DE102017105477A1 - Method for nondestructive detection of a contact surface of contacting first and second bodies, in particular of contact patterns in contacting components, for. B. at gears - Google Patents

Abstract

A method for non-destructive detection of a contact surface of contacting first and second bodies, in particular contact patterns in contacting components, for example in gears, comprising: applying a luminescent agent to a region comprising an assumed contact surface of the first body and a luminescent agent on one A region comprising an assumed contact surface of the second body, moving, in particular rotating, the first body relative to the second body, so that at least a portion of the luminescent agent is transferred from the first body to the second body, and detecting luminescence effects in the second body with a Sensor to determine the contact surface.

Description

The present invention relates to a method for detecting a surface of contacting first and second bodies, in particular of contact images in the case of contacting components, for example in the case of toothed wheels.

Surfaces of various kinds come into contact with each other in many industrial areas as well as in everyday life. Rolling or sliding touch operations can be found, for example, in gears, belt and chain drives, bearings, and when moving on roads or rails (for example, tires, wheels, footwear).

As a rule, torques and / or mechanical energy are transmitted. Energy losses and / or friction and / or wear and / or damage and / or noise are to be reduced. For this it is necessary to know the contact surfaces involved as accurately as possible. For example, in a transmission, the teeth of the gears should not touch (exclusively) at their corners. Otherwise, breakage and thus high costs are likely. In the case of tires or wheels rolling on a surface, their full width should be involved in the contact, both on a straight line and in curves, in order to achieve the best possible grip with the ground. If the materials involved are not transparent, the contact surface of the relevant components is not observable.

1. a) Pastenmethode: die Bauteile, welche miteinander in mechanischen Kontakt treten, werden mit einer Paste bestrichen, die sich in Folge des mechanischen Kontakts abreibt. Nach dem Kontakt zeigt der Flächenanteil ohne Lack den Kontaktbereich an. Ein derartiges Verfahren ist in DE 10 2009 023 722 A1 für den Anwendungsfall „Tragbildanalyse von Zahnrädern“ beschrieben.
2. b) Farbsprühmethode: In US 5373735 A1 wird eine Vorrichtung beschrieben, bei der Zähne eines Zahnrades in einem Getriebe vor dem Kontakt mit einer Farbe besprüht werden, die sich bei Abwälzen auf die Flanken des Gegenzahnrades abträgt, was sich nach dem Kontakt mit einer Anordnung aus Beleuchtung und Kamera als „Fußabdruck“ des Kontakts detektieren lässt.
3. c) Thermographische Methoden: Diese beruhen auf der Detektion von Reibungswärme bzw. auf der Übertragung von Wärme, die zuvor in eines der kontaktierenden Bauteile zum Beispiel mit leistungsstarken Lasern eingebracht wurde. DE 36 38 726 A1 offenbart beispielsweise ein derartiges Verfahren.

For the non-destructive determination of contact surfaces of contacting bodies, in particular components, three solution statements are known in principle:

1. a) paste method: the components, which come into mechanical contact with each other, are coated with a paste, which rubs off as a result of the mechanical contact. After contact, the surface area without paint indicates the contact area. Such a method is in DE 10 2009 023 722 A1 for the application "Contact pattern analysis of gears" described.
2. b) Color Spray Method: In US 5373735 A1 a device is described in which the teeth of a gear in a transmission are sprayed prior to contact with a paint that wears off when rolling on the flanks of the counter gear, resulting in contact with an arrangement of lighting and camera as a "footprint" of Can detect contact.
3. c) Thermographic methods: These are based on the detection of frictional heat or on the transfer of heat, which was previously introduced into one of the contacting components, for example with high-performance lasers. DE 36 38 726 A1 for example, discloses such a method.

The paste method is established, for example, in the contact pattern inspection of gearboxes. However, it is considered time-consuming and thus costly and cumbersome to document. In addition, it provides, for example in transmissions only information about the contacts of a tooth flank with many tooth flanks of the counter gear, that is not an individual contact pattern, but only a "Summentragbild".

In the above-mentioned color spraying method, the spraying operation must be repeated several times if individual supporting patterns are to be checked. An increase in the amount of ink on the flanks is to be expected, so that the paint on the flanks dissolves due to surface tensions or forces (for example, centrifugal force, gravity). Because the spraying process can not take place arbitrarily fast, the speed of the gears during contact testing is limited.

Passive thermographic methods require frictional heat of the contact surfaces, which hardly appears during rolling movements. Moreover, like the paste method, they only provide information averaged over many touch operations.

In Prekel, H.; Goch, G .; Lipinski, R .; Thiemann, P .: Modeling of a laser-assisted contact pattern analysis. In: VDI Wissensforum GmbH (ed.): VDI reports, volume 2236, 5 , Fachachtung Verzahnungsmesstechnik, Nürtingen, VDI Verlag, Dusseldorf, 2014, the suitability of active thermographic processes, which are not dependent on friction, was investigated with the help of simulation calculations. It has been found that for the heat transfer between the components involved (teeth of gears) as large as possible instantaneous contact surface and sufficient contact times are required, so that the method is suitable for example in large gears. Objects in which the current contact surfaces are small and only touch for a short time (for example, gear pairs in small gears at high speeds), are unsuitable for this method.

The present invention is therefore based on the object of providing a method which determines the contact surface of bodies largely independently of their size and contact side. The contact surface to be determined is also referred to as a "contact pattern" in the case of toothed wheels.

According to the invention, this object is achieved by a method for non-destructive detection of a contact surface of contacting first and second bodies, in particular of contact images in the case of contacting components, for example in the case of toothed wheels, comprising applying a luminescent agent to a region comprising an assumed contact surface of the first body and a luminescent agent on a region comprising an assumed contact surface of the second body, moving, in particular turning, the first body relative to the second body, so that at least a part of the luminescent agent is transferred from the first body to the second body, and detecting of luminescence effects on the second body with a sensor to determine the touch area.

For example, the sensor may be a camera, such as a camera. a matrix, line, or scanner camera.

According to a particular embodiment it can be provided that the application comprises a deactivation of the luminescence means. This serves to eliminate an existing residual luminescence.

Furthermore, according to a particular embodiment of the present invention, it can be provided that the method additionally comprises exciting or activating the luminescence medium applied to the first body.

In particular, it can be provided that the stimulation or activation of the applied luminescent agent comprises irradiation with electromagnetic radiation.

Advantageously, the luminescence effects are actively limited in time.

According to a particular embodiment of the present invention, the, preferably identical, luminescent agents are phosphorescent substances, in particular suspensions with phosphorescent particles.

On the other hand, it can also be provided that the method comprises exciting the luminescent agent applied to the first body and additionally exciting the luminescence medium transmitted to the second body, preferably by irradiation with electromagnetic radiation.

In particular, it may be provided that the, preferably identical, luminescent agents are photostimulating substances, in particular suspensions with photostimulating particles.

Again, it may alternatively be provided that the method comprises activating the luminescent agent applied to the first body and additionally exciting the luminescence medium transferred to the second body, preferably by irradiation with electromagnetic radiation.

According to a further particular embodiment of the present invention, the two luminescent agents are different and comprise chemiluminescence effects as luminescence effects.

Finally, it can again be provided in a particular embodiment of the invention that the luminescence effects include triboluminescence effects.

The present invention is based on the surprising findings that luminescence effects for non-destructive detection of contact surfaces of contacting first and second bodies can be used by applying suitable substances capable of luminescence effects or activatable substances to the contacting bodies and, if appropriate, excitation or activation.

Further features and advantages of the invention will become apparent from the appended claims and from the following description in which several embodiments are explained in detail with reference to the schematic drawings.

• 1 ein Ablaufschema eines Verfahrens zum zerstörungsfreien Erfassen eines Tragbilds bei sich berührenden Zahnrädern gemäß einer besonderen Ausführungsform der vorliegenden Erfindung;
• 2 ein Ablaufschema eines Verfahrens zum zerstörungsfreien Erfassen eines Tragbilds bei sich berührenden Zahnrädern gemäß einer weiteren besonderen Ausführungsform der vorliegenden Erfindung;
• 3 ein Ablaufschema eines Verfahrens zum zerstörungsfreien Erfassen eines Tragbilds bei sich berührenden Zahnrädern gemäß einer weiteren besonderen Ausführungsform der vorliegenden Erfindung; und
• 4 ein Ablaufschema eines Verfahrens zum zerstörungsfreien Erfassen einer Berührfläche von einem eine Straße berührenden Fahrzeugrad.

Showing:

• 1 a flow chart of a method for nondestructive detection of a contact pattern in contacting gears according to a particular embodiment of the present invention;
• 2 a flow chart of a method for nondestructive detection of a contact pattern in contacting gears according to another particular embodiment of the present invention;
• 3 a flow chart of a method for nondestructive detection of a contact pattern in contacting gears according to another particular embodiment of the present invention; and
• 4 a flowchart of a method for non-destructive detection of a contact surface of a road-contacting vehicle wheel.

1a ) shows touching first and second bodies 10 and 12 , It is in this example to two meshing gears. As a contact pattern of a tooth flank of a gear designated according to DIN 3871, the contact area formed during the rolling process with a counter flank of a second gear. To determine the contact pattern involved areas 14 respectively. 16 having a respective assumed contact surface of the first body 10 and the second body 12 with a luminescent agent 18 and 20 wetted in this example in the form of a phosphorescent substance and optionally, for example, by means of an emitted from a radiation source 22 electromagnetic radiation 23 first heated and thus deactivated to eliminate any existing residual luminescence.

In 1b ) becomes the luminescent agent 18 on the first body 10 , preferably spatially, for example locally, limited, by means of, for example, electromagnetic radiation 24 from a radiation source 25 to luminescence effects, in particular luminaires, excited Upon contact of the first and second bodies 10 and 12 by rotational drive (see the arcuate arrows) of at least one of the first and second bodies 10 and 12 the luminescent agents mix 18 and 20 the contact surfaces, so that the excited luminescence 18 at least partially from the first body 10 on the second body 12 is transmitted. The luminous surface corresponds to the contact surface. The wetting of the contact surfaces of the first and second bodies should be so thin that no significant displacement of the movie takes place.

In the present example, the luminescent agents 18 and 20 identical and comprise a phosphorescent substance. Especially with repeated contacts (for example with gears) it may be necessary to limit the phosphorescence in time. This may be, for example, thermal (heating, for example, with a radiation source 26 , z. B. a laser). The radiation sources 22 and 26 may be the same or even identical. By this measure, the phosphorescent light is emitted in a shorter time, making it appear brighter and even better by means of a camera 28 is detectable. Phosphorescent substances are mostly insoluble. Therefore come as suitable substances primarily suspensions with phosphorescent particles in question.

In the in the 2 As shown, photostimulable substances are used. In other words, the luminescent agents 18 and 20 around (preferably similar) photostimulable substances. The substances may differ from embodiment to embodiment. Within one embodiment, however, the contacting surfaces are wetted with similar substances that differ only in their state ("activated", "not activated"). Just as with the method according to 1 the contact surfaces involved are wetted with the photostimulable substance thin and possibly first by means of (eg near-infrared) electromagnetic radiation 32 from a radiation source 30 , z. As an NIR source disabled (see 2a )). Thereafter, the wetted surface of the first body 10 with electromagnetic radiation 24 , eg light, from a radiation source 25 activated or charged (see 2 B )). Upon contact of the meshing gears, the photostimulable substances of both surfaces mix. The activated luminescent agent 18 is at least partially from the first body 10 to the second body 12 transfer. Part of the excitation energy is released over a very long period of time (possibly many hours) as a longer-wave light, so that the intensity is very low and barely perceptible. This light emission is irrelevant for the contact examination.

After contact, the surface of the second body 12 with activated luminescent agent thereon 18 with (for example, near-infrared) electromagnetic radiation 32 from a radiation source 33 illuminated (see 2c )), whereby the activated luminescent agent 18 on the second body 12 is stimulated to emit electromagnetic radiation, so that the contact surface is visually apparent and with a camera 28 becomes detectable (see 2c )). The radiation sources 30 and 33 can be the same or even identical. Which radiation wavelengths are suitable depends on the respective substances used. There are substances that can be "charged" with visible light and stimulated with infrared light to emit orange-red light. Such substances are used, for example, in the localization of near-infrared laser beams. As in the method according to 1 come here primarily suspensions in question. These photostimulable substances include materials that are available under different names, such as "long afterglow phosphor" and "storage phosphor", respectively.

In the method according to the 3 becomes a switchable dye or switchable dyes as luminescent 18 and 20 used. Various luminescent substances have their properties "switched" by external influences (eg light). In particular, it is possible for some substances to switch their ability to fluorescence on or off or to switch their absorption or emission wavelengths. Such substances are found, inter alia, in the class of proteins, such as the "green fluorescent protein "(GFP) and various mutations thereof. Thus, for example, the substance called "DRONPA" emits green fluorescent light when illuminated with radiation of about 488 nm.

Bit by bit, however, DRONPA turns into a non-fluorescent state upon irradiation with excitation light. Although further irradiation at a different wavelength near 405 nm does not itself lead to appreciable fluorescence, it does convert DRONPA back into a state which is capable of fluorescence upon excitation at about 488 nm.

The detection of the contact surface can now, as illustrated by the example of a contact image analysis of gears (see 3 ) (if other substances than DRONPA are used, other wavelengths may apply):

Phase 1 ("initialization"): The tooth flanks of both gears (first and second body 10 and 12) are already wetted for example with "DRONPA" thin and are now using electromagnetic radiation 34 from a radiation source 35 irradiated with a wavelength of 488 nm in this example (see 3a )), which deactivates DRONPA. The initially occurring fluorescence gradually decreases. The ability to fluoresce eventually disappears altogether.

Phase 2 ("Activation"): Load flanks of the first gear (first body 10 ) are now using electromagnetic radiation 36 with a wavelength in this example of 405 nm from a radiation source 37 irradiated The protein on this load flank is now ready for fluorescence (see 3b )).

Phase 3 ("Transfer / Detection"): Part of the activated luminescent agent 18 (activated DRONPA) is when rolling on the opposite edges of the second gear (second body 12 ) transfer. After rolling, the counter flanks are irradiated with electromagnetic radiation 38 with a wavelength in this example of 488 nm from a radiation source 39 so that the protein transferred in the contact pattern area lights up. The fluorescence can be detected with a camera 28 record (see 3c )).

In a variant embodiment with chemiluminescence not shown here, the first and second bodies are wetted with different luminescent agents thinly. The luminescent agents must at least partially mix at the contact surfaces and react chemically with the emission of electromagnetic radiation that can be detected to determine the contact surface.

In a further embodiment variant with triboluminescence, which is not shown here, the first and second bodies are wetted with identical luminescent agents which produce triboluminescence upon contact of the first and second bodies. The triboluminescence is used to excite phosphorescence light, which can be detected after contact Tribulomineszenz and phosphorescence can be generated by various as well as similar particles (for example, doped zinc sulfide).

In particular, the embodiments described in the 1 to 3 and the triboluminescence embodiment are also applicable to repeated contacts.

In the embodiments according to the 1 to 3 A contact flank releases so much of its substance to the opposite surface as it receives back from it. In addition, the state of the luminescent agent (bright or luminous) is often or even as often switched. The above-described embodiments are for describing an operation using the example of gears in which substances having a specific state are transmitted from a driving gear to a driven gear. This is mutatis mutandis possible.

As will be understood from the foregoing description, when both gears have an equal number of teeth, one revolution is sufficient to receive the contact images of the intermeshing gears. Otherwise, more than one turn is required.

For deactivation of the luminescent means on the first and second gears is of durations in the order of a few milliseconds to a few seconds when using substances such as in 1 emanating embodiment, these periods are mainly determined by the choice of substances that can - as already described - on external influences something (factor 2 to about 10) can reduce. In embodiments, the luminescent agents as in the 2 In the embodiment shown, deactivation times of the order of about one second are to be expected. However, these time periods are dependent on the laser power and thus probably reduced to a few 10 to 100 milliseconds.

When using luminescent agents similar to the embodiment according to 3 For example, the deactivation periods are expected to be on the order of a few seconds.

When using luminescent agents similar to those in the 1 to 3 shown embodiments of periods for the activation or excitation of a luminescent agent on the first gear in the order of a few milliseconds, possibly even microseconds, go out.

The more luminescent agent is transferred from one body to the other, the more intense the luminescence on the second body (second gear). It is expected to be dependent on the viscosity of the carrier fluid and the test conditions (eg speed). In the best case, a detection time of about 10 milliseconds is assumed, in the worst case of a few seconds.

In the 4 are the first and second bodies 10 and 12 no gears, but a road and a vehicle wheel. In the 4 a vehicle is moving 40 to which the vehicle wheel (second body 12 ), from right to left. In the direction of travel in front of the vehicle wheel (second body 12 ) is one on the vehicle 40 fixed source of radiation 42 and in the direction of travel behind the vehicle wheel (second body 12) is a camera 46 , In addition, the vehicle points 40 between the radiation source 42 and the camera 46 another source of radiation 44 on. The front radiation source 42 serves to activate one on the road (first body 10 ) inactive luminescent agent 18 with electromagnetic radiation 24 , Accordingly, the vehicle wheel (the second body 12 ) is in contact with the activated luminescent means 18 'as it rolls over the road. At least part of the activated luminescent agent passes through it 18 ' over to the vehicle wheel. The luminous areas are determined by the camera 46 picked up and deliver the touch surface. After recording, the activated luminescent agent 18 ' on the vehicle wheel (second body 12 ) by means of the radiation source 44 emitted electromagnetic radiation 45 deactivated again.

The proposed methods allow a fast, automatable and well-documented contact surface inspection, which also allows individual wear patterns instead of Summentragbilderern (example gears). It is independent of frictional heat and can also be used on pairs of components whose momentary contact surfaces are small and only briefly contact each other (example: gears in gears, contact surfaces of tires on the pavement, train wheels on rails, bearings, conveyor belts, chain links in contact with pinions). The device complexity is relatively low, because cost-effective detectors and beam sources exist. In connection with the embodiment according to 2 switchable fluorescent proteins mentioned are only a few years on the market and currently available in small quantities and relatively expensive. However, prices will continue to decrease over time.

The features of the invention disclosed in the present description, in the drawings and in the claims may be essential both individually and in any desired combinations for the realization of the invention in its various embodiments.

LIST OF REFERENCE NUMBERS

10

first body

12

second body

14.16

areas

18, 20

phosphor

18 '

activated luminescent agent

22

radiation source

23

electromagnetic radiation

24

electromagnetic radiation

25

radiation source

26

radiation source

28

camera

30

NIR source

32

electromagnetic radiation

33

radiation source

34

electromagnetic radiation

35

radiation source

36

electromagnetic radiation

37

radiation source

38

electromagnetic radiation

39

radiation source

40

vehicle

42

radiation source

44

radiation source

45

electromagnetic radiation

46

camera

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009023722 A1 [0004]
• US 5373735 A1 [0004]
• DE 3638726 A1 [0004]

Cited non-patent literature

• H.; Goch, G .; Lipinski, R .; Thiemann, P .: Modeling of a laser-assisted contact pattern analysis. In: VDI Wissensforum GmbH (ed.): VDI reports, volume 2236, 5 [0008]

Claims (11)

Method for non-destructive detection of a contact surface of contacting first and second bodies (10, 12), in particular of contact patterns in contacting components, for example in the case of toothed wheels, comprising: Applying a luminescent agent (18) to a region comprising an assumed contact surface of the first body (10) and a luminescent agent (20) on a region comprising an assumed contact surface of the second body (12), Moving, in particular turning, the first body (10) relative to the second body so that at least part of the luminescent means (18) is transferred from the first body to the second body (12), and - Detecting Lumineszenzeffekten the second body (12) with a sensor to determine the contact surface. Method according to Claim 1 wherein the applying comprises deactivating the luminescent means (18, 20). Method according to Claim 1 or 2 wherein it additionally comprises exciting or activating the luminescent agent (18) applied to the first body (10) Method according to Claim 3 wherein energizing or activating the applied luminescent agent (18) comprises irradiating with electromagnetic radiation (24; 36). Method according to one of Claims 1 to 4 , wherein the Lumineszenzeffekte are actively limited in time. Method according to one of the preceding claims, wherein the, preferably identical, luminescent means (18, 20) are phosphorescent substances, in particular suspensions with phosphorescent particles. Method according to one of Claims 3 to 5 wherein it comprises exciting the luminescent means (18) applied to the first body (10) and additionally exciting the luminescent means (18) transferred to the second body (12), preferably by irradiation with electromagnetic radiation (32; 38). Method according to Claim 7 , wherein the, preferably identical, luminescent means (18, 20) photostimulating substances, in particular suspensions with photostimulating particles, are. Method according to one of Claims 3 to 5 wherein it comprises activating the luminescent means (18) applied to the first body (10) and additionally exciting the luminescent means (18) transferred to the second body (12), preferably by irradiation with electromagnetic radiation. Method according to Claim 1 wherein the two luminescent agents are different and include chemiluminescent effects as luminescence effects. Method according to Claim 1 wherein the luminescent effects comprise triboluminescence effects.

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