EP1097374A2

EP1097374A2 - Method and devices for detecting a crack in a railway wheel

Info

Publication number: EP1097374A2
Application number: EP99948656A
Authority: EP
Inventors: Eberhard Fischer; Rainer Meier; Eduard Schulz; Hermann Wüstenberg
Original assignee: Siemens AG
Current assignee: Intelligendt Systems & Services & Co GmbH
Priority date: 1998-07-23
Filing date: 1999-07-16
Publication date: 2001-05-09
Also published as: WO2000005576A2; WO2000005576A3

Abstract

The invention relates to a method for detecting a crack (9) in a railway wheel (1), according to which by means of a first transmitting ultrasonic transducer (31) a first ultrasonic wave (41) is transmitted substantially tangentially to the wheel circumference through a face (27) of the railway wheel (1), at an angle to the face (27). The transmitted ultrasonic wave (41) is received at the level of said face (27). A first angle of acoustic irradiation ( alpha 1) and a first angle of reception ( beta 1) are selected such that the incoming ultrasonic wave (41) can be received if it is reflected by the opposite face (43) and deflected backwards at the crack (9). The invention also relates to devices which are especially suited for carrying out said method. Such a device notably comprises a test bogie (74) which is positioned next to or underneath a railway vehicle (70) moving at low speed and can be displaced in the direction of travel (78) of said vehicle. A probe (29A, 29B) can be fixed to said test bogie and placed onto the face (27) situated on the outside or inside in relation to the railway vehicle (70).

Description

description

Method and devices for detecting a crack in a railway wheel

The invention lies in the field of safety technology for rail-bound traffic, in particular for railways.

The invention relates to a method for detecting a crack in a railroad wheel, in particular for detecting a crack originating from the tread. The invention also relates to a device for carrying out the method and devices for detecting a crack in a railway wheel, in particular for detecting a crack originating from the tread.

The railway wheels of railway trains must be subjected to non-destructive testing for defects, in particular cracks or breakouts, at certain intervals. In particular, cracks must be detected that emanate from an outer circumferential surface, in particular the tread, or from an inner circumferential surface, in particular in the vicinity of the inner circumference of a wheel rim or a tire. The cracks can arise, among other things, from material fatigue, thermal stress as a result of the braking processes and deformation processes as a result of the pressure load. In order to rule out wheel breakage and any consequential fatal damage, the periodic inspection must be carried out at short intervals, e.g. every two to three days, required. The non-destructive testing must be particularly quick, i.e. for an entire train in about an hour.

Railway wheels come in two completely different constructions, namely as solid wheels and as wheels that consist of one

Wheel body and a forged wheel tire placed thereon are assembled. In the case of a wheel body and a A wheel tire made up of a railway tire is subject to particularly high stress.

From German patent DE 37 15 914 C2 and from a technical article entitled "Ultrasonic testing for vertically oriented cracks by using the wave conversion (tandem replacement test) * by Wolfgang Gebhardt and Friedhelm Walte in the journal Materialprüfung 30 (1988) 3, page 73ff a method known as a wave conversion technique or LLT technique for detecting a crack is known.

From the book “Material testing with ultrasound * by Joseph Krautkrämer and Herbert Krautkrämer, published by Springer Verlag, Berlin (1986), 5th edition, on page llOff a test method known as tandem technology for the detection of a crack in a test object is known. Transverse waves radiated at an angle with spatially separated transmitter and receiver probes are used.

Tandem technology and wave conversion technology have so far been used exclusively for the detection of cracks that are located far below a surface and do not reach the surface.

Tandem technology and wave conversion technology have so far been carried out in such a way that the ultrasound wave is radiated into the object to be tested through a surface which is largely perpendicular to the direction of growth of an expected crack.

A method for detecting near-surface defects is known from German published application 28 02 278. A longitudinal wave that creeps along the surface, a so-called creeping wave, is used here.

At the Internet address http: //www.ndt. net / article / report / df97 / hintze / hintze d.htm a technical article by H. Hintze of Deutsche Bahn AG was published on 10.06.1998 at 10.13 a.m., which describes a method for ultrasonic testing of railway wheels using surface waves, so-called Rayleigh waves. An ultrasonic surface wave is generated in the wheel material with an electrodynamic transducer based on permanent magnets (EMUS, which stands for electromagnetic ultrasonic transducer). The surface wave is coupled in through the tread and, starting from the transducer, propagates on both sides along the tread of the wheel. After a complete revolution around the wheel, the Rayleigh wave is received again by another electrodynamic converter. With this test technique, only the area around the running surface of the railroad wheel can be inspected, but not an area around an inner surface of the railroad wheel. Another disadvantage of this technique is that the depth of penetration of the Rayleigh wave is small (magnitude of the wavelength, a few millimeters), so that cracks with only a small depth cannot be distinguished from those with a large depth. In addition, it is not possible to determine the depth of cracks, especially on the outer surface (eg running surface). Another serious disadvantage of this test technique lies in the fact that the wear on the wheel tread has a very large influence on the spreading capacity of the Rayleigh wave. The result of this is that this test technique works very well with new bikes, with older bikes, in particular with a mileage of several 10,000 km, i.e. especially with railway bikes where cracks are increasingly to be expected, but are no longer meaningful and therefore fail .

It is also known from the technical article published at the Internet address mentioned that the tread of railroad wheels, especially the railroad wheels of high-speed trains, have an inner and an outer wear zone with respect to the direction of travel of the train. The two Wear zones extend essentially around the entire outer circumference of the railway wheel. They are spaced apart from each other in a direction parallel to the axis of rotation of the railway wheel. For example, the outer wear zone (zone 1) is 30 to 60 mm and the inner wear zone (zone 2) is 80 to 90 mm from the outer end face of the railroad wheel. The inner wear zone is in particular narrower than the outer one.

In the two wear zones, the railway wheels are subject to particularly high loads, so that cracks tend to occur in these wear zones after prolonged operation. The cracks appear predominantly transversely (vertically) on the surface and, to a lesser extent, obliquely with respect to the running direction of the tread at the respective crack location.

Under the Internet address http://www.ndt.net/article/0698/salzb/salzb.htm, a report on a lecture was given on June 10, 1998 at 10:10 a.m. at the annual conference of the German Society for Non-Destructive Materials Testing in Lindau on 13 until May 15, 1996, held by H.-J. Salzburger and H. Hintze, published. This conference report describes an impulse-echo test method for the detection of a crack in a railroad wheel, in which linear polarized transverse waves are radiated from one end of the railroad wheel perpendicular to the end. This test method uses sound attenuation from waves polarized across the crack. Polarized ultrasound waves must therefore be generated, for which - as in the aforementioned test method - electromagnetic ultrasound transducers (EMUS) are necessary. These so-called EMUS transducers do not function sufficiently reliably at the current state of the art for crack testing on railway wheels. The invention is therefore based on the object of specifying both a method and devices with which the detection of a crack in a railroad wheel is reliable and also possible with a worn tread surface.

The object relating to a method is achieved according to the invention in that, with the aid of a first transmission ultrasound transducer, a first ultrasound wave is inclined essentially tangentially to the wheel circumference, with respect to an end face of the railroad wheel and is radiated through the end face with a first angle of incidence, and from a first reception ultrasound transducer arranged on the end face is received with a first reception angle, the first insonification angle and the first reception angle being selected such that the first ultrasound wave can be received if a reflection on the opposite end face and a rearward deflection on Crack occurred.

Here, the invention is based, inter alia, on the consideration of radiating the ultrasound wave away from what has hitherto been customary into the object to be tested through a surface which extends largely parallel to the growth direction of an expected crack.

The angle of incidence and the angle of reception are measured here and below with reference to the perpendicular, which e.g. stands vertically on the face.

(Substantially) tangential radiation is understood to mean that the component of the insonification direction projected into a plane perpendicular to the axis of rotation is oriented tangentially. The direction of irradiation (direction of irradiation) - as with the further developments of the method - can deviate from a tangent to the wheel circumference, for example by up to +/- 20 ° or by up to +/- 10 °. The backward deflection occurs particularly with respect to a direction of incidence on the crack.

Since in the method according to the invention an ultrasonic wave is radiated through the end face of the railroad wheel, the testing of the railroad wheel is advantageously not affected by a worn tread. At most, the tread is streaked. In addition, the end face serving as a coupling surface is easily accessible.

The method enables a particularly reliable detection of a crack oriented parallel to the axis of rotation of the railway wheel. It is particularly advantageous that such a crack can be found that is very far from the surface and / or does not even reach it.

According to a preferred embodiment, the first insonification angle and the first reception angle are selected in such a way that the first ultrasound wave can be received if the backward deflection occurs on a crack oriented parallel to the axis of rotation of the railway wheel as a result of a wave conversion (wave conversion method).

In particular, the first ultrasonic wave with longitudinal polarization is radiated in at the opposite one

The end face is reflected with longitudinal polarization and, after conversion at the crack into a transversely polarized wave, is radiated back to the end face (LLT process as a special case of the wave conversion process).

The first transmit ultrasound transducer and the first receive ultrasound transducer are preferably designed as group emitters and thus offer the possibility of varying their angle of incidence or reception angle.

The first transmit ultrasound transducer and the first receive ultrasound transducer are then preferably identical, ie it there is only one ultrasonic transducer for both functions.

For example, the first insonification angle and the first reception angle are varied in order to detect a crack lying underneath the end face.

According to another preferred embodiment, the first insonification angle and the first reception angle are selected such that the first ultrasound wave can be received if the backward deflection occurs at a crack oriented parallel to the axis of rotation of the railroad wheel by reflection with a matching angle of incidence and angle of incidence (tandem) Procedure).

In the last-mentioned embodiment, either at least one additional receiving ultrasound transducer assigned to the first transmitting ultrasound transducer or at least one further transmitting ultrasound transducer assigned to the first receiving ultrasound transducer is preferably used for the detection of an unknown crack deep below the end face.

With regard to the above-mentioned configurations, the invention makes use of the further knowledge that tandem technology and wave conversion technology can be used with particular advantage for testing a railway wheel under essentially tangential radiation from the front side, because cracks on a railway wheel are not only on the surface (tread ) are oriented perpendicular to the running direction of the tread at the respective crack location, but in most cases maintain this orientation also below the surface (ie in the volume area). In other words, the crack surfaces usually run in the radial direction from an outer area into the interior of the railway wheel. When using the tandem or wave conversion method, as a departure from the usual, cracks are also detected which originate from the surface, namely from the tread. The testing of such cracks is finally made possible only by the fact that, as previously explained, “from the side ^w is irradiated in a previously unknown manner.

With the two embodiments of the method according to the invention, cracks oriented parallel to the axis of rotation of the railway wheel, in particular essentially perpendicular to the running direction of the tread, can consequently be detected particularly reliably.

When testing a railway wheel, the tandem method has the additional advantage that the transverse polarization used runs parallel to a tangential plane on the tread and is consequently only very slightly influenced by the disintegration zone that occurs just below the tread after prolonged operation of the railway wheel. Otherwise the breakdown zone would lead to undesired disturbances in the wave propagation.

The same applies to that part of the wave propagation in the wave conversion process that takes place with transverse polarization.

According to a preferred development of the method, a second ultrasonic wave is substantially tangential to the wheel circumference, inclined with respect to the end face of the railway wheel and radiated through the end face at a second angle of incidence, and received at the end face at a second reception angle, the second insonification angle and the second reception angle are selected such that the second ultrasonic wave can be received if, as the only deflection in the railroad wheel, there is a reflection on a crack which is oriented obliquely or perpendicularly with respect to the axis of rotation of the railroad wheel. Such a crack is thus oriented obliquely or parallel with respect to the running direction of the tread of the railroad wheel. Such a crack can be detected particularly reliably with the further developed method, so that the number of detectable crack orientations is advantageously increased in the further development.

A crack oriented parallel, obliquely or vertically with respect to the axis of rotation of the railroad wheel is also to be understood in connection with the invention as such a crack which has the mentioned respective orientation only in a partial area.

The second insonification angle and the second reception angle are preferably chosen to be of the same size, in particular in the range around 45 °.

For example, detection is carried out at the coupling point. In the further development, the method then works in addition to the tandem or wave conversion technology in a pulse-echo mode, with which cracks can also be reliably detected which are located on the opposite end face and / or grow along or from there.

According to another preferred development, a third ultrasound wave is inclined at a coupling point essentially tangential to the wheel circumference, with respect to the end face of the railway wheel, and is irradiated through the end face with a third angle of incidence and at a receiving point different from the coupling point under a third receiving angle on the end face received, the third insonification angle and the third reception angle are selected such that, without a present crack, the third ultrasound wave can be received after reflection on the opposite end face and without further deflection in the railroad wheel, and it becomes with a reception that is without reception in terms of reception - lying crack is weakened, the existence of a crack is inferred (shading technique).

With this development, cracks can be detected alternatively or - with an advantageous increase in redundancy and reliability - in addition to the first-mentioned development. Cracks can be found in any orientation. The third incidence angle is preferably approximately + 45 °, the third reception angle preferably approximately -45 °. The third ultrasonic wave radiates through the railway wheel in particular in a V-shape.

The second and / or third ultrasound wave can, together with the first ultrasound wave, possibly from the same ultrasound transducer, and e.g. are emitted as a partial wave (partial beam) of the first ultrasonic wave.

In another advantageous development of the method, an ultrasonic creeping wave is radiated through the end face essentially tangentially to the wheel circumference and, in the event of a creeping wave echo, the presence of a crack with a small depth dimension with respect to the end face is concluded.

The ultrasonic creep wave is longitudinally polarized and is emitted by an ultrasonic transmitter with a low inclination

Front face, preferably at an insonification angle of 65 ° to 90 °. It will e.g. received by a separate ultrasound receiver.

A first ultrasonic wave is preferably radiated in a largely tangential first direction, and a further first ultrasonic wave is radiated in a second direction that is approximately opposite to the first direction. In the same way, a further second or third ultrasonic wave or a further ultrasonic creep wave can be coupled in.

Due to the radiation in opposite tangential directions, a possible crack point can be sonicated on both sides - For example with convex or concave curvature - can be detected even more reliably.

According to another advantageous development of the method, the railroad wheel is the wheel of a railroad train which is moved at a driving speed, for example at least at times constant, and a test head is moved in the direction of travel and at the driving speed such that the position of the test head with respect to the end face remains unchanged remains. The test head is used to irradiate the first

Ultrasound wave and / or for irradiating the second ultrasound wave and / or for irradiating the third ultrasound wave and / or for irradiating the ultrasound creeping wave.

The driving speed has in particular a value in the range from 1 to 10 km / h, preferably from 1 to 5 km / h.

Further advantageous embodiments of the method according to the invention relate to the location of the ultrasonic wave irradiation for a designed as solid wheel railway wheel so ^¬ as for a composite of a wheel body and a wheel tires mounted railway wheel. These configurations are given in the subclaims.

The object related to an apparatus is achieved according to the invention by an apparatus for carrying out the method according to the invention, with a test head which can be placed on the end face of the railway wheel, on which the first transmit ultrasound transducer and the first receive ultrasound transducer and

- Optionally at least one ultrasonic transducer for a second ultrasonic wave and

- Optionally at least one ultrasonic transducer for a third ultrasonic wave and / or

- An ultrasonic transducer for an ultrasonic creeping wave is optionally arranged. According to the invention, the device-related object is also achieved by such a device for carrying out the method, which has a combination test head which can be placed on the end face of the railway wheel, on the ultrasonic transducer for irradiating and receiving the first ultrasonic wave and the further first ultrasonic wave, and

- Optional ultrasonic transducer for irradiating and receiving a second ultrasonic wave and a further second ultrasonic wave as well

- Optional ultrasonic transducer for irradiating and receiving a third ultrasonic wave and a further third ultrasonic wave as well

- Optional ultrasonic transducers for irradiating and receiving an ultrasonic tracking wave and another ultrasonic tracking wave are arranged.

Further advantageous embodiments of the devices according to the invention are mentioned in the subclaims.

Particularly advantageous is an embodiment with a test car arranged to the side of or below the railroad train and movable in the direction of travel, to which the test head or, if applicable, the combination test head can be attached. As a result, it is advantageously possible to carry out the ultrasound test on the railroad wheel while the railroad train traveling with the railroad wheel is traveling through a maintenance hall, etc., and is possibly also being checked or cleaned in some other way.

For example, the test head or the combination test head can be placed from the test car on the inside of the railroad wheel on the inside of the railroad train. The inside end face is particularly easily accessible, for example, from the test car arranged under the train, and offers a larger contact area for ultrasound probes than the outside end face. When checking from below, the inner end faces of railway wheels opposite in relation to the direction of travel are very easily accessible and can be checked at the same time.

For an accelerated test, the test car can have, for example, several test heads or combination test heads for the simultaneous testing of several railroad wheels of a bogie of the railroad train.

The test car can preferably be driven by the moving train. For example, an arm is provided with the aid of which kinetic energy can be transferred from the train to the test vehicle. As a result, the train and the test car are easily synchronized.

Further devices for solving the above object are described in three independent claims.

Several exemplary embodiments of a device according to the invention are shown schematically and in a highly simplified manner in FIGS. 1 to 15. They also serve to illustrate the implementation of a method according to the invention. Show it:

1 shows a railway wheel, shown in a highly simplified manner as a simple disk, in which differently oriented cracks are drawn,

2 shows a plan view of the tread of the railway wheel of FIG. 1,

3 shows a first exemplary embodiment of a device according to the invention in a plan view of an end face of a railway wheel (full wheel),

4 shows a cross section through the railway wheel of FIG. 3 along the line IV-IV, A second embodiment of a device according to the invention in a plan view of an end face of a railway wheel (full wheel),

5 shows a cross section through the railway wheel of FIG. 5 along the line VI-VI,

4 shows a cross section through the railway wheel of FIG. 3 or 5 along the line VII-VII,

A third embodiment of a device according to the invention for testing a wheel tire of a railway wheel in a plan view of the front side of the railway wheel,

a vertical section through the wheel tire of the figure

4 shows a horizontal section through the wheel tire of FIG. 8,

A fourth embodiment of a device according to the invention for testing a wheel tire of a railway wheel in a plan view of the front side of the railway wheel,

3 shows a vertical section through the wheel tire of FIG. 11,

10 shows a horizontal section through the wheel tire of FIG. 11,

a fifth embodiment of a device according to the invention and

a sixth embodiment of a device according to the invention. FIG. 1 shows a railway wheel 1 symbolized as a simple disk with a tread 2, which can be rotated about an axis of rotation 3. When rotating along the direction of rotation indicated by arrows 5, the railway wheel 1 moves in a direction of travel 7 (translational movement).

A total of three differently oriented cracks 9, 11, 13 are shown on the railway wheel 1. The first crack 9 appears on the tread 2 perpendicular (transverse) to the running direction 14 of the railway wheel 1 at the location of the crack 9. Its crack surface is oriented parallel to the axis of rotation 3. The second crack 11 is vertical and the third crack 13 is oriented obliquely with respect to the axis of rotation 3. The cracks 9, 11, 13 run largely radially from the tread 2 into the interior of the railway wheel 1.

Figure 2 shows a plan view of the tread 2 of the railway wheel 1 of Figure 1. It shows how the cracks 9, 11, 13 appear from the outside, viewed from a direction 15 of the tread 2 approximately.

Figure 3, and Figure 4 in a cross-sectional view along the line IV-IV of Figure 3 and Figure 7 in a cross-sectional view along the line VII-VII of Figure 3, show a railway wheel 1 with a tread 2, with a flange 21, with a Wheel rim 22 and with a hub 23. A combination test head 25 is placed on an end face 27 of the railroad wheel 1 largely symmetrically with respect to a radius R of the railroad wheel 1. The combination probe 25 includes an outer probe 29A and an inner probe 29B. The outer test head 29A has a first transmit ultrasound transducer 31, a first receive ultrasound transducer 33 and a further ultrasound transducer 35 assigned to the first transmit ultrasound transducer. The outer test head 29A also has a second received ultrasound transducer 37 and a creeping wave ultrasound transducer 39. The first transmit ultrasound transducer 31 radiates a first ultrasound wave 41 through the end face 27 in the direction of the opposite end face 43 into the railway wheel 1 (FIG. 4). On the opposite end face 43 there is a reflection with corresponding angles of incidence and reflection. The reflected ultrasound wave is reflected at cracks 9 at different depths with respect to the face 27 in the railway wheel 1 either to the first reception ultrasound transducer 33 or to the further reception ultrasound transducer 35 assigned to the first transmission ultrasound transducer 31. With a corresponding reception signal in the first reception ultrasound transducer 33 or the further assigned reception ultrasound transducer 35, the existence of a crack 9 can be concluded.

The first reception ultrasound transducer 33 and the further assigned reception ultrasound transducer 35 are operated together with the first transmission ultrasound transducer 31 in tandem technology. Their distances from the first transmitting ultrasound transducer 31 are adapted to the desired test depth (wheel rim width).

The first transmit ultrasound transducer 31 can also be operated in such a way that a reflected portion of a second ultrasound wave 45 radiated by it (insonification angle α ₂ ) can be received again by the first transmit ultrasound transducer 31 only after reflection from a crack (reception angle β ₂ ), eg in 45 ° pulse echo technology. A crack 44 close to the opposite end face 43 can thus be detected particularly efficiently.

If there is no crack 9 or only a small crack 9, then at least part of the ultrasound wave reflected back from the opposite end face 43 is received by the second received ultrasound transducer 37. The output signal of this second receiving ultrasound transducer 37 is used especially for the detection of a crack oriented as desired with respect to the axis of rotation of the railway wheel 1 and / or for the detection of ren of a crack 44 in the vicinity of the opposite end face 43.

The second receiving ultrasound transducer 37 namely works together with the first transmitting ultrasound transducer 31 under V-transmission with a third ultrasound wave 46, which may be irradiated separately. The third ultrasound wave 46, which in the example shown is irradiated in a spatially overlapping manner with the second ultrasound wave 45 is radiated in at a coupling point 49 and received at a receiving point 51 different from the coupling point 49. The distance between the coupling point 49 and the receiving point 51 is selected such that a reflected portion of the third ultrasonic wave 46 can reach the second receiving ultrasound transducer 37 at the receiving point 51 (receiving angle β ₃ ) as a function of the third insonification angle α ₃ . Cracks of any orientation lead to shadowing and are therefore detectable.

The first insonification angle oti of the first ultrasonic wave 41 has a value in the range from 35 ° to 60 ° and is approximately 45 ° in the exemplary embodiment. In the exemplary embodiment, the third insonification angle α _{3 of} the third ultrasonic wave 46 is selected to be equal to the first insonification angle oti. The third incidence angle α ₃ can have a value in the range from 35 ° to 60 °.

The first reception angle βi at the first reception ultrasound transducer 33 is likewise set to approximately + 45 °. The third reception angle β ₃ on the second reception ultrasound transducer 37 is set to -45 °.

The creeping wave ultrasound transducer 39 radiates an ultrasound creeping wave 47 with a fourth insonification angle α ₄ into the railroad wheel 1, which spreads along the surface of the end face 27. Cracks in Ringer depth below the end face 27 detectable. The fourth insonification angle α is approximately 70 °.

A reflected portion of the ultrasonic creeping wave 47 is detected by the creeping wave ultrasound transducer 39 or preferably by a separately available ultrasound transducer which is not shown explicitly for illustrative reasons.

Inner probe 29B also includes five (not shown) ultrasonic transducers, each the same

Function as the ultrasonic transducers arranged in the outer test head 29A.

The outer test head 29A is adjusted such that a zone near the tread near the tread 2 is tested. The inner test head 29B checks a zone near the surface on the inner circumference 53 of the wheel rim 22. The ultrasonic transducers in each case one of the test heads 29A, 29B are essentially lined up along a straight line 40A or 40B perpendicular to the radius R.

In the exemplary embodiment shown in FIGS. 3 and 4, the first transmit ultrasound transducer 31, the first receive ultrasound transducer 33 and the second receive ultrasound transducer 37 are arranged along the straight line 40A. As a result, it is possible in a particularly simple manner to operate the first transmit ultrasound transducer 31 both in the tandem method and in the V-transmission method (using the shading effect).

In the second exemplary embodiment shown in FIGS. 5 and 6 (and also in FIG. 7 in a cross-sectional illustration along the line VII-VII of FIG. 5), the combination test head 25 is designed for a wave conversion technique. In this combination test head 25, the test heads 29A, 29B have a first transmit ultrasound transducer 31, which is designed as a group emitter, so that the first input sound angle α.ι and the first reception angle ßi can be varied. The first transmission ultrasound transducer 31 can be operated in such a way that the first ultrasound wave 41 transmitted by it can be received by the first transmission ultrasound transducer 31 after reflection on an opposite end face 43 and wave conversion at the crack 9. The first insonification angle oti and the first reception angle βi are varied in order to detect cracks 9 lying at different depths below the end face 27. Here, the first insonification angle oti is preferably pivoted within an interval of 10 ° to 40 °.

A second (receiving) ultrasonic transducer 37 and a creeping wave ultrasonic transducer 39 are operated as in the embodiment shown in FIGS. 2 and 3.

FIG. 7 shows how the test heads 29A, 29B are arranged in the radial direction. The radiation lobe of the outer test head 29A sweeps over the tread 2, that of the inner test head 29B over the inner circumference 53.

In the embodiments of Figures 3 to 7, the railway wheel 1 is designed as a full wheel. FIGS. 8 to 13 illustrate the testing of a railway wheel 1, which is composed of a wheel body (wheel disc) 60 and a wheel tire 62 placed thereon. A rubber body 63 is arranged between the wheel body 60 and the wheel tire 62.

A combination probe 25 is so on the inside

End face 27 of the railroad wheel 1 is arranged to be checked in the area of the outer circumference of the railroad wheel 1, ie in the vicinity of the tread 2, and in the vicinity of the inner circumference 61 of the wheel tire 62. For reasons of clarity, only the irradiation of the first ultrasonic wave 41 and the irradiation of further first ultrasonic waves 64, 66, 68 are shown in FIGS. 8 to 13. In doing so the first ultrasonic wave 41 and one of the further first ultrasonic waves 68 are radiated into the railway wheel 1 such that a possible crack 9 is irradiated from both sides. This advantageously increases the reliability of the method according to the invention by greatly reducing the influence of a curvature of the crack surface on the detection result. Depending on the type of curvature, either the sound from one side or the other leads to a clear reception signal. The sound from both sides can also lead to redundant detection on both sides.

In the exemplary embodiment shown in FIGS. 8 to 10, the first ultrasonic transducer 31 and the first receiving ultrasonic transducer 33 are operated in tandem technology (analogously to FIG. 4). In the exemplary embodiment shown in FIGS. 11 to 13, the second receive ultrasound transducer 33 is omitted, and the first transmit ultrasound transducer 31 can also be operated in the receive mode for a wave conversion technique (analogously to FIG. 6).

In the exemplary embodiment shown in FIG. 14, the railroad wheel 1 is the wheel of a railroad train 70, which is moved on a rail 72, for example in a maintenance hall (not shown), at a constant driving speed V of approximately 1 to 5 km / h. A test car 74 can be moved laterally next to the train 70 on a separate test rail 76 in the direction 78 in synchronism with the train 70. The test carriage 74 can be driven by the moving railroad train 70 via a driver arm 82 which can be latched or latched onto the railroad train 70.

Two combination test heads 25 are fastened to the test carriage 74 via two adjustable, spring-mounted cantilevers 80, with which the two railroad wheels 1 of a bogie of the railroad train 70 are tested simultaneously. The test carriage 74 can be moved such that the position of the combination Test heads 25 on the front side 27 of the railway wheels 1, which is on the outside with respect to the railway train 1, remain unchanged. In other words: the end face 27 rotating when the railroad train 70 is moving moves away under the respective combination test head 25.

In the event of a slight change in the driving speed V, the combination test heads 25 also remain unchanged in their position on the railroad train 70.

A test car 74 is shown in FIG. 15, which is movably arranged below the railroad train 70. The railroad train 70 is shown in cross section.

The test car 74 travels in a maintenance shaft 84, on the side walls of which the rail 72 of the railroad train 70 is raised.

Claims

claims

1. A method for the detection of a crack (9) in a railway wheel (1), in particular for the detection of a crack originating from the tread (2), a first ultrasonic wave (41) in the essentially tangential to the wheel circumference, inclined with respect to an end face (27) of the railway wheel (1) and radiated through the end face (27) at a first incidence angle (otι), and by a first reception ultrasound transducer (33) arranged on the end face (27) is received with a first reception angle (ßi), the first insonification angle (otι) and the first reception angle (ßi) being selected such that the first ultrasonic wave (41) can be received if there is a reflection on the opposite end face (43) and one backward deflection at the crack (9).

2. The method according to claim 1, characterized in that the first insonification angle (oti) and the first reception angle (ßi) are selected such that the first ultrasonic wave (41) can be received if the rearward deflection on a parallel to the axis of rotation (3) of the Railway wheel (1) oriented crack (9) due to a wave conversion.

3. The method according to claim 2, so that the first transmit ultrasound transducer (31) and the first receive ultrasound transducer (33) are identical.

4. The method according to any one of claims 1 to 3, characterized in that the first insonification angle (otι) and the first reception angle (ßi) are varied to detect an unknown crack (9) lying deep below the end face (27).

5. The method according to claim 1, characterized in that the first insonification angle (oti) and the first reception angle (ßi) are selected such that the first ultrasonic wave (41) is receivable if the rearward deflection on a parallel to the axis of rotation (3) of the Railroad wheel (1) oriented crack (9) by reflection with a matching angle of incidence and angle of exit.

6. The method according to claim 5, characterized in that for detecting an unknown deep below the end face (27) lying crack (9) either at least one further, the first transmitting ultrasound transducer (31) associated receiving ultrasound transducer (35) or at least a further transmission ultrasound transducer assigned to the first reception ultrasound transducer (33) is used.

7. The method according to any one of claims 1 to 6, characterized in that a second ultrasonic wave (45) substantially tangential to the wheel circumference, with respect to the end face (27) of the railroad wheel (1) and inclined with a second angle of incidence (ot ₂ ) through the end face (27) radiated in and received at a second reception angle (ß ₂ ) on the end face (27), the second insonification angle (α ₂ ) and the second reception angle (ß ₂ ) being selected such that the second ultrasonic wave ( 45) can be received if the only deflection in the railroad wheel (1) is reflection from a crack which is oriented obliquely or perpendicularly with respect to the axis of rotation (3) of the railroad wheel (1).

8. The method according to claim 7, characterized in that the second insonification angle (ot ₂ ) and the second reception angle (ß ₂ ) are chosen to be the same size.

9. The method according to any one of claims 1 to 6, characterized in that a third ultrasonic wave (46) at a coupling point (49) substantially tangential to the wheel circumference, with respect to the end face (27) of the railroad wheel (1) and inclined with a third insonification angle ( α ₃ ) is radiated through the end face (27) and received at a receiving point (51) different from the coupling point (49) at a third reception angle (β ₃ ) on the end face (27), the third insonification angle (ct ₃ ) and the third reception angle (ß ₃ ) are selected such that the third ultrasonic wave (46) can be received without a crack present after reflection on the opposite end face (43) and without further deflection in the railway wheel (1), and that upon reception who is weakened with respect to the reception without a crack present, it is concluded that there is a crack.

10. The method according to any one of claims 1 to 9, characterized in that an ultrasonic creeping wave (47) through the end face (27) is radiated substantially tangentially to the wheel circumference, and that in the event of a creeping wave echo to the presence of a crack with a small depth dimension with respect the end face (27) is closed.

11. The method according to any one of claims 1 to 10, characterized in that in a railway wheel designed as a full wheel (1), the first ultra-sound wave (41) in the region of the outer circumference of the railway wheel (1), and a further first ultrasonic wave in the region of the inner circumference (53) of the wheel rim (22) are irradiated.

12. The method according to any one of claims 7 to 11, characterized in that in a railway wheel designed as a full wheel (1), the second ultra Sound wave (45) in the area of the outer circumference of the railway wheel (1), and a further second ultrasonic wave in the area of the inner circumference (53) of the wheel rim (22) can be radiated.

13. The method according to any one of claims 9 to 12, characterized in that in a railway wheel designed as a full wheel (1), the third ultrasonic wave (46) in the region of the outer circumference of the railway wheel (1), and a further third ultrasonic wave in the region of the inner circumference (53) of the wheel rim (22) are irradiated.

14. The method according to any one of claims 10 to 13, characterized in that in a railway wheel designed as a full wheel (1), the ultrasonic creeping wave (47) in the region of the outer circumference of the railway wheel (1), and a further ultrasonic creeping wave in the region of the inner circumference (53 ) of the wheel rim (22).

15. The method according to any one of claims 1 to 14, characterized in that in a railway wheel (1) composed of a wheel body (60) and an attached wheel tire (62), the first ultrasonic wave (41) in the region of the outer circumference of the railway wheel (1), and a further first ultrasonic wave is radiated in the region of the inner circumference (61) of the wheel tire (62).

16. The method according to any one of claims 7 to 15, characterized in that in the case of a railway wheel (1) composed of a wheel body (60) and an attached wheel tire (62), the second ultrasonic wave (45) in the region of the outer circumference of the railway wheel (1 ) , and a further second ultrasonic wave can be radiated in the area of the inner circumference (61) of the wheel tire (62).

17. The method according to any one of claims 9 to 16, characterized in that in a railway wheel (1) composed of a wheel body (60) and an attached wheel tire (62), the third ultrasonic wave (46) in the region of the outer circumference of the railway wheel (1), and a further third ultrasonic wave is radiated in the region of the inner circumference (61) of the wheel tire (62).

18. The method according to any one of claims 10 to 17, characterized in that in a railway wheel (1) composed of a wheel body (60) and an attached wheel tire (62), the ultrasonic creep wave (47) in the region of the outer circumference of the railway wheel (1), and a further ultrasonic creeping wave can be radiated in the area of the inner circumference (61) of the wheel tire (62).

19. The method according to any one of claims 1 to 18, characterized in that the railroad wheel (1) is the wheel of a railroad train (70) which is moved at a driving speed (V), and in that for irradiating the first ultrasonic wave (41 ) provided test head (29A, 25) is moved in the direction of travel (78) and at the driving speed (V) such that the position of the test head (29A, 25) with respect to the end face (27) remains unchanged.

20. The method according to any one of claims 7 to 19, characterized in that the railroad wheel (1) is the wheel of a railroad train (70) which is moved at a driving speed (V) and that one for irradiating the second ultrasonic wave (45 ) provided test head (29A, 25) in the direction of travel (78) and with the driving speed (V) is moved such that the position of the test head (29A, 25) with respect to the end face (27) remains unchanged.

21. The method according to any one of claims 9 to 20, characterized in that the railroad wheel (1) is the wheel of a railroad train (70) which is moved at a driving speed (V), and that one intended for irradiation of the third ultrasonic wave (46) The test head (29A, 25) is moved in the direction of travel (78) and at the driving speed (V) such that the position of the test head (29A, 25) with respect to the end face (27) remains unchanged.

22. The method according to any one of claims 10 to 21, characterized in that the railroad wheel (1) is the wheel of a railroad train (70) which is moved at a driving speed (V), and that a test provided for irradiation of the ultrasonic creeping wave (47) - Head (29A, 25) in the direction of travel (78) and with the driving speed (V) is moved such that the position of the test head (29A, 25) with respect to the end face (27) remains unchanged.

23. Device for carrying out the method according to one of claims 1 to 22, with a test head (29A, 25) which can be placed on the end face (27) of the railway wheel (1),

- on which the first transmitting ultrasound transducer (31) and the first receiving ultrasound transducer (33) and - optionally at least one ultrasound transducer (31) for a second ultrasound wave (45) and

- optionally at least one ultrasonic transducer (31) for a third ultrasonic wave (46) and / or

- Optionally, an ultrasonic transducer (39) for an ultrasonic creeping wave (47) are arranged.

24. Device for carrying out the method according to one of claims 11 to 18, with a combination test head (25) which can be placed on the end face (27) of the railway wheel (1),

- On the ultrasonic transducer (31) for irradiating and receiving the first ultrasonic wave (41) and the other first

Ultrasonic wave

- and optionally ultrasonic transducer (31) for irradiating and receiving a second ultrasonic wave (45) and a further second ultrasonic wave - and optionally ultrasonic transducer (31) for irradiating and receiving a third ultrasonic wave (46) and a further third ultrasonic wave

- and optionally ultrasonic transducers (39) for irradiating and receiving an ultrasonic creeping wave (47) and a further ultrasonic creeping wave are arranged.

25. Device according to one of claims 23 or 24, so that at least one of the ultrasonic transducers (31, 33, 35, 37, 39) is a piezoelectric transducer.

26. Device according to one of claims 23 to 25, characterized by a test carriage (74) arranged laterally next to or below the railroad train (70) and movable in its direction of travel (78), on which the test head (29A, 29B) or optionally the combination Test head (25) can be attached.

27. The apparatus according to claim 26, characterized in that the test head (29A, 29B) or the combination test head (25) from the test carriage (74) on the inside (with respect to the railroad train (70) end face (27) of the railroad wheel (1) is attachable.

28. The apparatus of claim 26 or 27, so that the test car (74) is drivable by the moving train (70).

29. Device for detecting a crack in a railroad wheel (1), in particular for detecting a crack originating from the tread (2), with a) a first transmission ultrasound transducer (31), b) a first reception ultrasound transducer (33), which can be operated together with the first transmit ultrasound transducer (31) using the tandem method, c) a second receive ultrasound transducer (37) which can be operated together with the first transmit ultrasound transducer (31) using the V-transmission method , wherein the first transmission ultrasound transducer (31), the first reception ultrasound transducer (33) and the second reception ultrasound transducer (37) are arranged essentially along a straight line (40A).

30. Device for the detection of a crack in a railway wheel (1), in particular for the detection of a crack originating from the tread (2), with a) a first transmitter-ultrasound transducer (31) designed as a group emitter, which can also be operated as a receiver for a wave conversion method b) a second reception ultrasound transducer (37) which can be operated together with the first transmission ultrasound transducer (31) using the V-transmission method.

31. Device for detecting a crack in a railroad wheel (1), in particular for detecting a crack originating from the tread (2), with a first transmission ultrasound transducer (31) designed as a group radiator, which at the same time serves both as a receiver for a wave conversion process and can also be operated as a receiver for a pulse-echo method with back reflection.