) with respect to the probe in an inspection direction (295), the probe (100) comprising:
a probe housing 110 defining a longitudinal direction (L) in the inspection direction and a lateral direction (Q) perpendicular to the inspection direction; and
It includes a plurality of transmitting and receiving units (150-1, 150-2, 150-3),
Each transceiver has a transmitter element (T1, T2, T3) and a separate receiver element (R1, R2, R3) assigned, and defines a valid check width (PB1, PB2, PB3) in the transverse direction (Q). and
during relative movement of the test object with respect to the probe along the test direction, each of the transceivers scans an inspection track on the surface of the test object, the respective transceiver having a width corresponding to the effective inspection width of each transceiver;
the transceivers are disposed in at least two rows (155-1, 155-2) which lie in front of and behind each other in the longitudinal direction (L) and run in the transverse direction (Q);
Transceivers from different rows are such that the receiver elements R1, R2, R3 of the transceivers, which are offset with respect to each other, overlap each other in the overlapping regions U1-2, U2-3, so that the transceivers together are random offset relative to each other in the lateral direction (Q) to cover the effective probe test width (PKPB) without gaps;
All of the transceivers are disposed in the probe housing 110,
all of the transmitter elements (T1, T2, T3) are electrically connected to a common transmitter terminal element (AT) of the probe,
The transmitter elements T1, T2, T3 and the receiver elements R1, R2, R3 have in each case a plate of piezoelectric material, the plates of the transceiver being arranged obliquely relative to each other, in a plane of separation A roof shape is obtained which is formed mirror-symmetrically with respect to the probe. The probe according to claim 1, characterized in that the overlapping regions (U1-2, U2-3) have a width of at least 10% of the effective test width (PB1, PB2, PB3) in the transverse direction. The method according to claim 1 or 2, between the adjacent transceivers (150-1, 150-2) in the row (155-1), the interval (DQ) greater than 30% of the effective check width (PB1, PB2, PB3) of the transceiver. ), characterized in that there is, the probe. delete The method according to claim 1 or 2, wherein exactly three or exactly four transceivers (150-1, 150-2, 150-3) are disposed in the probe housing (110), and the first and third transceivers are first disposed next to each other in a row 155-1, and the second transceiver 150-2 is disposed to be symmetrically offset with respect to the first and third transceivers in a second row 155-2 Characterized by the probe. The method according to claim 1, wherein the transceivers (150-1, 150-2, 150-3) are arranged distributed in the first row (155-1) and the second row (155-2), arranged in different rows The transmitter elements of the transceivers are arranged facing each other in the middle region of the probe, and due to the roof shape, the plates of the transmitter elements each radiate outward in opposite oblique directions during operation due to the roof angle of the transmitter elements. Probes, characterized in that they are arranged obliquely relative to each other so as to The probe according to claim 1 or 2, characterized in that the probe housing (110) has a rectangular cross-sectional shape. The probe according to claim 1 or 2, characterized in that each of the receiver elements (R1, R2, R3) is electrically connected to a separate receiver terminal element (AR1, AR2, AR3) of the probe. The probe according to claim 8, characterized in that the transmitter terminal element (AT) and the receiver terminal elements (AR1, AR2, AR3) are accommodated in a common connector housing. The probe according to claim 1 or 2, characterized in that a single damping body (260) acting as a damping body for both the transmitting and receiving units is disposed in the probe housing (110). The probe according to claim 1 or 2, characterized in that the probe has at least one separation wall of ultrasonic-damping material, the separation wall being arranged between adjacent transceivers in a row. An ultrasonic inspection system for non-destructive inspection of an inspection object during relative movement of the inspection object with respect to a probe in an inspection direction, the ultrasonic inspection system comprising:
An ultrasound examination system having one or more of the probes of claim 1 or 2 . The probe of claim 2 , wherein the width of the overlapping regions in the transverse direction is also in the range of 20% to 30% of the effective inspection width. The probe according to claim 1, characterized in that a separating wall (152-1) of ultrasonic-damping material runs between the plates in the separating plane.

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