Method for installing a control probe on an element to be controlled using at least one calibrated shim and equipment for implementing said method

Abstract

Method for placing a control probe on an element to be controlled using at least one calibrated shim and equipment for implementing said method The invention relates to a method for placing a control probe (34) on an element to be controlled (40), the method comprising a step of applying an adhesive (42.1) to couple the control probe (34) and the element to be controlled (40), a step of positioning the control probe (34) relative to the element to be controlled (40) and a step of polymerizing the adhesive (42.1). To obtain an optimal thickness of glue (42.1) at the end of the polymerization step, at least one calibrated shim (46) is inserted between the control probe (34) and the element to be controlled (40), each calibrated shim (46) having a thickness substantially equal to an optimal value of the thickness of the glue (42.1), guaranteeing optimal coupling between the control probe (34) and the element to be controlled (40).The invention also relates to equipment for implementing said method. Figure 5.

Description

Title of the invention: Method for placing a control probe on an element to be controlled using at least one calibrated shim and equipment making it possible to implement said method

[0001] The present application relates to a method for placing a wave control probe on an element to be controlled using at least one calibrated shim as well as to equipment making it possible to implement said method.

[0002] A non-destructive testing system can be used to inspect an element, such as an aircraft structure for example, in order to detect internal defects.

[0003] According to an embodiment visible in [Fig.l], a non-destructive testing system 10 comprises a wave generator 12 as well as a testing probe 14 connected to the wave generator 12 and configured to emit and receive waves 16. In operation, the testing probe 14 is affixed to a surface S of an element to be tested 18 by inserting a coupling material 20 between the testing probe 14 and the element to be tested 18 to optimize the transfer of the waves 16 between the testing probe 14 and the element to be tested 18.

[0004] When the control must be carried out in real time, continuously or periodically, the control probe 14 must be glued to the element to be controlled 18 using a glue 20.1 which ensures the functions of adhesive and coupling material 20.

[0005] According to one operating mode, a first face 14.1 of the control probe 14, oriented towards the element to be controlled 18 in operation, is glued with a polymerizable adhesive 20.1. Generally, the area of ​​the surface S of the element to be controlled 18 to be covered by the control probe 14 is also glued. Next, the control probe 14 is pressed against the surface S of the element to be controlled 18. After polymerization of the adhesive 20.1, the control probe 14 is connected to the element to be controlled 18.

[0006] As long as the glue 20.1 is not completely polymerized, an operator holds the control probe 14 by exerting pressure in the direction of the part to be controlled 18 while keeping the first face 14.1 of the control probe 14 oriented towards the element to be controlled 18, in a manner substantially parallel to the surface S of the element to be controlled 18, while trying to keep it at a predefined distance optimal for the measurements. To accelerate the polymerization, the glue can be heated.

[0007] This procedure is not satisfactory because the polymerization of the glue is not carried out under optimal and controlled conditions. Consequently, the glue may have a non-optimal thickness and / or defects, so that the measurements taken are not optimal. It would therefore be desirable to find a solution allowing to improve the precision of the measurements taken.

[0008] The present invention aims to remedy all or part of the drawbacks of the prior art.

[0009] For this purpose, the invention relates to a method for placing a control probe on a surface of an element to be controlled, the control probe being connected to the element to be controlled by a coupling material in the form of an adhesive configured to occupy a first state in which the adhesive can be applied and a second state, after a polymerization phase, in which the adhesive connects the control probe and the element to be controlled and has a thickness substantially equal to a coupling value to obtain optimal coupling between the control probe and the element to be controlled; the method of placing comprising a step of applying the adhesive, a step of positioning the control probe relative to the element to be controlled and a step of polymerizing the adhesive.

[0010] According to the invention, the installation method comprises a step of positioning at least one calibrated shim inserted between the control probe and the element to be controlled at least before the polymerization step, each calibrated shim having a thickness substantially equal to the optimal value of the thickness of the glue.

[0011] This process makes it possible to simplify the installation of the control probe, to optimize the installation time and to obtain optimal glue thickness and polymerization.

[0012] According to another characteristic, the step of positioning at least one calibrated shim consists of interposing, between the control probe and the element to be controlled, two spaced and substantially parallel wires which each have a diameter equal to the optimal value of the thickness of the glue.

[0013] According to another characteristic, each calibrated shim has a thickness of between 100 and 200 μm, and preferably equal to approximately 150 μm with a tolerance of + / -10%.

[0014] According to another characteristic, during at least part of the polymerization step, a calibrated force is applied to the control probe in the direction of the element to be controlled so that each calibrated shim is simultaneously in contact with the element to be controlled and the control probe.

[0015] According to another characteristic, the polymerization step is carried out under a regulated atmosphere.

[0016] According to another characteristic, the regulated atmosphere has an optimal regulated temperature for the glue polymerization step.

[0017] According to another characteristic, the control probe is positioned in an enclosure containing a regulated atmosphere during at least part of the step of polymerization.

[0018] The invention also relates to equipment making it possible to implement a method for installing a control probe according to one of the preceding characteristics. According to the invention, this equipment comprises a positioning tool which comprises a housing configured to house a control probe as well as at least one calibrated shim, connected to the positioning tool, configured to be inserted between the control probe and the element to be controlled.

[0019] According to another characteristic, the positioning tool comprises a body which has first and second opposite faces, the housing opening at the first and second faces and having a cross-section substantially identical to that of the control probe.

[0020] According to another characteristic, the positioning tool comprises at least two spaced and substantially parallel wires, each forming a calibrated shim, connected to the body, passing through the housing and positioned at the first face of the body.

[0021] According to another characteristic, the equipment comprises a pressure system configured to apply a calibrated force on the control probe in the direction of the element to be controlled.

[0022] According to another characteristic, the pressure system comprises at least one object of calibrated mass positioned on the control probe.

[0023] According to another characteristic, the equipment comprises at least one heating system for heating the glue and / or a regulated atmosphere in which the glue is positioned.

[0024] According to another characteristic, the heating system is positioned in the body, close to the first face of the body configured to be oriented towards the element to be controlled in operation.

[0025] According to another characteristic, the equipment comprises at least one temperature sensor configured to measure the temperature of the glue and / or of a regulated atmosphere in which the glue is positioned in order to control the heating system.

[0026] According to another characteristic, the temperature sensor is positioned in the positioning tool, close to the first face of the body.

[0027] According to another characteristic, the equipment comprises at least one enclosure sized to house the positioning tool in which the control probe is positioned.

[0028] Other characteristics and advantages will emerge from the description of the invention which follows, a description given by way of example only, with reference to the appended drawings, among which:

[0029] [Fig-1] is a schematic side view of a non-destructive testing system by waves and an element to be tested illustrating an embodiment of the prior art,

[0030] [Fig.2] is a schematic side view of a non-destructive wave testing system and an element to be tested illustrating an embodiment of the invention,

[0031] [Fig.3] is a schematic top view of the non-destructive wave testing system and the element to be tested visible in [Fig.2],

[0032] [Fig.4] is a schematic top view of holding and polymerization equipment and a test probe illustrating an embodiment of the invention,

[0033] [Fig.5] is a schematic side view of a holding and polymerization equipment and a control probe illustrating an embodiment of the invention,

[0034] [Fig.6] is a top view of a portion of a positioning tool illustrating an embodiment of the invention,

[0035] [Fig.7] is a top view of a control probe positioned in the positioning tool visible in [Fig.6],

[0036] [Fig.8] is a schematic representation of the different steps of a method of installing a control probe illustrating an embodiment of the invention.

[0037] According to an embodiment visible in Figures 2 and 3, a non-destructive testing system 30 comprises a wave generator 32, a testing probe 34 connected to the wave generator 32 and configured to emit and receive waves 36 as well as a processing unit 38 configured to process the signals emitted by the testing probe 34. In operation, the testing probe 34 is affixed to a surface S of an element to be tested 40 by inserting a coupling material 42 between the testing probe 34 and the element to be tested 40 to optimize the transfer of the waves 36 between the testing probe 34 and the element to be tested 40.

[0038] According to one application, the element to be controlled 40 is a structure of an aircraft.

[0039] The control probe 34 comprises a first face 34.1 oriented towards the element to be controlled 40 in operation. This first face 34.1 corresponds to the face of the control probe from which the waves 36 are emitted and received. This first face 34.1 is generally flat.

[0040] According to one configuration, the control probe 34 is substantially parallelepipedal. According to a variant visible in [Fig. 7], the control probe 34 is substantially parallelepipedal and has a first face 34.1 oriented towards the element to be controlled 40, a second face 34.2 opposite the first face 34.1, lateral faces 34.3 connecting the first and second faces 34.1, 34.2, perpendicular two by two, as well as cut sides 34.4, 34.4' at the junction zones of the lateral faces 34.3. According to one configuration, the control probe 34 comprises at least one keying device. For example, a cut side 34.4' larger than the other cut sides 34.4 can form a deceiver.

[0041] In a plane parallel to the first face 34.1, the control probe 34 has a cross section.

[0042] According to one configuration, the wave generator 32 is an ultrasonic wave generator and the control probe 34 is a conventional or multi-element type ultrasonic probe.

[0043] The wave generator 32, the control probe 34 and the processing unit 38 are not described further because they are known to those skilled in the art and may be identical to those of the prior art.

[0044] According to applications, when the control must be carried out in real time, continuously or periodically for example, the control probe 34 is permanently connected to the element to be controlled 40 using a glue 42.1 which ensures the functions of adhesive and coupling material 42.

[0045] This glue 42.1 is configured to have a pasty or liquid, uncured state, allowing its application as well as a cured state allowing the control probe 34 and the element to be controlled 40 to be securely connected. According to one embodiment, the glue 42.1 is a polymerizable glue and changes from the pasty state to the cured state during a polymerization step.

[0046] For the present application, polymerization is understood to mean a step of transforming the glue 42.1 from a first state in which it can be applied and a second state in which it securely connects the control probe 34 and the element to be controlled 40.

[0047] For example, the glue 42.1 is chosen from the family of epoxy glues.

[0048] To optimize the mechanical connection and an optimal transfer of the waves 36 between the control probe 34 and the element to be controlled 40, the adhesive 42.1 must have, after the polymerization step, a thickness (distance separating the surface S of the element to be controlled 40 and the first face 34.1 of the control probe 34) substantially equal to a coupling value. To give an order of magnitude, the coupling value is between 100 and 200 μm, and preferably is equal to approximately 150 μm with a tolerance of + / - 10%. This coupling value may be different from one adhesive to another.

[0049] Depending on the area to be inspected of the element to be controlled 40, the control probe 34 is positioned on the surface S according to a given position and orientation.

[0050] A method of placing the control probe 34 on the surface S of the element to be controlled 40 comprises a step of applying the glue 42.1 in a non-polymerized state between the control probe 34 and the surface S of the element to be controlled 40, a step of positioning the control probe 34 relative to the element to be controlled 40 according to the given position and orientation as well as a step of polymerizing the glue 42.1 so that the control probe 34 is connected to the element to be controlled 40 and immobile relative to the latter.

[0051] According to one method of operation, during the step of applying the glue 42.1, at least one surface among the first face 34.1 of the control probe 34 and an area of ​​the surface S of the element to be controlled 40, for example that covered by the control probe 34, is glued. According to one configuration, the first face 34.1 of the control probe 34 and the area of ​​the surface S of the element to be controlled 40 are glued, as illustrated in parts (B) and (C) of [Fig.8]. According to one embodiment, a stencil 44 is applied to the surface S prior to its gluing, as illustrated in part (B) of [Fig.8].

[0052] Prior to the step of applying the glue 42.1, each surface to be glued is prepared in order to promote the adhesion of the glue 42.1.

[0053] According to a feature of the invention, the installation method comprises a step of positioning at least one calibrated shim 46 interposed between the control probe 34 and the element to be controlled 40 at least before the polymerization step. This calibrated shim 46 has a thickness substantially equal to the coupling value of the thickness of the glue 42.1 to obtain optimal coupling. According to one embodiment, each calibrated shim 46 has a thickness of between 100 and 200 μm, and preferably equal to approximately 150 μm with a tolerance of + / - 10%.

[0054] According to one arrangement, at least two calibrated shims 46 of the same thickness are interposed between the control probe 34 and the element to be controlled 40.

[0055] In order not to disturb the measurements, each calibrated shim 46 is a wire. In this case, the step of positioning at least one calibrated shim 46 consists of interposing, between the control probe 34 and the element to be controlled 40, two spaced and substantially parallel wires which each have a diameter equal to the coupling value of the thickness of the glue 42.1 to obtain optimal coupling. According to one embodiment, each wire is a polyamide wire, in particular transparent.

[0056] During at least part of the polymerization step, a calibrated force 48 is applied to the control probe 34 in the direction of the element to be controlled 40 so that each calibrated shim 46 is simultaneously in contact with the surface S of the element to be controlled 40 and the control probe 34. This calibrated force 48 is applied until the glue 42.1 is sufficiently hardened so that the control probe 34 is immobile relative to the element to be controlled 40. The calibrated force 48 is applied until the glue 42.1 has completely hardened, in particular until the glue 42.1 is completely polymerized.

[0057] According to one embodiment, at least one pressure system 50 is used to apply this calibrated force 48. According to one embodiment, the pressure system 50 comprises at least one object of calibrated mass 50.1 positioned on the second face 34.2 of the control probe 34. This solution makes it possible to apply a calibrated force 48 when the second face 34.2 is substantially horizontal and oriented upwards. Of course, the invention is not limited to this solution for applying a calibrated force on the control probe 34 in the direction of the element to be controlled 40. Other mechanical systems making it possible to ensure constant pressure on the control probe 34 could be used.

[0058] The combination of the calibrated shim(s) and the calibrated force makes it possible to control the thickness of the glue 42.1.

[0059] According to one configuration, the polymerization step is carried out under a controlled atmosphere configured to optimize the polymerization of the glue 42.1. This controlled atmosphere has an optimal controlled temperature for the polymerization of the glue 42.1. Thus, during the polymerization step, the glue 42.1 is maintained at a stable temperature having a value adapted to the glue 42.1 to optimize the polymerization process. The controlled temperature varies depending on the material of the glue 42.1.

[0060] According to one configuration, the regulated atmosphere has a regulated pressure or other regulated characteristics.

[0061] The regulated atmosphere is maintained for a determined duration adapted to the glue 42.1 so that the latter is hardened or completely polymerized.

[0062] According to a configuration visible in [Fig.2], [Fig.4] and part (F) of [Fig.8], to obtain a regulated atmosphere, the control probe 34 is positioned in an enclosure 52 containing the regulated atmosphere during at least part of the polymerization step. According to one embodiment, the enclosure 52 comprises a face, pressed against the surface S of the element to be controlled 40, which has an opening 52.1 to allow the passage of the control probe 34.

[0063] According to an embodiment visible in [Fig.4] and part (G) of [Fig.8], at least one heating system 54 is provided for heating the glue 42.1 and / or the regulated atmosphere in which the glue 42.1 is positioned. According to an arrangement visible in [Fig.4], the heating system is positioned at a distance from the control probe 34, outside the enclosure 52. According to this arrangement, an air flow generator 56 is provided for blowing the air heated by the heating system 54 towards the enclosure 52.

[0064] According to another arrangement, the heating system 54 is positioned as close as possible to the glue 42.1 on at least part of the periphery of the control probe 34.

[0065] In addition to the heating system 54, at least one temperature sensor 58, such as a thermocouple for example, is configured to measure the temperature of the glue 42 and / or of the regulated atmosphere in which the glue 42.1 is positioned to enable the heating system 54 to be controlled so that the glue 42.1 and / or the regulated atmosphere in which the glue 42.1 is positioned has(have) a temperature substantially equal to a set value making it possible to obtain optimal polymerization of the glue 42.1. Thus, the combination of the heating system 54 and the temperature sensor 58 makes it possible to obtain a regulated temperature at the level of the glue 42.1 or near the latter.

[0066] According to one operating mode, the step of positioning the control probe 34 according to the given position and orientation consists of making at least one marking 60 on the surface S of the element to be controlled 40, as illustrated in part (A) of [Fig.8], and positioning the control probe 34 relative to the marking 60.

[0067] According to another operating mode visible in figures 6, 7 and parts (E) and (D) of [Fig.8], during the positioning step, the control probe 34 is positioned in a positioning tool 62 itself positioned relative to the marking 60 in order to position the control probe 34 according to the given position and orientation.

[0068] According to one embodiment, the positioning tool 62 comprises a body 64 which has first and second opposite faces 64.1, 64.2 as well as a housing 66, configured to house the control probe 34, which opens at the first and second faces 64.1, 64.2 and has a cross-section (in a plane parallel to the first or second face 64.1, 64.2) substantially identical to that of the control probe 34. Thus, when the control probe 34 is positioned in the housing 66, it is perfectly immobilized relative to the positioning tool 62 in a plane parallel to the first or second face 64.1, 64.2. Thanks to its polarization, the control probe 34 is immobilized relative to the positioning tool in a single orientation.Therefore, when the positioning tool 62 is correctly positioned relative to the marking 60 located on the surface S of the element to be checked 40, the control probe 34 positioned in the positioning tool 62 is positioned according to the given position and orientation.

[0069] The body 64 may be metallic, plastic or composite material.

[0070] According to one embodiment, the positioning tool 62 comprises a system heating system 54 positioned close to the first face 64.1 of the body 64 which is pressed against the surface S of the element to be controlled 40 in operation, preferably over at least part of the periphery of the housing 66. Thus, the heating system 54 is positioned as close as possible to the glue 42.1, allowing it to be heated by thermal diffusion in an optimal manner.

[0071] According to one arrangement, the temperature sensor 58 is positioned in the positioning tool 62 near the first face 64.1 of the body 64 to reliably measure the temperature of the glue 42.1.

[0072] According to one embodiment, the positioning tool 62 comprises at least one calibrated shim 46 connected to the body 64 and configured to be interposed between the control probe 34 and the element to be controlled 40. According to one arrangement, the positioning tool 62 comprises at least two wires substantially parallel to each other, each forming a calibrated shim 46, connected to the body 64, passing through the housing 66 and positioned at the first face 64.1 of the body 64.

[0073] According to one embodiment, a holding and polymerization equipment comprises at least one positioning tool 62 as well as possibly at least one enclosure 52 and / or at least one pressure system 50. This holding and polymerization equipment can be used to implement a method for placing a control probe 34. The enclosure 52 is sized to house the positioning tool 62 in which the control probe 34 is positioned.

[0074] According to an operating mode visible in [Fig.l], this installation process comprises: a. a step of affixing at least one marking 60 on the surface S of the element to be checked 40 as illustrated in part (A) of [Fig.8], said marking 60 being positioned as a function of the given position and orientation of the control probe 34, b. a step of applying the glue 42.1 by gluing an area of ​​the surface S of the element to be controlled 40, as illustrated in part (B) of [Fig.8], and the first face 34.1 of the control probe 34, as illustrated in part (C) of [Fig.8], c. a step of positioning the control probe 34 in the positioning tool 62 positioned according to the marking 60 on the surface S, as illustrated in FIGS. 6, 7 and parts (D) and (E) of [Fig.8], d. a step of positioning the pressure system 50 configured to exert a calibrated force on the control probe 34, as illustrated in [Fig.5], e. a step of placing the enclosure 52 so that it covers the control probe 34, as illustrated in [Fig.4] and part (F) of [Fig.8], f. a polymerization step under a controlled atmosphere and for a given duration, as illustrated in figure (G) of [Fig.8].

[0075] Whatever the operating mode, the installation process makes it possible to obtain an optimal glue thickness of 42.1 and polymerization.

[0076] This process also makes it possible to simplify the installation of the control probe and to optimize the installation time.

Claims

Claims

1. Method for placing a control probe (34) on a surface (S) of an element to be controlled (40), the control probe (34) being connected to the element to be controlled (40) by a coupling material (42) in the form of an adhesive (42.1) configured to occupy a first state in which the adhesive (42.1) can be applied and a second state, after a polymerization phase, in which the adhesive (42.1) connects the control probe (34) and the element to be controlled (40) and has a thickness substantially equal to a coupling value to obtain an optimal coupling between the control probe (34) and the element to be controlled (40); the placing method comprising a step of applying the adhesive (42.1), a step of positioning the control probe (34) relative to the element to be controlled (40) and a step of polymerizing the adhesive (42.1); characterized in that the installation method comprises a step of positioning at least one calibrated shim (46) inserted between the control probe (34) and the element to be controlled (40) at least before the polymerization step, each calibrated shim (46) having a thickness substantially equal to the optimal value of the thickness of the glue (42.1).

2. Method for installing a control probe (34) according to the preceding claim, characterized in that the step of positioning at least one calibrated shim (46) consists of inserting, between the control probe (34) and the element to be controlled (40), two spaced and substantially parallel wires which each have a diameter equal to the optimal value of the thickness of the glue (42.1).

3. Method for installing a control probe (34) according to one of the preceding claims, characterized in that each calibrated shim (46) has a thickness of between 100 and 200 pm, and preferably equal to approximately 150 pm with a tolerance of + / - 10%.

4. Method for placing a control probe (34) according to one of the preceding claims, characterized in that, during at least part of the polymerization step, a calibrated force (48) is applied to the control probe (34) in the direction of the element to be controlled (40) so that each calibrated shim (46) is simultaneously in contact with the element to be controlled (40) and the control probe (34).

5. Method for placing a control probe (34) according to one of the preceding claims, characterized in that the polymerization step- The production is carried out under a regulated atmosphere.

6. Method for installing a control probe (34) according to the preceding claim, characterized in that the regulated atmosphere has an optimal regulated temperature for the polymerization step of the glue (42.1).

7. Method for placing a control probe (34) according to one of the preceding claims, characterized in that the control probe (34) is positioned in an enclosure (52) containing a regulated atmosphere during at least part of the polymerization step.

8. Equipment for implementing a method for installing a control probe (34) according to one of the preceding claims, characterized in that the equipment comprises a positioning tool (62) which comprises a housing (66) configured to house a control probe (34) as well as at least one calibrated shim (46), connected to the positioning tool (62), configured to be inserted between the control probe (34) and the element to be controlled (40).

9. Equipment according to the preceding claim, characterized in that the positioning tool (62) comprises a body (64) which has first and second opposite faces (64.1, 64.2), the housing (66) opening at the level of the first and second faces (64.1, 64.2) and having a cross section substantially identical to that of the control probe (34).

10. Equipment according to the preceding claim, characterized in that the positioning tool (62) comprises at least two spaced and substantially parallel wires, each forming a calibrated shim (46), connected to the body (64), passing through the housing (66) and positioned at the level of the first face (64.1) of the body (64).

11. Equipment according to one of claims 8 to 10, characterized in that the equipment comprises a pressure system (50) configured to apply a calibrated force (48) on the control probe (34) in the direction of the element to be controlled (40).

12. Equipment according to the preceding claim characterized in that the pressure system (50) comprises at least one object of calibrated mass (50.1) positioned on the control probe (34).

13. Equipment according to one of claims 8 to 12, characterized in that the equipment comprises at least one heating system (54) for heating the glue (42.1) and / or a regulated atmosphere in which the glue (42.1) is positioned.

14. Equipment according to claims 9 and 13, characterized in that the heating system (54) is positioned in the body (64), close to the first face (64.1) of the body (64) configured to be oriented towards the element to be controlled (40) in operation.

15. Equipment according to one of claims 13 to 14, characterized in that the equipment comprises at least one temperature sensor (58) configured to measure the temperature of the glue (42) and / or of a regulated atmosphere in which the glue (42.1) is positioned in order to control the heating system (54).

16. Equipment according to claims 14 and 15, characterized in that the temperature sensor (58) is positioned in the positioning tool (62), close to the first face (64.1) of the body (64).

17. Equipment according to one of claims 8 to 16, characterized in that the equipment comprises at least one enclosure (52) sized to house the positioning tool (62) in which the control probe (34) is positioned.

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