ULTRASOUND TESTING DEVICE

Description

[0001] The invention relates to an ultrasonic testing device according to the preamble of claim 1.

[0002] Furthermore, the invention relates to a method for non-destructive testing of a component, in particular a fiber-plastic composite component.

[0003] US 4 393 991 A shows an ultrasonic nozzle according to the preamble of claim 1.

[0004] JP S57142358 U discloses an ultrasonic testing device with an ultrasonic probe and a liquid nozzle. The liquid is supplied radially to the liquid nozzle via a supply line, flows approximately perpendicular to the front of the ultrasonic probe, and exits the nozzle via an outlet. This prior art also includes guide ribs, which, however, extend exclusively along the liquid supply line. These guide ribs end outside the probe and therefore do not extend to the front of the probe. Thus, this prior art only allows for reducing turbulence in the water supply. The flow in front of the probe is not improved.

[0005] US 3,486,700 A and US 2004 / 144867 A1 describe different types of nozzles which would also not be compatible with ultrasonic testing devices as shown in JP S57142358 U.

[0006] As further described in EP 0 119 096 A2, ultrasonic probes are used for the non-destructive testing of materials and components. For example, inhomogeneities and defects within the components can be located. The ultrasonic transducer emits ultrasonic waves, which are transmitted to the component by a liquid jet. The liquid jet is formed by a liquid nozzle attached to the housing of the ultrasonic probe in front of the transducer. Depending on the design, the reflected ultrasonic waves can be received by the same ultrasonic transducer ("pulse echo mode"), or the ultrasonic waves pass through the component and are fed to a receiver transducer via a second liquid jet ("through transmission mode"). The incoming waves are converted into an electrical signal, which is electronically evaluated.This prior art also addresses the problem that the water flow within the ultrasonic probe is subject to various disturbances that can impair the ultrasonic signal. For this reason, EP 0 119 096 A2 proposes equipping the housing of the ultrasonic probe with a plurality of circumferentially spaced channels extending in the flow direction, through which the liquid is guided toward the liquid nozzle. These channels are intended to help achieve a linear and laminar flow of the liquid.

[0007] In practice, however, it has been shown that this approach can at best maintain the laminar nature of the flow in the steady state of the ultrasonic probe. The flow in front of the transducer is barely improved. When testing components with three-dimensional geometries, the ultrasonic probe must also perform complex movements, particularly rotations. In the state of the art, these rotations must be performed very slowly to avoid turbulence and the resulting signal degradation. This problem is exacerbated by the fact that the testing of tight component contours requires short ultrasonic probes, which are particularly susceptible to turbulence caused by rotation. The fluid channels of EP 0 119 096 A2, on the other hand, actually extend the ultrasonic probe.

[0008] GB 1 419 118 A describes an ultrasonic testing device in which a laminar flow is to be improved by parallel tubes extending in the flow direction. The tubes are arranged upstream of a nozzle for the water outlet, as seen in the flow direction. This prior art essentially has the same disadvantages as EP 0 119 096 A2. The tubes increase the length of the ultrasonic probe. Furthermore, the water flow can only be maintained laminarly in a static state.

[0009] In contrast, the object of the present invention is to alleviate or eliminate at least some of the disadvantages of the prior art. The invention preferably aims to enable efficient testing of components with three-dimensional geometries.

[0010] This object is achieved by an ultrasonic testing device having the features of claim 1 and a method according to claim 10. Preferred embodiments of the invention are specified in the dependent claims.

[0011] According to the invention, the liquid nozzle has at least one liquid guide rib which projects inwards from the tapered inner surface of the liquid nozzle into the sound space in front of the ultrasonic test head.

[0012] Thus, at least one liquid guide rib protrudes from the smooth, elevation-free inner surface into the interior of the liquid nozzle. This allows the liquid flow to be kept largely laminar not only in the static state of the ultrasonic testing device, but also during movement of the ultrasonic testing device. This allows movements of the ultrasonic testing device to be carried out at higher speeds than with the prior art without seriously impairing the measurement signal. Advantageously, this can significantly improve the results of component testing and accelerate the testing process. Since the liquid guide rib extends along the inner surface of the liquid nozzle, which converges towards the front, the length of the liquid nozzle, i.e. its axial extent, can be kept short. This enables the testing of narrow and strongly curved components.Thanks to the fluid guide rib, testing can be carried out reliably and precisely, even on complex, three-dimensional component geometries, during the necessary movements and rotations of the fluid nozzle. It is also advantageous if the flow velocity of the fluid, especially water, can be kept essentially constant until the fluid outlet.

[0013] To avoid unwanted reflections of the ultrasonic signal, it is advantageous if the liquid guide rib extends from the tapered inner surface to an edge region at the front of the ultrasonic probe, with a central region at the front of the ultrasonic probe being free of the liquid guide rib. Thus, viewed radially, the liquid guide rib ends in the edge region of the sound chamber in front of the ultrasonic probe and does not extend into the central region of the sound chamber in front of the ultrasonic probe, which extends around the central axis of the liquid nozzle. In contrast, in the prior art according to JP S57142358 U, the rib does not extend into the sound chamber in front of the probe.

[0014] To ensure laminar liquid flow along the inner surface converging in the axial direction towards the liquid outlet, the liquid nozzle has several liquid guide ribs on the tapered inner surface.

[0015] To minimize the impact of the fluid guide ribs on the measurement signal, it is advantageous if the inner longitudinal edges of opposing fluid guide ribs are arranged at a radial distance from each other, so that the fluid nozzle has a central area free of fluid guide ribs. Thus, the fluid guide ribs do not define individual, closed flow channels, but are connected via the open central area.

[0016] If the liquid guide ribs are arranged at regular angular intervals, viewed in the circumferential direction of the inner surface, on the tapered inner surface of the liquid nozzle, the liquid flow can be kept essentially laminar during displacements and rotations in different directions and axes.

[0017] Furthermore, the height of the liquid guide ribs decreases toward the liquid outlet. Thus, the wider the flow cross-section within the inner surface of the liquid nozzle, which tapers toward the liquid outlet, the higher the liquid guide ribs become. This design has proven particularly effective in improving laminar flow without significantly impairing the ultrasonic signal.

[0018] Because the inner longitudinal edges of the fluid guide ribs run essentially parallel to each other, a substantially cylindrical central area is created in which the fluid can flow unhindered. This optimizes the flow conditions and the ultrasonic signal. This design has proven particularly effective in reducing or eliminating side lobes in the sound field.

[0019] In an alternative design, the radial distance between opposing fluid guide ribs decreases in the axial direction toward the fluid outlet. Thus, the fluid guide ribs extend less inward on the ultrasonic probe side. This design can be used in a multi-frequency ultrasonic probe to preserve the side lobes of the sound field.

[0020] In a preferred embodiment, the tapered inner surface of the liquid nozzle adjacent to the liquid outlet is free of liquid guide ribs. Since the flow cross-section near the liquid outlet is comparatively small, the liquid guide ribs can be omitted in this section.

[0021] In order to optimize the flow conditions, the inner surface of the liquid nozzle is, in a preferred embodiment, shaped according to a spline polynomial 3 to 5 . Tapered to a degree. This design has proven particularly advantageous for achieving laminar flow when the fluid nozzle is stationary. Thanks to the fluid guide rib, this laminar fluid flow can be maintained even when the fluid nozzle is shifted or rotated.

[0022] For testing narrow or highly curved areas of a component, it is advantageous if the liquid nozzle has an axial extension of less than 60 mm from the center of the ultrasonic probe to the liquid outlet. In a preferred embodiment, a drive is provided for moving the liquid nozzle, in particular for rotating the liquid nozzle around its longitudinal axis and / or a transverse axis perpendicular thereto.

[0023] In a preferred embodiment, a liquid supply is provided, with which a liquid flow, in particular water, is fed to an annular inlet between a receiving housing and the outside of the liquid nozzle, deflected by a deflection ring, and guided to the liquid inlet of the liquid nozzle. The liquid inlet extends in a ring shape on the rear side of the liquid nozzle. The annular liquid inlet ensures that the inflow of the liquid flow is laminar.

[0024] Preferably, the rear end of the fluid guide rib (as viewed in the direction of fluid flow) is located within the fluid inlet. From the rear end, the fluid guide rib extends forward (as viewed in the direction of fluid flow) into the acoustic chamber in front of the probe.

[0025] In a preferred application, a testing system is provided with a handling element, in particular with a robot arm, to which a tool with an ultrasonic testing device according to one of the embodiments described above is attached.

[0026] In a preferred embodiment, a further ultrasonic testing device is provided with a further ultrasonic probe and a further liquid nozzle for receiving ultrasonic waves passing through the component. The further ultrasonic testing device is preferably designed like the ultrasonic testing device according to one of the embodiments explained above. The ultrasonic probe transmits the ultrasonic waves; the further ultrasonic probe receives the ultrasonic waves on the opposite side of the component. In this embodiment, the ultrasonic probe and the further ultrasonic probe are coupled to one another via the liquid jets, which are applied to opposite sides of the component via the liquid nozzles. This allows for ultrasound scanning of the component.

[0027] Depending on the design, the further ultrasonic testing device can be arranged on a further handling element or, in particular with the aid of a fork element, on the handling element.

[0028] In a further embodiment, the ultrasonic testing device is configured to receive reflected sound waves. Thus, a reflected sound method can be performed. This embodiment can be provided in addition to or as an alternative to through-transmission using the additional ultrasonic testing device.

[0029] To carry out a method according to the invention for non-destructive testing of a component, in particular a fiber-plastic composite component, the following steps are carried out (not necessarily in the specified order): Providing the ultrasonic testing device in one of the embodiments described above, generating ultrasonic waves with the ultrasonic test head, supplying a liquid flow into the liquid nozzle via the liquid inlet, guiding the liquid flow along the inner surface of the liquid nozzle to the liquid outlet, wherein the liquid flow is guided by means of the liquid guide rib.

[0030] Preferably, the method also comprises the step: Providing a further ultrasonic testing device, which is preferably designed like the ultrasonic testing device in one of the above variants; receiving ultrasonic waves passing through the component with a further ultrasonic probe of the further ultrasonic testing device.

[0031] In this design, the ultrasonic waves pass through the component and are fed to the other ultrasonic test head via a second liquid jet ("through transmission mode").

[0032] Alternatively or additionally, the ultrasonic testing device can be used to detect the ultrasonic waves reflected in the component.

[0033] In a preferred embodiment, the method for non-destructive testing of the component further comprises the step of rotating the liquid nozzle, in particular about its own axis, while guiding the liquid flow along the inner surface of the liquid nozzle to the liquid outlet, so that the liquid flow is carried along by the liquid guide rib during the rotational movement.

[0034] The invention is further explained below with reference to a preferred embodiment shown in the drawings.

[0035] Fig. 1 shows a testing system for non-destructive testing of a fiber-reinforced plastic composite component.

[0036] Fig. 2A bis 2C show a changing device of the test system according to Fig. 1 with an interchangeable adapter and a tool mounted thereon for non-destructive testing of the fiber-plastic composite component, wherein the tool has an ultrasonic testing device according to the invention.

[0037] Fig. 3, Fig. 4 and Fig. 5 show a tool head of the tool according to Fig. 2A bis Fig. 2C , opposite which is a corresponding ultrasound probe with a receiver transducer.

[0038] Fig. 1 shows a testing system 27 for non-destructive testing of a fiber-reinforced plastic composite component. The testing system comprises a changing device 26, an adapter plate 25, and a handling element 28, which in the illustrated embodiment is designed as a robot arm. The adapter plate 25 is mounted on one side of the handling element 28. The changing device 26 is detachably connected to the other side of the adapter plate 25.

[0039] As from Fig. 1 as well as in detail Fig. 2A bis 2C As can be seen, the changing device 26 has a change adapter 5, to which a (in Fig. 1 not visible) tool 30 for non-destructive testing of the fiber-plastic composite component is mounted. The tool 30 has a cylindrical motor housing 31 coaxially adjacent to the interchangeable adapter 5, which is connected to the interchangeable adapter 5 in a rotationally fixed and detachable manner. A motor, in particular a servomotor, is arranged in the motor housing 31. On one side of the motor housing 31, which is opposite the interchangeable adapter 5 when the tool 30 is mounted, the tool 30 has a cylindrical gear housing 32, which is arranged coaxially to the cylindrical motor housing 31. A gear is arranged in the gear housing 32, which is connected to the servomotor and converts the torques and / or speeds generated by the servomotor. On a side 34 of the gear housing 32 opposite the motor housing 31, a tool head 35 is arranged, which is rotatably arranged about a transverse axis 36A on a holder 36 fastened to the gear housing 32.With the help of the servo motor, the tool head 35 can be rotated relative to the holder 36 about the transverse axis 36A (see arrow 36B in . Fig. 2A ). In the embodiment shown, the power of the motor is transmitted to the tool head 35 via a toothed belt in a toothed belt housing 31A.

[0040] The tool head 35 has an ultrasonic probe 37 and a liquid nozzle 38 with which a water jet is directed onto the component.

[0041] The tool 30 can be rotated about its longitudinal axis 30A with a further drive, for example the handling element 28, as shown in Fig. 2A is illustrated by an arrow 30B. Thus, the liquid nozzle 38 can be rotated about its longitudinal or central axis 46 when the transverse axis 36A is set to 0°, so that the longitudinal axis 46 of the liquid nozzle 38 runs parallel to the longitudinal axis 30A of the tool 30. The rotations about the longitudinal axis 30A and the transverse axis 36A can also be performed simultaneously.

[0042] Fig. 3 bis 5 show an inventive embodiment of the tool head 35, which in the illustrated embodiment has a receiving housing 40 on which the ultrasonic test head 37 and the liquid nozzle 38 are mounted. Also visible in the drawing is an ultrasonic probe corresponding to the tool head 35 with a receiver transducer 49, which receives ultrasonic waves passing through the component (not shown). The incoming waves are converted into an electrical signal, which is electronically evaluated.

[0043] The tool head 35 has a liquid supply 41 for supplying liquid via the bearing of the receiving housing 40. The water supply 41 supplies a liquid flow, in particular water, to an annular inlet between the receiving housing 40 and the outside of the liquid nozzle 38, deflects it with a deflection ring, and guides it to a liquid inlet 42 of the liquid nozzle 38. The liquid inlet 42 extends in a ring shape on the rear side of the liquid nozzle 38. The annular liquid inlet 42 ensures a laminar flow of the liquid flow. At the front end, on the side facing away from the ultrasonic test head or transducer 37, the liquid nozzle 38 has a liquid outlet 43, which is used to direct the liquid flow onto the component during non-destructive ultrasonic testing.

[0044] The liquid flow within the liquid nozzle 38 is in Fig. 5 illustrated by a line 44.

[0045] As from Fig. 5 As can be seen, the flow space within the liquid nozzle 38, also referred to as a spray nozzle or "squirter nozzle," is defined by a smooth inner surface 45, which converges continuously from the liquid inlet 42 to the liquid outlet 43. In the embodiment shown, the inner surface 45 of the liquid nozzle 38 is shaped according to a spline polynomial. 3. The inner surface 45 is curved to a degree of 5. This reduces the flow cross-section of the liquid flow within the liquid nozzle 38 in the direction of the liquid flow. The inner surface 45 is rotationally symmetrical with respect to a central axis 46 of the liquid nozzle 38. Directional references such as "axial" and "radial" refer to the central axis 46 of the liquid nozzle 38.

[0046] As from Fig. 5 As can also be seen, the liquid nozzle 38 has a plurality of liquid guide ribs or projections 47, which protrude radially inward from the inner surface 45 of the liquid nozzle 38 toward the central axis 46 and extend in the axial direction. The inner longitudinal edges 48 of the liquid guide ribs 47 end at an outer edge region of the flow space in front of the ultrasonic probe 37, as seen in the radial direction. Thus, the central region around the central axis 46 is free of liquid guide ribs 47, so that the ultrasonic signal can propagate freely in the central region and disruptive reflections are prevented. The liquid guide ribs 47 are arranged at regular angular intervals in the circumferential direction on the inner surface 45 of the liquid nozzle 38. At least four, preferably at least six, particularly preferably at least eight, in particular at least ten liquid guide ribs 47 can be provided.

[0047] As from Fig. 5 furthermore, the height of the liquid guide ribs 47, ie . Their radial extension tapers off in the axial direction toward the liquid outlet 43, so that the inner longitudinal edges 48 of the liquid guide ribs 47 run essentially parallel to one another. The liquid guide ribs 47 terminate in front of the liquid outlet 43, so that the section adjacent to the liquid outlet 43 is free of liquid guide ribs 47.

Claims

1. Ultrasonic testing device for non-destructively testing a component, in particular a fibre-reinforced plastic component, having: an ultrasonic testing head (37), a liquid nozzle (38) with a liquid inlet (42), a liquid outlet (43), and an inner surface (45) which tapers towards the liquid outlet (43), wherein the liquid nozzle (38) has at least one liquid-guiding rib (47) which protrudes inwards from the tapering inner surface (45) of the liquid nozzle (38) into a sound chamber in front of the ultrasonic probe (37), the liquid nozzle (38) having a plurality of liquid guide ribs (47) on the tapering inner surface (45), characterised in that a height of the liquid-guiding ribs (47) decreases in the direction towards the liquid outlet (43), wherein inner longitudinal edges (48) of the liquid-guiding ribs (47) extend substantially parallel to each other.

2. Ultrasonic testing device according to claim 1, characterised in that the liquid-guiding rib (47) extends from the tapering inner surface (45) into an edge region on the front of the ultrasonic testing head (37), wherein a central region on the front of the ultrasonic testing head (37) is free of the liquid-guiding rib (47).

3. Ultrasonic testing device according to claims 1 or 2, characterised in that the inner longitudinal edges (48) of the liquid-guiding ribs (47) are arranged at a distance from one another, so that the liquid nozzle (38) has a central region free of liquid-guiding ribs (47).

4. Ultrasonic testing device according to claims 1 to 3, characterised in that the liquid-guiding ribs (47) are arranged at regular angular intervals in the circumferential direction on the tapering inner surface (45) of the liquid nozzle (38).

5. Ultrasonic testing device according to one of claims 1 to 4, characterised in that the tapering inner surface (45) of the liquid nozzle (38) adjacent to the liquid outlet (43) is free of liquid-guiding ribs (47).

6. Ultrasonic testing device according to any one of claims 1 to 5, ccharacterised in that the inner surface (45) of the liquid nozzle (38) is tapered according to a spline polynomial of degree 3 to 5.

7. Ultrasonic testing device according to one of claims 1 to 6, characterised in that the liquid nozzle (38) has an axial extent of less than 60 mm from the centre of the ultrasonic testing device (37) to the liquid outlet (43).

8. Ultrasonic testing device according to one of claims 1 to 7, characterised in that a drive is provided to move the liquid nozzle (38), in particular to rotate the liquid nozzle (38) about its longitudinal axis and / or a transverse axis running perpendicular thereto.

9. Testing system with a manipulation element (28), in particular with a robot arm, on which a tool (30) with an ultrasonic testing device according to one of claims 1 to 8 is arranged.

10. Method for non-destructive testing of a component, in particular of a fibre-reinforced plastic component, comprising the steps of: Use of an ultrasonic testing device according to one of claims 1 to 8 for carrying out the following method steps: generating ultrasonic waves using the ultrasonic testing head (37), supplying a liquid flow into the liquid nozzle (38) via the liquid inlet, conducting the liquid flow along the inner surface (45) of the liquid nozzle to the liquid outlet, wherein the liquid flow is guided with the aid of the liquid-guiding rib (47).

11. Method according to claim 10, characterised by: rotating the liquid nozzle (38), in particular about its own axis, while the liquid flow is conducted along the inner surface (45) of the liquid nozzle (38) to the liquid outlet (43), so that the liquid flow is carried over the liquid-guiding rib (47) during the rotary movement.