Tool for creating an impression of the external circumference of a bore in a part and method for creating an associated impression

Abstract

Tool for making an impression of the outer circumference (7) of a bore (8a) of a part (6), comprising: a shaft (9) comprising a first portion (11) having an outer surface (11a) configured to come axially into contact with the bore (8a) of the part (6), a head (10) comprising a radial portion (13) removably connected to a second portion (12) of the shaft (9) extending from the first portion (11), and an axial portion (14) extending from the radial portion (13) and comprising a bearing surface (15) configured to come into contact with the part (6) around the outer circumference (7) of the bore (8a) when the shaft (9) is mounted in the bore (8a) of the part (6), an annular radial space (16) formed between the axial portion (14) of the head (10) and the shaft (9), a feed channel (17) passing through the head (10) and opening onto the annular radial space (16), and a vent passing through the head and opening onto the annular radial space.Figure for the abbreviation: Fig 2.

Description

Title of the invention: Tool for making an impression of the external circumference of a bore in a part and method for making an associated impression technical field

[0001] The present invention relates to the characterization of non-conformities, marks or indications on the external perimeter of a bore of an aircraft turbomachine part, in particular of a fastening assembly comprising a nut.

[0002] More specifically, the invention relates to a tool for making an impression of the external circumference of a bore of a part, a method for making an impression of the external circumference of a bore of a part as well as a method for measuring non-conformities, marks or indications on the external circumference of a bore of a part. Previous techniques

[0003] A turboprop engine consists of a turbomachine and a propeller. Conventionally, the propeller is fixed to a propeller shaft by means of a mounting assembly.

[0004] As shown in [Fig. 1], the fastening assembly 1 comprises, for example, a first flange 2 connected to the propeller shaft, a second flange 3 connected to the propeller, and a plurality of bolts 4 distributed around the periphery of the flanges. The screw 4a of each bolt 4 passes through a first bore 2a of the first flange 2 and a second bore 3a of the second flange 3. The nut 4b of the bolts 4 screwed onto the screw 4a holds the first and second flanges 2, 3 together.

[0005] During tightening and loosening, the nut 4b of the bolts 4 causes scratches on the outer perimeter of the first flange 2 of the propeller shaft.

[0006] In order to guarantee the seaworthiness of the propeller shaft, it is crucial to characterize and evaluate these damages accurately and reliably by measuring their depths, widths and angular sectors.

[0007] To achieve this, optical or mechanical measurement systems exist that can be used directly on the part. However, the use of these measurement systems can prove complex under operational conditions. Access to the part is difficult or even impossible when the part is mounted on the aircraft, and the time required to remove the engine to perform the measurement in the laboratory is significant and costly.

[0008] A known solution consists of making an impression of the area to be characterized and taking measurements on this impression. The paste used to take the impression is relatively liquid during application and must be applied to the area during a few minutes before it dries and solidifies. However, the area to be measured is vertical, which complicates taking the impression and causes the paste to drip.

[0009] Moreover, the use of such an impression paste makes each impression unique, which complicates the measurement of the latter in the laboratory. Description of the invention

[0010] The present invention therefore aims to overcome the aforementioned drawbacks and to provide a solution for characterizing simply, reliably and cheaply the non-conformities, marks or indications which appear on the external perimeter of a bore of a part, in particular of a part of a fastening assembly subject to the stresses of a clamping element such as a nut.

[0011] The present invention relates to a tool for making an impression of the outer circumference of a bore in a part, comprising:

[0012] an axis comprising a first portion having an outer surface configured to come axially into contact with the bore of the part,

[0013] a head comprising a radial portion removably connected to a second portion of the shaft extending from the first portion, and an axial portion extending from the radial portion having a bearing surface configured to come into contact with the part around the outer periphery of the bore when the shaft is mounted in the bore of the part,

[0014] an annular radial space formed between the axial portion of the head and the axis,

[0015] a feed channel passing through the head and opening into the annular radial space, and

[0016] a vent passing through the head and opening onto the annular radial space.

[0017] Such a tool makes it easier and more reliable to take impressions around the perimeter external, especially vertical, of a bore in a part, so that non-conformities, marks or indications of that bore become easily and quickly measurable at negligible cost.

[0018] The axis allows a certain seal between the head and the bore, and more particularly between the annular chamber and the bore, so that the material to be replicated is contained in the space or radial annular chamber without filling the bore.

[0019] Preferably, the second portion of the axis is connected to the center of the radial portion of the head.

[0020] Preferably, the axis passes through the radial portion of the head.

[0021] Advantageously, the second portion of the axis can pass through the radial portion of the head.

[0022] Advantageously, the second portion of the axis may include at least one shoulder bearing against the radial portion of the head.

[0023] Preferably, the feed channel is positioned in a lower half of the head and the vent is positioned in an upper half of the head opposite the lower half, preferably the feed channel and the vent are positioned on the axial portion.

[0024] Advantageously, the tool may include means for retaining the head and the axis on the workpiece.

[0025] In one embodiment, the tool may include first and second nuts disposed respectively on either side of the head and adapted to cooperate with at least one thread disposed on the axis to maintain the axis in the bore and the bearing surface of the axial portion of the head in contact with the outer perimeter of the bore of the part.

[0026] The invention also relates to a method for making an impression of the outer perimeter of a bore in a part, comprising the following steps:

[0027] a) the positioning of a tool as described above on the part, the first portion of the shaft being inserted into the bore of the part, the outer surface of the first portion of the shaft coming axially into contact with the bore of the part, the head and the second portion of the shaft being connected before or after the insertion of the first portion of the shaft into the bore of the part, and the bearing surface of the axial portion of the head coming into contact with the outer circumference of the bore,

[0028] b) the insertion of a replica material into the annular radial space via the feed channel,

[0029] c) the drying and solidification of the replica material, and

[0030] d) the removal of the tool from the part and the recovery of the impression obtained.

[0031] Preferably, in steps a), b) and c), the feed channel is positioned in a lower half directed downwards of the tool head and the vent is positioned in an opposite upper half directed upwards of the tool head, preferably the feed channel and the vent being positioned on the axial portion of the tool head.

[0032] The invention also relates to a method for measuring non-conformities, marks or indications on the external perimeter of a bore of a part, comprising making an impression according to the method for making an impression as described above and a step e) of measuring the impression obtained. Brief description of the drawings

[0033] The present invention will be better understood and other objects, advantages and features will become apparent from the detailed description that follows, including embodiments given by way of illustration only and made with reference to The attached drawings, presented as non-limiting examples, may serve to supplement the understanding of the invention and the explanation of its implementation and, where appropriate, contribute to its definition, on which:

[0034] [Fig. 1] illustrates a fastening assembly comprising first and second flanges assembled with bolts.

[0035] [Fig.2] is a cross-sectional view of a tool mounted on a workpiece for carrying out a imprint of the external circumference of a bore of the part according to an embodiment of the invention.

[0036] [Fig.3] is a cross-sectional view of a tool mounted on a workpiece for the realization of an impression of the outer perimeter of a bore of the part according to another embodiment of the invention.

[0037] [Fig.4] is a cross-sectional view of a tool mounted on a workpiece for the realization of an impression of the outer perimeter of a bore of the part according to another embodiment of the invention.

[0038] [Fig.5] is a perspective view of the tool illustrated in [Fig.4].

[0039] [Fig.6] is a perspective view of the head of the tool illustrated in [Fig.4] according to a method of embodiment of the invention.

[0040] [Fig.7] illustrates a method for making an impression of the outer perimeter of a boring of a part according to an embodiment of the invention.

[0041] It should be noted that, in the figures, structural and / or functional elements common to the different embodiments may have the same reference numerals. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0042] In the description of the invention that will be given, the expression "at least one" used shall be considered equivalent to the expression "one or more". Detailed description of at least one embodiment

[0043] Figure 2 illustrates a tool 5 according to a first embodiment of the invention, mounted on an aircraft turbomachine part. Tool 5 enables the creation of an impression E of the external circumference 7 of a bore or cylindrical opening 6a made on the flange 6.

[0044] In the illustrated example, the part is a flange 6 of a propeller shaft of an aircraft turbomachine such as a turboprop.

[0045] According to an alternative, the part can, for example, be a suspension ear, such as an engine suspension ear, an accessory gearbox suspension ear, or an equipment suspension ear.

[0046] The part can also be an equipment pad placed on an AGB or a pipe or harness support bump.

[0047] By external perimeter, we mean an area on the periphery of a bore, located on a face of the part on which the bore opens, said face passing through a plane substantially perpendicular to the longitudinal axis of the bore.

[0048] In the illustrated example, the cylindrical opening 6a leads to a first potentially damaged face 6b and to a second axially opposite face 6c of the flange 6.

[0049] The tool 5 is mounted on the flange 6 so as to be able to make an impression E of the external perimeter 7 of the cylindrical opening 6a, carried by the first face 6b of the flange 6.

[0050] As illustrated, the flange 6 may include a bushing 8, such as a centering bushing for a bolt, disposed inside the cylindrical opening 6a of the flange 6. The bushing 8 includes an outer surface 8b configured to come axially into contact with the cylindrical opening 6a of the flange 6, and a bore 8a radially opposite to the outer surface 8b.

[0051] In the illustrated example, the outer perimeter 7 of the cylindrical opening 6a carried by the first face 6b of the flange 6 also forms the outer perimeter of the bore 8a of the sleeve 8.

[0052] The tool 5 comprises an axis 9 and a head 10 connected in a removably manner.

[0053] The shaft 9 includes a first portion 11 intended to be mounted in the bore 8a of the sleeve 8, having an outer surface 1 configured to come axially into contact with the bore 8a of the sleeve 8 when the shaft 9 is mounted in the bore 8a of the sleeve 8.

[0054] In the illustrated example, when the axis 9 of the tool 5 is mounted in the bore 8a of the sleeve 8, the longitudinal axis of the axis 9 is common to the longitudinal axis of the cylindrical opening 6a of the flange 6 and to the longitudinal axis X of the bore 8a of the sleeve 8.

[0055] In an alternative embodiment, the outer surface 1 of the first portion 11 of the shaft 9 can, in the absence of the bushing 8, be configured to come axially directly into contact with the cylindrical opening 6a of the flange 6 when the shaft 9 is mounted on the flange 6.

[0056] The shaft 9 further comprises a second portion 12 extending axially from the first portion 11, configured to extend out of the bore 8a of the sleeve 8 and intended for the removable connection of the shaft 9 and the head 10.

[0057] The head 10 comprises a radial portion 13 and an axial portion 14 extending the radial portion 11.

[0058] In the illustrated example, the radial portion 13 is cylindrical and the axial portion 14 forms an annular shoulder.

[0059] In addition, the axial portion 14 extends perpendicularly to the radial portion 13.

[0060] The axial portion 14 of the head 10 has a bearing surface 15 configured to come into contact with the first face 6b of the flange 6, around the external circumference 7 of the cylindrical opening 6a, when the tool 5 is mounted on the flange 6.

[0061] In the illustrated example, the bearing surface 15 and the first face 6b of the flange 6 extend in a plane perpendicular to the longitudinal axis X of the cylindrical opening 6a of the flange 6.

[0062] An annular radial space 16 is provided between the axial portion 14 of the head and the axis 9 when the head 10 and the axis 9 are connected.

[0063] When the tool 5 is mounted on the flange 6, the annular radial space 16 is delimited by the outer perimeter 7 of the cylindrical opening 6a of the flange 6, the second portion 12 of the axis 9 and an inner surface 13a of the radial portion 13 of the head 10 and an inner surface 14a of the axial portion 14 of the head 10.

[0064] In addition, a feed channel 17 passes through the head 10 and opens onto the annular radial space 10, allowing material to be routed into the annular radial space 10 to form the impression E.

[0065] In the illustrated example, the feed channel 17 passes through the axial portion 14 of the head 10.

[0066] In addition, a vent 18, visible on [Fig.5], passes through the head 10 and opens onto the annular radial space 16. The vent allows the air present in the annular radial space 16 to be evacuated during its filling with the replica material.

[0067] The axis 9 allows the head 10 to be positioned and held in position, so that the head 10 is in planar contact with the first face of the flange 6, around the external circumference 7.

[0068] The axis 9 also prevents the replica material from entering the bore, thus limiting the formation of a bead of replica material on the impression E. This simplifies the measurement and limits the amount of replica material required.

[0069] The use of such a tool 5 makes it easier and more reliable to take an impression on the external perimeter 7, in particular vertical, of a bore, such as the cylindrical opening 6a of the flange 6.

[0070] The impression can be taken without the need to remove the turboprop.

[0071] The axis 9 centers the tool 5, and in particular the head 10, so that when the tool 5 is mounted on the flange 6, the bearing surface 15 of the radial portion 13 of the head 10 is parallel to the first face 6b of the flange 6 potentially damaged and bearing against it.

[0072] The diameter of the first portion 11 of the shaft 9 allows a tight fit for holding the tool 5 on the flange 6.

[0073] In addition, the tool 5 may include removable means for connecting the head 10 and the shaft 9.

[0074] Preferably, the second portion 12 of the axis 9 is connected to the center of the radial portion 13 of the head 10 in order to center the head 10 and adjust the contact between the bearing surface 15 of the head 10 and the area of ​​the first face 6b of the flange 6 located around the external perimeter 7 whose imprint E is to be made.

[0075] In order to facilitate the connection of the axis 9 and the head 10, the second portion 12 of the axis 9 can advantageously pass through the radial portion 13 of the head 10 by means of an orifice 19 provided in the center of the radial portion 13.

[0076] The second portion 12 of the axis 9 includes a first shoulder 20 bearing, when the axis 9 and the head 10 are connected, against the inner surface 13a of the radial portion 13 of the head 10 and forming a stop.

[0077] Preferably, the axis 9 includes a second shoulder 21, the cross-section of the axis 9 passing through the second shoulder 21 deviating from a cylindrical section so as to prevent the rotation of the axis 9 relative to the head 10. The cross-section of the axis 9 passing through the second shoulder is, for example, square, as illustrated in [Fig.6].

[0078] When the axis 9 and the head 10 are connected, the second shoulder 21 comes to rest against a complementary shoulder 22 of the radial portion 13 of the head 10.

[0079] Advantageously, the tool 5 includes means for retaining the head 10 and the shaft 9 on the flange 6.

[0080] With reference to [Fig.3], in a second embodiment, the tool 5 can, for example, include first and second nuts 23 and 24.

[0081] The first and second nuts 23 and 24 cooperate, respectively, with a first thread 25 formed on the first portion 11 of the shaft 9 and a second thread 26 formed on the second portion 12 of the shaft 9 arranged thus, respectively, on either side of the assembly formed by the head 10 and the flange 6.

[0082] Thanks to the first and second nuts 23 and 24, the shaft 9 is held in the bore 8a of the sleeve 8 of the flange 6 and the bearing surface 15 of the axial portion 14 of the head 10 is held in contact with the outer perimeter 7.

[0083] According to another embodiment, and with reference to figures 4, 5 and 6, the means for retaining the head 10 and the shaft 9 on the flange 6 may include first and second clamping flanges 27 and 28 held by a bolt incorporating a screw 29 and a nut 30.

[0084] Preferably, the first flange 27 and the head 10 are monobloc, the first flange 27 extending the bearing surface 15 of the axial portion 14.

[0085] The second flange 28 includes a bearing surface 31 coming into contact with the second face 6c of the flange 6.

[0086] The first and second clamping flanges 27 held by the bolt on the periphery of the flange 6 firmly hold the tool 5 on the flange 5 when making the imprint E.

[0087] In the illustrated example, the supply channel 17 and the vent 18 are positioned on the axial portion 14.

[0088] Preferably, the feed channel 17 is positioned in a lower half 10a of the head 10 which, when the tool 5 is mounted on the flange 6, is directed downwards towards the ground, and the vent 18 is positioned in an upper half 10b of the head 10, opposite the lower half which, when the tool 5 is mounted on the flange 6, is directed upwards.

[0089] The positioning of the vent 18 in overhang relative to the feed channel 17 optimizes the flow of the material to be replicated by avoiding drips out of the tool 5 as well as bubbles in the material to be replicated.

[0090] The tool 5 thus allows a homogeneous distribution on the external perimeter 7 of the cylindrical opening 6a of the flange 6.

[0091] Fig. 7 is a flowchart illustrating a method for measuring non-conformities, marks or indications on the external circumference 7 of the cylindrical opening 6a of the flange 6.

[0092] The measurement method comprises making an impression E of the outer perimeter 7 of the cylindrical opening 6a of the flange 6 according to the following steps:

[0093] a) the positioning of the tool 5 on the flange 6.

[0094] In step a), the first portion 11 of the shaft 9 is inserted into the bore 8a of the socket 8 so that the outer surface 1 of the first portion 11 of the axis 9 comes axially into contact with the bore 8a of the socket 8.

[0095] In the absence of the sleeve 8, the shaft 9 is directly inserted into contact with the cylindrical opening 6a of the flange 6.

[0096] The head 10 and the shaft 9 can be connected before the insertion of the first portion 11 of the shaft 9 into the bore 8a of the sleeve 8.

[0097] Alternatively, the head 10 and the shaft 9 can be connected after the insertion of the first portion 11 of the shaft 9 into the bore 8a of the sleeve 8.

[0098] When the head 10 is connected to the shaft 9 and the shaft 9 is mounted on the flange 6, the bearing surface 15 of the axial portion 14 of the head 10 comes into contact with the outer perimeter 7 of the cylindrical opening 6a of the flange 6.

[0099] b) the insertion of a replica material into the annular radial space 16 via the feed channel 17. The replica material is inserted until the annular radial space 16 is filled.

[0100] c) the drying and solidification of the replica material.

[0101] d) the removal of the tool 5 from the flange 6 and the recovery of the impression E obtained.

[0102] e) the measurement of the footprint E obtained.

[0103] The impression E obtained allows the external perimeter 7 of the cylindrical opening 6a of the flange 6 to be characterized by complementarity.

[0104] Tool 5 advantageously allows for the standardization of the obtained E impressions and facilitates their measurement. A large volume of E impressions can thus be easily characterized in a short time.

[0105] The tool 5 allows the external perimeter 7 to be measured using traditional laboratory measurement methods without accessibility constraints and allows the detection of shallow scratches, from 5 pm.

[0106] The head 10 and the axis 9 protect and hold the replica material in place during its drying.

[0107] Preferably, the feed channel 17 and the vent 18 are positioned on the axial portion 14 of the head 10 of the tool 5.

[0108] Preferably, in steps a), b) and c), the feed channel 17 is positioned in a lower half 10a directed downwards of the head 10 of the tool 5 and the vent 18 is positioned in an upper half 10b opposite and directed upwards of the head 10 of the tool 5.

[0109] The production of an impression E from the tool 5 can be applied to any part where it is necessary to take measurements around a bore, and in particular all bolt bearing faces.

[0110] In the illustrated example, the part is a flange 6.

[0111] In another embodiment, the part can be, for example, a clevis of a fastening assembly comprising a connecting rod and a clevis mounted on an axle and held by a nut.

Claims

Demands

1. A tool for making an impression (E) of the outer circumference (7) of a bore (6a) of an aircraft turbomachine part (6), comprising: a shaft (9) comprising a first portion (11) having an outer surface (1a) configured to come into axial contact with the bore (8a) of the part (6), a head (10) comprising a radial portion (13) removably connected to a second portion (12) of the shaft (9) extending from the first portion (11), and an axial portion (14) extending from the radial portion (13) and comprising a bearing surface (15) configured to come into contact with the part (6) around the outer circumference (7) of the bore (8a) when the shaft (9) is mounted in the bore (8a) of the part (6), an annular radial space (16) formed between the axial portion (14) of the head (10) and the axis (9), a feed channel (17) passing through the head (10) and opening onto the annular radial space (16),and a vent (18) passing through the head (10) and opening onto the annular radial space (16).

2. Tool according to claim 1, wherein the second portion (12) of the axis (9) is connected to the center of the radial portion (13) of the head (10).

3. Tool according to claim 1 or 2, wherein the second portion (12) of the axis (9) passes through the radial portion (13) of the head (10).

4. Tool according to any one of the preceding claims, wherein the axis (9) comprises at least one shoulder (20) bearing against the radial portion (13) of the head (10).

5. Tool according to any one of the preceding claims, wherein the feed channel (17) is positioned in a lower half (10a) of the head (10) and the vent (18) is positioned in an upper half (10b) of the head (10) opposite the lower half (10a), preferably the feed channel (17) and the vent (18) are positioned on the axial portion (14).

6. Tool according to any one of the preceding claims, comprising means for retaining the head (10) and the axis (9) on the part (10).

7. Tool according to claim 6, comprising first and second nuts (23, 24) disposed respectively on either side of the head (10) and adapted to cooperate with at least one thread (25, 26) disposed on the axis (9) to maintain the axis (9) in the bore (8a) and the bearing surface (15) of the axial portion (14) of the head (10) in contact with the outer perimeter (7) of the bore (8a) of the part (6).

8. A method for forming an impression (E) of the outer circumference (7) of a bore (8a) of an aircraft turbomachine component (6), comprising the following steps: a) positioning a tool (5) according to any one of the preceding claims on the component (6), the first portion (11) of the shaft (9) being inserted into the bore (8a) of the component (6), the outer surface (11a) of the first portion (11) of the shaft (9) coming axially into contact with the bore (8a) of the component (6), the head (10) and the second portion (12) of the shaft (9) being connected before or after the insertion of the first portion (11) of the shaft (9) into the bore (8a) of the component (6), and the bearing surface (15) of the axial portion (14) of the head (10) coming into contact of the outer periphery (7) of the bore (8a), b) the insertion of a replica material into the annular radial space (16) via the feed channel (17), c) the drying and solidification of the replica material,and d) the removal of the tool (5) from the part (6) and the retrieval of the resulting impression (E).

9. A method according to claim 8, wherein, in steps a), b) and c), the feed channel (17) is positioned in a lower half (10a) of the head (10) of the tool (5) directed downwards and the vent (18) is positioned in an opposite upper half (10b) of the head of the tool (5) directed upwards, preferably the feed channel (17) and the vent (18) being positioned on the axial portion (14) of the head (10) of the tool (5).

10. Method for measuring non-conformities, marks or indications on the external circumference (7) of a bore (8a) of a part (6) of an aircraft turbomachine, comprising making an impression (E) according to the method for making an impression (E) as defined in claim 8 or 9 and a step e) of measuring the impression (E) obtained.

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