Positioning and / or holding system, and method for implementing such a system

Abstract

The invention relates to a positioning and / or holding system (10) comprising: - a body (11) provided with at least one through-hole (12); and - at least one attachment device (13) comprising: - a pin (14) inserted into the through-hole (12) and comprising at least one threaded intermediate section (18) and a threaded end (23), which is intended to be screwed partially into a prevailing torque nut (24) floatingly mounted on a structural element (25); and - a locknut (28) mounted on the threaded intermediate section (18) of the pin (14), such that tightening the locknut (28) against the body (11) is capable of bringing about an axial movement of the pin (14) in order to apply a force along an axis of the pin (14) so as to press the prevailing torque nut (24) against the structural element (25)

Description

DESCRIPTION TITLE: POSITIONING AND / OR MAINTAINING SYSTEM AND METHOD FOR IMPLEMENTING SUCH A SYSTEM

[0001] The present invention relates to a positioning and / or holding system, in particular for a tool, such as a fixing device on a floating self-locking nut.

[0002] The invention finds a particularly advantageous, but not limiting, application in the field of aeronautics, in particular for the positioning of equipment supports during an assembly phase of an aircraft engine.

[0003] Due to the increasing assembly rates of aircraft engines, it is necessary to reduce the assembly cycle time of parts by pre-mounting equipment brackets on an engine casing. Equipment, such as a fuel filter or a starter, is subsequently mounted on the engine casing via the equipment brackets.

[0004] In order to carry out the pre-assembly of the equipment supports on the engine casing, it is known to use a mounting template representative of the equipment fixing interfaces, i.e. the mounting template has fixing devices located in areas corresponding to the positioning of the equipment fixing interfaces.

[0005] Such a mounting jig is manually fixed by means of fixing devices on equipment supports which can be moved in fixing areas of the aircraft casing. Once the mounting jig is fixed to the equipment supports, the positioning of the latter is fixed by screwing the equipment supports onto the engine casing.

[0006] The mounting jig can then be disassembled and the equipment brackets are then pre-positioned correctly at the equipment mounting interfaces.

[0007] Such pre-positioning of equipment supports makes it possible to carry out assembly of equipment on a site different from that where an initial phase of assembly of the engine without the equipment is carried out.

[0008] Figure 1 is a perspective view of an engine housing having mounting jigs allowing pre-positioning of equipment supports.

[0009] More particularly, figure 1 illustrates a positioning of several mounting templates 1 on a casing 2 of an aircraft engine.

[0010] Each mounting template 1 comprises fixing devices 3 cooperating with equipment supports 4.

[0011] Once the equipment supports 4 are fixed on the casing 2, the equipment supports 4 are arranged in a configuration corresponding to the equipment fixing interfaces, not shown in FIG. 1, to be subsequently mounted on the casing 2.

[0012] The assembly templates 1 can then be dismantled.

[0013] However, in the case where the equipment support 4 includes a self-locking nut mounted floating inside a cage, problems may arise in fixing the mounting template 1 which may subsequently lead to difficulties in mounting the equipment.

[0014] It should be remembered that a self-locking nut has standard threads and then deformed threads to hold a screw or stud and prevent the screw or stud from loosening after assembly.

[0015] Figure 2 is a longitudinal sectional view of a device for fixing a mounting jig according to the state of the art.

[0016] More particularly, Figure 2 shows a mounting jig 1 provided with a fixing device 3 comprising a screw 5 cooperating with a self-locking nut 6 carried by an equipment support 4.

[0017] The self-locking nut 6 is mounted floating inside a cage 7.

[0018] In the case where the fixing device 3 comprises a screw 5 that is too short, there is a risk that the latter will not be able to engage with the self-locking nut 6, in particular when the play between the self-locking nut 6 and the equipment support 4 is maximum, due to gravity causing the self-locking nut 6 to rest on a bottom of the cage 7.

[0019] Furthermore, in the case where the fixing device 3 has a screw 5 that is too long, there is a risk that the latter will be screwed up to the portion of the self-locking nut 6 having the deformed threads. This is likely to damage the self-locking nut 6 which will no longer be able to properly perform its anti-loosening function when it is used with the fixing members of the equipment.

[0020] Furthermore, in the case where the tightening of a screw 5 that is too long is not carried out over its entirety, the self-locking nut 6 is not correctly pressed against the equipment support 4, which can cause poor positioning of the equipment support 4 on the aircraft casing and therefore subsequent incorrect assembly of the corresponding equipment.

[0021] The invention aims to effectively remedy the aforementioned drawbacks by proposing a positioning and / or holding system comprising: - a body provided with at least one through hole, and - at least one fixing device comprising: - a stud inserted inside the through hole and comprising at least one threaded intermediate section and one threaded end, intended to be partially screwed inside a self-locking nut mounted floating on a structural element, and - a locknut mounted on the threaded intermediate section of the stud.

[0022] According to the invention, tightening the locknut against the body is capable of causing an axial displacement of the stud to apply a force along an axis of the stud in order to press the self-locking nut against the structural element.

[0023] The invention thus makes it possible to guarantee that the floating self-locking nut is pressed against the structural element and therefore that an equipment support is correctly positioned.

[0024] The invention also makes it possible to avoid damage to the self-locking nut, since the lock nut, which takes up the mounting play of the self-locking nut inside a cage, allows the stud to be screwed only onto the standard threads of the self-locking nut.

[0025] In addition, the assembly thus constituted forms a captive assembly that is easy to handle.

[0026] According to different characteristics of the invention which may be considered individually or in combination: - the stud has a collar arranged inside a housing made in the body; - the collar has a diameter greater than the diameter of the passage hole; - the housing has an axial height capable of allowing axial movement of the collar inside the housing when the locknut is tightened; - the stud has a stud head with a knurled outer periphery; - the lock nut has a knurled external periphery; - the stud comprises a first centering section, in particular arranged inside the through hole, and a second centering section, in particular intended to be arranged inside a fixing hole made in the structural element; and - the body has a holding area intended to hold a part.

[0027] The invention also relates to an assembly comprising: - a holding and / or positioning system as previously defined, and - a structural element carrying a self-locking nut mounted floating inside a nut cage, - the threaded end of the stud being partially screwed inside the self-locking nut of the structural element, and - the locknut being tightened against the body of the holding and / or positioning system to apply a force along an axis of the stud allowing the self-locking nut to be pressed against the structural element.

[0028] The invention further relates to a method for implementing a positioning or holding system as previously defined intended to cooperate with a structural element carrying a self-locking nut mounted floating inside a nut cage, comprising at least: a partial screwing step, during which the threaded end of the stud is partially screwed inside the self-locking nut of the structural element, then a tightening step, during which the locknut is tightened against the body of the positioning and / or holding system to apply a force along an axis of the stud making it possible to press the self-locking nut against the structural element.

[0029] The present invention will be better understood and other characteristics and advantages will become apparent upon reading the detailed description which follows, comprising embodiments given for illustrative purposes with reference to the appended figures, presented as non-limiting examples, which may serve to complete the understanding of the present invention and the description of its embodiment and, where appropriate, contribute to its definition, in which:

[0030] [Fig. 1] Figure 1 is a perspective view of an engine housing having mounting jigs allowing pre-positioning of equipment supports;

[0031] [Fig. 2] Figure 2 is a longitudinal sectional view of a device for fixing a mounting jig according to the state of the art; [Fig. 3] Figure 3 is a perspective view of a positioning and / or holding system according to the present invention;

[0032] [Fig. 4a] [Fig. 4b] Figures 4a and 4b are longitudinal sectional views illustrating an operation of the positioning and / or holding system according to the present invention; and

[0033] [Fig. 5] Figure 5 is a perspective view of another embodiment of the positioning and / or holding system according to the invention.

[0034] It should be noted that, in Figures 3 to 5, the structural and / or functional elements common to the different embodiments may have the same references. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

[0035] Figure 3 is a perspective view of a positioning and / or holding system 10 according to the present invention. The system 10 is intended to be mounted on a structural element 25 which may be, for example, an equipment support in the case where a body 11 of the system 11 takes the form of a mounting jig.

[0036] The structural element 25 visible in Figure 4a comprises a self-locking nut 24, which may comprise standard threads, i.e. non-deformed threads, and deformed threads, in particular located after the standard threads. The self-locking nut 24 is mounted floating inside a nut cage 26.

[0037] More specifically, the system 10 comprises the body 11 and at least one fixing device 13 comprising a stud 14 and a locknut 28, and at least one through hole 12, capable of receiving the stud 14. The body 11 has the shape of a thin rectangular plate provided with four fixing devices 13 each arranged at a corner of the plate. Of course, the plate may have another geometric shape. Furthermore, the number and arrangement of the fixing devices 13 may vary depending on the configuration of the fixing interfaces of a piece of equipment.

[0038] The stud 14 is able to be inserted inside the through hole 12 and the lock nut 28 is able to be screwed onto the stud 14. The stud 14 may comprise a stud head 17 and a threaded end 23. The stud head 17 has an external diameter greater than an internal diameter of the lock nut 28 screwed onto the stud 14. The stud head 17 has for example a cylindrical shape having a diameter greater than that of the threaded portions of the stud 14. The lock nut 28 may have a housing open on the side of the stud head 17 and intended to receive at least in part the stud head 17. The stud head 17 is fixed relative to the shank of the stud 14. The stud head 17 may have a knurled external periphery. Such a configuration makes it easier to manually screw and unscrew the stud 14 by an operator.

[0039] Furthermore, the threaded end 23 of the stud 14 is intended to be partially screwed inside the self-locking nut 24 of the structural element 25.

[0040] The stud 14 may also include an intermediate threaded section 18.

[0041] The stud 14 may also comprise a first centering section 19, in particular arranged inside the passage hole 12 of the stud 14, and a second centering section 20, in particular intended to be arranged inside a fixing hole 32 made in the structural element 25.

[0042] The first centering section 19 and the second centering section 20 are preferably smooth sections. The first centering section 19 and the second centering section 20 have diameters substantially equal to the passage hole 12 of the stud 14 and to the fixing hole 32 of the structural element 25, respectively.

[0043] The stud 14 may also include a collar 29, in particular arranged inside a housing 31 made in the body 11. The collar 29 may have a diameter greater than a diameter of the passage hole 12 of the stud 14. The stud head 17 and the collar 29 make it possible to obtain a captive "body-stud-locknut" assembly during handling.

[0044] Furthermore, the housing 31 made in the body 11 may have an axial height H, measured along an axis of the stud 14, capable of allowing axial movement of the collar 29 inside the housing 31 when the locknut 28 is tightened, as shown in FIG. 4b.

[0045] Furthermore, the locknut 28 can be mounted on the threaded intermediate section 18 of the stud 14, so that tightening the locknut 28 against the body 11 is capable of causing an axial movement of the stud 14 to apply a force, along the axis of the stud 14, making it possible to press the self-locking nut 24 against the structural element 25.

[0046] In particular, the lock nut 28 may have a knurled external periphery. Such a configuration makes it easier for the operator to manually screw and unscrew the stud 14.

[0047] The present invention also relates to a method for implementing the positioning and / or holding system 10 intended to cooperate with the structural element 25 carrying the self-locking nut 24 mounted floating inside the nut cage 26.

[0048] The implementation method comprises a positioning step, during which the body 11 of the positioning and / or holding system 10 is pressed against the structural element 25.

[0049] Consequently, the implementation method comprises a partial screwing step, during which the threaded end 23 of the stud 14 is partially screwed inside the self-locking nut 24 of the structural element 25.

[0050] As illustrated in Figure 4a, the screwing of the stud 14 is carried out manually by the operator, following an arrow F1, until the operator feels a resistive torque, which means that the threaded end 23 has reached the deformed threads of the self-locking nut 24. The operator then stops screwing the stud 14.

[0051] The method further comprises a tightening step, during which the lock nut 28 is tightened against the body 11 of the system. positioning and / or holding 10 to apply a force along the axis of the stud 14 allowing the self-locking nut 24 to be pressed against the structural element 25.

[0052] As illustrated in Figure 4b, the force of pressing the lock nut 28 against the body 11, along an arrow F2, causes an axial displacement of the stud 14, along an arrow F3, making it possible to press the self-locking nut 24 against the structural element 25.

[0053] In the embodiment of Figure 5, the body 11 comprises a holding zone 33 for a part 34, in particular an aircraft part 34, such as a conduit, in particular an oil recovery conduit, or alternatively a fuel conduit or any other type of conduit that can be used inside an aircraft engine.

[0054] In this case, the holding zone 33 comprises an opening in which the part 34 is wedged. The holding zone 33 may comprise position indexing elements, such as indexing studs, edges, indexing tabs or any other indexing element making it possible to guarantee correct positioning of the part 34 relative to a reference element, such as a casing, during assembly.

[0055] Of course, the various features, variants and / or embodiments of the present invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive.

[0056] Furthermore, the invention is not limited to the embodiments described above and provided solely by way of example. It encompasses various modifications, alternative forms and other variations that may be envisaged by those skilled in the art within the scope of the present invention and in particular all combinations of the different modes of operation described above, which may be taken separately or in combination.

Claims

CLAIMS 1. Positioning and / or holding system (10) characterized in that it comprises: a body (11) provided with at least one through hole (12), and at least one fixing device (13) comprising: a stud (14) inserted inside the through hole (12) and comprising at least one threaded intermediate section (18) and one threaded end (23), intended to be partially screwed inside a self-locking nut (24) mounted floating on a structural element (25), said stud (14) comprising a stud head (17) and a collar (29) arranged inside a housing (31) made in the body (11), the collar (29) having a diameter greater than a diameter of the through hole (12), and a locknut (28) mounted on the threaded intermediate section (18) of the stud (14),such that tightening the locknut (28) against the body (11) is capable of causing an axial displacement of the stud (14) to apply a force along an axis of the stud (14) in order to press the self-locking nut (24) against the structural element (25)., 2. Positioning and / or holding system (10) according to claim 1, characterized in that the housing (31) has an axial height (H) capable of allowing axial movement of the collar (29) inside the housing (31) when tightening the locknut (28).

3. Positioning and / or holding system (10) according to any one of the preceding claims, characterized in that the stud head (17) has a knurled external periphery.

4. Positioning and / or holding system (10) according to any one of the preceding claims, characterized in that the lock nut (28) has a knurled external periphery.

5. Positioning and / or holding system (10) according to any one of the preceding claims, characterized in that the stud (14) comprises a first centering section (19), in particular arranged inside the passage hole (12), and a second centering section (20), in particular intended to be arranged inside a fixing hole (32) made in the structural element (25).

6. Positioning and / or holding system (10) according to any one of the preceding claims, characterized in that the body (11) comprises a holding zone (33), intended to hold a part (34).

7. Assembly characterized in that it comprises: a holding and / or positioning system (10) according to any one of the preceding claims, and a structural element (25) carrying a self-locking nut (24) mounted floating inside a nut cage (26), the threaded end (23) of the stud (14) being partially screwed inside the self-locking nut (24) of the structural element (25), and the lock nut (28) being tightened against the body (11) of the holding and / or positioning system (10) to apply a force along an axis of the stud (14) making it possible to press the self-locking nut (24) against the structural element (25).

8. Method for implementing a positioning and / or holding system (10) according to any one of claims 1 to 6 intended to cooperate with a structural element (25) carrying a self-locking nut (24) mounted floating inside a nut cage (26), characterized in that the implementation method comprises at least: a partial screwing step, during which the threaded end (23) of the stud (14) is partially screwed inside the self-locking nut (24) of the structural element (25), and a tightening step, during which the lock nut (28) is tightened against the body (11) of the positioning and / or holding system (10) to apply a force along an axis of the stud (14) allowing the self-locking nut (24) to be pressed against the structural element (25).

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