Machine for referencing a lap joint and associated welding process

Abstract

Machine for referencing a lap joint and associated welding process. The invention relates to an automatic machine involving a press-fitted assembly having a free outer edge 1000 inscribed in a plane P1. The automatic means comprises: - a frame 310, - a stop 32 movable between a retraction position and a reference position in which the stop defines a reference plane P3, - a carriage 33 movable between a loading position and a working position, - a jig 34 for positioning and clamping the press-fitted assembly, - a universal joint 35 adapted to pre-position plane P1 parallel to plane P3. Alignment of planes P1 and P3 is obtained by automatic movement of the carriage by sliding and friction of the free outer edge 1000 on the stop 32. Abbreviated figure: Figure 4

Description

Title of the invention: Machine for referencing a lap joint and associated welding method technical field

[0001] The invention relates to an automatic means for mechanically referencing a planar entity relative to a planar stop, the planar entity having an axis. The stop optionally defines a reference point, the referencing enabling, in such a case, the alignment of the entity's axis with the reference point. The invention applies in particular to an assembly comprising a first and a second component, the second component being fitted into the first, the fitting defining a shoulder delimited by a lap joint and an edge, the assembly being intended to be welded along the edge. In such an application, the planar entity corresponds to the shoulder delimited by the lap joint and the weld edge. When both components are cylindrical, the axis of the planar entity corresponds to the axis of the fitting.

[0002] According to another aspect, the invention relates to an automatic method for referencing a planar entity with a planar stop, optionally including the alignment of an axis of the planar entity with the center of the stop. Such a method can advantageously be used to improve the welding conditions of an assembly formed by two fitted cylindrical components, the fitting defining a weld joint, the method using the automatic means according to the invention, the method typically employing a torch according to MIG / MAG technology. The invention, which allows referencing of the plane and the center of the joint prior to welding, has the beneficial effect of aligning the torch with the weld edge. Such a method is particularly useful for welding tubes and accessories used to guide the gases of an exhaust line of an internal combustion engine. Previous technique

[0003] Automatic workshop welding of an assembly consisting of two cylindrical components is commonly performed by fitting the two components together and positioning and clamping them on a jig. The fitted, positioned, and clamped assembly defines a lap joint. MIG / MAG technology can be used to perform the welding. For the needs of high-volume production, the positioned and clamped assembly can be oriented using an automatic positioner that moves angularly relative to the workshop. The positioner can be a rotator capable of rotating it around a working axis. The fitting defines a shoulder. The weld is internally delimited by a weld joint and externally by a weld edge. A MIG / MAG torch, feeding a welding wire, is mounted on a robotic arm. The torch at the end of the arm is programmed to direct the welding wire towards the weld edge. Automatic welding is performed by synchronizing the trajectories of the positioner and the robotic arm. The welding wire travels along the weld edge, and the weld consists of one or more beads, with or without overlap.

[0004] To make the welding repeatable in order to guarantee weld quality, it is necessary to control the alignment of the welding wire / electrode with the welding edge.

[0005] However, the lap joint may exhibit variations in position and orientation relative to the welding jig and therefore to the positioner. These variations result from the manufacturing conditions of the primary components and the sub-assemblies from which the first and second components forming the assembly are derived.

[0006] The first and second components may be tubular, and the seal may be inscribed in a plane. In such a case, after positioning and clamping, the fitting has an axis, and the seal has a center located at the intersection of the axis and the plane. Since both components are tubular, the seal delimits a fitting portion having two thicknesses and an overhanging portion having only one thickness.

[0007] A nominal assembly (in English: “master”) consisting of two components made to nominal specifications, themselves positioned and clamped on a template made according to a numerical definition, defines a theoretical fit and joint, themselves defining a theoretical axis, a theoretical plane and a theoretical center.

[0008] A typical assembly from a production batch exhibits geometric variations relative to the 'master', and the position of the current joint can be assessed by considering the positions of the current plane and the current center relative to the theoretical plane and the theoretical center. These relative positions can be further assessed by comparing the axial and radial positions of the current center relative to the theoretical center and the angular positions of the current plane relative to the theoretical plane.

[0009] These relative radial, axial and angular positions are the main factors contributing to the misalignment of the torch with the welding edge, the position of the torch at the end of the robot arm being sufficiently repeatable.

[0010] When the lap joints of a population of assemblies exhibit axial, radial, and angular relative positions at intervals that result in non-repeatable welding, it is known to use a method and means for realignment by vision. The means uses a light source, typically a laser, and a light sensor, typically a camera. The means is capable of determining the current relative positions of the joint, the determination being able to be carried out by vision of the joint before welding or during welding. A control means gives the robotic arm a Current realignment instruction based on the current relative position. Alignment between the torch and the joint is restored by the realignment instruction.

[0011] This first solution has the disadvantage of requiring an incident light source which may be unavailable, for example when the template, given its configuration, obstructs the path of the light.

[0012] When the clincher joints of a production batch have significant axial relative positions, the angular and radial relative positions being limited and without consequence for the welding, it is known to implement a second solution using a mechanical means to axially reference the joint / the weld edge.

[0013] The mechanical means comprises a jig, a carriage, a retractable stop, a reversible locking means, and an axial turner. The carriage is free to move translationally about the axis of the turner. The locking means allows the carriage to be immobilized relative to the frame, the axis of the mounting being substantially aligned with the axis of the turner. The retractable stop defines a line perpendicular to the direction of translation of the carriage. The shoulder and the stop are designed to achieve at least point contact.

[0014] The method comprises the operations of loading the assembly onto the jig, positioning the stop, moving the carriage until contact is made, immobilizing the carriage by locking it, and retracting the stop. The result of these operations is a reference positioning of the weld edge. The welding is performed by rotating the rotator and programming the torch position.

[0015] Since the torch is programmed axially relative to the reference position, a repeatable axial alignment of the current edge with the torch / welding wire / electrode follows.

[0016] This second solution, although easily automated, is no longer sufficient, particularly when the angular dispersion of the joint plane is significant; such dispersion leads, according to the second solution, to an axial beat during welding that is not tolerated, the axial beat being the cause of excessive weld penetration / perforation when the torch is directed towards the single thickness and insufficient penetration into the joint when the torch is directed towards the double thickness.

[0017] Thus, the two solutions known and described above do not give complete satisfaction.

[0018] The vision registration solution may be rendered unusable due to the configuration of the template which obstructs the path of light.

[0019] The mechanical axial referencing solution using a retractable stop may be rendered unusable by excessive angular dispersion of the joint plane due to downstream manufacturing steps, such dispersion resulting in axial runout Not tolerated by MIG / MAG technology.

[0020] It is well known that blocking the three rotations and three translations of a mechanical part is sufficient to impose a position and orientation upon it. Such a mechanical part, having a flat face, coupled to a flat stop via a rotating universal joint and a translating carriage, can occupy an equilibrium state characterized by alignment of the face and the stop. This equilibrium state is typically obtained by applying a force to the carriage transmitted to the part and by applying a counterforce to the part through the reaction of the stop to the force. Such an equilibrium position imposes a single orientation of the part relative to the stop, with all six degrees of freedom being blocked.Such an industrially advantageous referencing method raises the problem of possible butting of the flat face relative to the stop when an automatic movement / translation of the carriage is required to automate the referencing process. Summary of the invention

[0021] One of the aims of the invention is therefore to overcome the aforementioned problems.

[0022] To this end, the invention relates to an automatic machine for referencing a fitted assembly,

[0023] the handle assembly comprising:

[0024] - a first component having a first cylindrical tubular portion, the first cylindrical tubular portion having a free external edge which lies in a plane PI,

[0025] - a second component having a second cylindrical portion, said second The cylindrical portion being fitted into the first tubular cylindrical portion,

[0026] the automatic machine comprising:

[0027] - an automatic positioner comprising a chassis,

[0028] - an automatic retractable stop relative to the chassis, said stop being movable between a retraction position and a reference position, said stop defining, in the reference position, a repeatable reference plane P3 in position relative to the chassis,

[0029] - an automatic trolley that moves in translation relative to the chassis between a a rearward position and a working position, the direction of translation of the trolley being perpendicular to the reference plane P3,

[0030] - an automatic jig configured to position and clamp the fitted assembly,

[0031] - an automatic cardan joint connecting the jig to the carriage, comprising a first component pivoting about a substantially horizontal axis and comprising a return element, and a second pivoting member comprising a pre-positioning element, the return element and the pre-positioning element being capable of pre-orienting the PI plane of in a manner substantially parallel to plane P3 in the recoil position, the fitted assembly positioned and clamped in the jig occupying a first equilibrium state,

[0032] the cardan joint being configured so that the fitted assembly occupies a second equilibrium state in which planes PI and P3 coincide when the carriage is in the working position,

[0033] the second equilibrium state being obtained from the first equilibrium state by automatic movement of the carriage between the recoil position and the working position, by rotation of the pivoting members, and by sliding and friction of the free outer edge on the stop.

[0034] Specific features or embodiments, usable alone or in combination, are:

[0035] - the carriage includes a reversible locking means for the translation and an ac- tionneur, said reversible translation locking means blocking / unlocking the translation of the carriage relative to the chassis, the actuator moving the carriage between the reverse position and the working position, the first pivoting member includes a reversible angular locking means, the second pivoting member has an axis substantially perpendicular to the direction of translation of the carriage and includes a reversible angular locking means, the reversible angular locking means in combination automatically locking / unlocking the universal joint in rotation, and / or

[0036] - the template is mobile in rotation relative to the carriage around a point of the articulation point O of the cardan joint, the fitted assembly positioned and clamped in the jig defines a fitting axis Al, the axis Al being secant with the working plane PI at a working center Cl, the locus of points Cl being located in a sliding sphere centered on the articulation point O of the cardan joint and with a radius equal to five times the positioning error of point Cl relative to the jig, and / or

[0037] - the stop receives a surface treatment promoting the sliding of the outer edge free relative to the stop, and / or

[0038] - the stop receives a surface and / or core treatment promoting resistance to wear of the stop due to relative friction of the free outer edge, and / or

[0039] - the template defines a theoretical working axis Alth perpendicular to the plane P3 in the first equilibrium state, the stop defining in reference position a reference point C3 relative to the chassis, the angular return and angular pre-positioning elements being adjustable and pre-aligning the Alth axis with the reference point C3 in the first equilibrium state, and / or

[0040] - the cylindrical portion fitted into the assembly positioned and clamped in the template defines a repeatable axis Al relative to the template and aligned with the theoretical axis Alth; the assembly presents a second cylindrical portion extending beyond the first cylindrical portion with the indigo bushing fitted, the overhanging portion of the second cylindrical portion being guided by the stop in the reference position when the universal joint is unlocked, the assembly occupying the first state of equilibrium, and / or

[0041] - the angular pre-positioning element is an angular recall element.

[0042] According to a second aspect, the invention relates to an automatic method for referencing a fitted assembly by means of an automatic machine, the fitted assembly comprising: - a first tubular component having a first cylindrical portion, said first tubular cylindrical portion having a free external edge inscribed in a plane PI, - a second component having a second cylindrical portion, said second cylindrical portion being fitted into the first tubular cylindrical portion,

[0043] the method implementing: - the automatic machine, comprising: • an automatic positioner comprising a chassis, • an automatic retractable stop relative to the chassis, movable between a retracted position and a reference position, said stop defining, in the reference position, a repeatable reference plane P3 in position relative to the chassis, • an automatic trolley moving in translation relative to the chassis between a rearward position and a working position, the direction of translation of the trolley being perpendicular to the reference plane P3, • an automatic jig configured to position and clamp the fitted assembly, • an automatic universal joint connecting the jig to the carriage, comprising a first pivoting member around a substantially horizontal axis and comprising a return element, and a second pivoting member comprising a pre-positioning element, the return element and the pre-positioning element being capable of pre-orienting the plane PI substantially parallel to the plane P3 in the recoil position, the assembly fitted 1 positioned and clamped in the jig occupying a first state of equilibrium,

[0044] the cardan joint being configured so that the fitted assembly occupies a second equilibrium state in which planes PI and P3 coincide, when the carriage is in the working position,

[0045] the automatic process comprising the following cyclic steps: - to obtain the first state of equilibrium, - to reference the stop, - to obtain the second state of equilibrium,

[0046] the second equilibrium state being obtained from the first equilibrium state by automatic movement of the carriage between the recoil position and the working position, by rotation of the pivoting members and by sliding and friction of the free outer edge on the stop.

[0047] Specific features or embodiments, usable alone or in combination, are:

[0048] - the carriage includes a reversible translation locking means and an ac- tionneur, said reversible translation locking means blocking / unlocking the translation of the carriage relative to the chassis, the actuator moving the carriage between the reverse position and the working position, the first pivoting member includes a reversible angular locking means and the second pivoting member, which has an axis substantially perpendicular to the direction of translation of the carriage, also includes a reversible angular locking means, the reversible angular locking means in combination automatically blocking / unlocking the cardan joint in rotation, the method comprising an automatic loading step prior to the step of obtaining the first equilibrium state in which the carriage occupies the reverse position, the carriage is locked in translation by the means, the cardan joint is blocked in rotation by the means and the fitted assembly is positioned and clamped on the jig, and / or

[0049] - the carriage includes a reversible locking means for the translation and an ac- tionneur, said reversible translation locking means blocking / unlocking the translation of the carriage relative to the chassis, the actuator moving the carriage between the recoil position and the working position, wherein the first pivoting member comprises a reversible angular locking means and wherein the second pivoting member has an axis substantially perpendicular to the direction of translation of the carriage, further comprises a reversible angular locking means, the reversible angular locking means in combination automatically blocking / unlocking the universal joint in rotation, the method comprising a work engagement step subsequent to the second equilibrium state step in which the carriage occupies the working position, the carriage is locked in translation by the means, the universal joint is blocked in rotation by the means, the fitted assembly being positioned and clamped on the jig, and / or

[0050] - a pre-assembly step of the first and second components is carried out pre- lablement to the stage of obtaining the first equilibrium state, and / or

[0051] - the pre-assembly step is a crimping, in which the jig defines an axis theoretical Alth and in which the crimping is carried out by isostatic positioning of the component according to external bearing surfaces SI, the cylindrical portion fitted to the assembly after crimping defining a repeatable axis Al relative to the bearing surface SI, the repeatable axis Al being aligned with the theoretical axis Alth when the assembly is positioned and clamped on the jig according to the bearing surfaces SI, and / or

[0052] - the machine is a welding installation and a welding step is consecutive of the work commitment stage, and / or

[0053] - the welding installation includes a welding head defining an axis A4, in in which the stop in the reference position defines a center C3 and in which the positioner rotates the chassis around an axis A2 perpendicular to plane P3 and passing through the center C3, the welding step being carried out by aligning the axis A4 with planes PI and P3 coinciding and by rotating the chassis around the axis A2. Brief description of the drawings

[0054] The invention will be better understood upon reading the following description, given solely by way of example, and with reference to the figures in the appendix in which:

[0055] [Fig-1] shows a set with a crimped handle,

[0056] [Fig.2] shows a crimping means,

[0057] [Fig.3] shows a welding method,

[0058] [Fig.4] shows the welding means which is a means of referencing,

[0059] [Fig.5] shows an angular return element,

[0060] [Fig.6] shows a first state of equilibrium of a group, and

[0061] [Fig.7] shows welding conditions of the assembly. Description of the implementation methods

[0062] With reference to [Fig.1], and according to a preferred embodiment, an assembly 1 comprises a first tubular component 10 and a second component 11.

[0063] The first tubular component 10 has a first cylindrical portion 100 of revolution, said first cylindrical portion 100 having a substantially flat and circular fitting end 100a. The first tubular component 10 may also include a sleeve 101 mounted on the inner surface of the first cylindrical portion 100, said sleeve 101 having a planar boundary 101a that is recessed, tangent, or projecting relative to the planar end 100a, the intention being to obtain a planar boundary 101a that coincides with the plane of the planar end 100a. Regardless of the configuration, the planar end 100a and the planar boundary 101a define a free outer edge 1000. Thus, when the planar boundary 101a is recessed relative to the planar end 100a, the free outer edge 1000 coincides with the edge of the planar end 101a.Conversely, when the plane boundary 101a is in overhang relative to the plane end 100a, the edge 1000 is coincident with the edge of the . plane boundary 100a. When the plane boundary 101a has an overhanging portion and a complementary portion set back relative to the plane end 100a, the free external edge 1000 consists of the edges of the complementary portions overhanging the plane end 100a and the plane boundary 10la.

[0064] Regardless of the configurations, the edge 1000 is inscribed in a PI mounting plane.

[0065] The sleeve 101 is typically made integral with the first cylindrical portion of the component 10 by insertion, radial expansion and then spot welding, the spot welds which secure the sleeve 101 to the first cylindrical portion 100 being kept away from the edge 1000 so as not to disturb the MIG / MAG welding operation according to the invention.

[0066] The first cylindrical portion 100 and the coaxial sleeve 101 define a mounting axis A10.

[0067] The intersection of the mounting plane PI with the mounting axis A10 defines a mounting center CIO.

[0068] The first component 10 comprises, for example, a hook 102 and a body 103, the hook having bearing surfaces 102a, 102b. The surface 102a is inscribed in an oblong cut in the hook 102 and the surface 102b is inscribed in a face of the hook 102. The body 103 has flat bearing surfaces 103a, 103b stamped into the entry cone of the body 103.

[0069] The component 10 is pre-assembled to obtain a repeatable orientation of the mounting axis A10. This results in a precise radial localization of the center CIO relative to the surfaces 102a, 102b, 103a, 103b. To this end, the pre-assembly is carried out, for example, by positioning the hook 102 according to a first isostatic position that uses the surfaces 102a, 102b and by positioning the body 103 according to a second isostatic position that uses the center CIO and the surfaces 103a, 103b. A shouldered, spring-mounted bushing cooperating with the tubular cylindrical portion 100 typically guides the mounting axis A1 over a short length. According to such a pre-assembly, surfaces of components 102 and 103 in mutual contact are added to surfaces 102a, 102b on the one hand and 103a, 103b on the other hand to create the conditions for isostaticity of the hook 102 and the body 103.

[0070] Such a preparation radially locates the CIO center relative to surfaces 102a, 102b, 103a, 103b with a tolerance typically equal to 0.6 mm.

[0071] These pre-assembly conditions leave the orientation of the edge 1000 free relative to the reference surfaces 102a, 102b, 103a and 103b. The orientation error of the external edge 1000 relative to the surfaces 102a, 102b, 103a, 103b can reach the value of 2.0 mm to which is added a positioning error along the axis A10.

[0072] The pre-assembly of the hook 102 and the body 103 is typically carried out by MIG / MAG welding.

[0073] After pre-assembly, the surfaces 102a, 102b, 103a, 103b in combination can be used for isostatic positioning of the first component 10.

[0074] In one embodiment, the second component 11 is tubular. It has a second cylindrical portion 110 of revolution defining a second mounting axis Al 1. It comprises a tube 111 and a flange 112, the tube 111 comprising the second cylindrical portion 110, the flange 112 having reference surfaces 112a, 112b, 112c belonging respectively to a first bore, a second bore and a joint plane.

[0075] The second component 11 is pre-assembled so as to position the axis A11 precisely relative to the surface group 112a, 112b, 112c. For this purpose, and during pre-assembly, the tube 111 is positioned according to a third isostatic position using a theoretical axis A11, and the flange 112 according to a fourth isostatic position using the surface group 112a, 112b, 112c. Common contact surfaces of the tube 111 and the flange 112 are added to the two surface groups to create the conditions for the third and fourth isostatic positions during pre-assembly. A sleeve receiving the cylindrical portion 110 along its entire length can define the theoretical axis A1.

[0076] Prior to pre-assembly, a pre-existing gap between the tube 111 and the flange 112 can be eliminated by means of a radial expansion operation creating the conditions for obtaining common contact surfaces between the tube 11 and the flange 112.

[0077] Such pre-assembly conditions of the second component 11 locate the axis Ail relative to the surface group 112a, 112b, 112c according to a tolerance value typically equal to 0.6 mm

[0078] The assembly of the tube 111 and the flange 112 is carried out for example by MIG / MAG welding.

[0079] The first component 10 and the second component 11 are, for example, made of ferritic, austenitic or duplex stainless steel, typically from ferritic sheet in 1.4509 and ferritic casting in 1.4511. The first and second components 10, 11 can be thin, i.e. having a thickness between 0.6 mm and 1.0 mm or thicker, i.e. having a thickness between 1.2 mm and 2.5 mm, for example.

[0080] The thickness of the sleeve 101 is typically between 1.0 mm and 2.5 mm, for example is 1.0 mm.

[0081] The diameters of the first and second components 10, 11 in the fitting area are, for example, between 40 mm and 80 mm when the intended application is an exhaust system for passenger vehicles. The diameters are greater than 80 mm when the intended application is an exhaust system for commercial vehicles.

[0082] In a particular embodiment, notably shown in Figures 1 and 2, the first and second components 10, 11 are pre-assembled. The assembly 1 comprising the first and second pre-assembled components 10, 11 is obtained by crimping the first component 10 onto the second component 11 following a preliminary step implementing a crimping means 2.

[0083] The crimping means 2 includes a crimping jig 21. After insertion, an isostatic positioning of the first component 10 is obtained using the surfaces 102a, 102b, 103a, 103b. An isostatic positioning of the second component 11 is obtained using the surfaces 112a, 112b, 112c.

[0084] The crimping means 2 also includes a set of jaws 22 suitable for radically and plastically crimping the first component 10 onto the second component 11, the crimping location being repeatable relative to the surfaces 102a, 102b, 103a, 103b, 112a, 112b, 112c.

[0085] Before crimping, several conditions are met:

[0086] - the A10 mounting axis, the CIO working center, the second axis The Ail fittings are substantially aligned taking into account the location errors of the A10 axis relative to the group of surfaces 102a, 102b, 103a, 103b and of the Ail axis relative to the group of surfaces 112a, 112b, 112c,

[0087] - the surfaces 112a, 112b, 112c are positioned nominally relative to the group of surface 102a, 102b, 103a, 103b.

[0088] After crimping, results are obtained, some of which are advantageous:

[0089] - the sleeve 101 increases the clamping force and the relative risk of slippage of the The first and second components 10, 11 are eliminated. The assembled and crimped unit 1 is therefore suitable for handling, particularly when the first component 10 is of thin thickness.

[0090] - the surface group 102a, 102b, 103a, 103b can advantageously serve as a surface reference for creating the conditions for isostaticity of the crimped and fitted assembly 1,

[0091] - the set 1 has a set portion 12 which defines an axis of work Al, the working axis Al being located radially and precisely relative to the reference surface 102a, 102b, 103a, 103b, the effect of the subsequent elastic return of the crimping being negligible,

[0092] - the working axis Al is located relative to the surface 102a, 102b, 103a, 103b ty pitting according to a tolerance value of 0.3 mm, lower than that corresponding to the A10 axis of the first raw welded component.

[0093] - after crimping, the edge 1000 fits into a work plane PI,

[0094] - the axis Al and the plane PI define by intersection a working center Cl,

[0095] - the fitted portion 12 and the edge 1000 define a shoulder 13,

[0096] - the crimped, fitted portion 12 has a thickness, for example, between 1.6 mm and 4.0 mm, preferably equal to 1.8 mm.

[0097] - the line of intersection between the work plane PI and the second cylindrical portion 110 defines a lap joint 14, the gap between the first cylindrical portion 100 and the second cylindrical portion being less than 0.2 mm at the lap joint 14,

[0098] After crimping, the location error of the shoulder 13 can reach the value of 3.0 mm relative to the reference surface 102a, 102b, 103a, 103b.

[0099] Such a localization defect is the consequence of the angular dispersion of the free outer edge 1000 relative to the theoretical working axis Al and of the localization defect of the center Cl relative to this same theoretical working axis Al.

[0100] Such a localization defect increases drastically with the diameters of the cylindrical portions 100 and 110.

[0101] With reference to figures 1, 3, 4 and 5 and according to a preferred embodiment, a welding installation 3 comprises an automated system not shown, a welding head 30, a positioner / rotator 31, a retractable stop 32, a mobile carriage 33, a welding jig 34, a cardan joint 35.

[0102] The automaton allows the actions of the welding head 30, the positioner 31, the retractable stop 32, the carriage 33, the welding jig 34, the cardan 35 to be controlled according to a time line specific to a unit manufacturing cycle including a referencing and a welding.

[0103] The automatic jig 34 is configured to position and clamp the fitted assembly 1.

[0104] The free outer edge 1000 of the fitted assembly 1 is inscribed in the plane PL.

[0105] The automated welding head 30 is typically manipulated by a robot comprising six or seven axes. The welding head incorporates MIG / MAG technology, the advantages of which are productivity and relative tolerance.

[0106] the automatic machine 3 includes an automatic positioner 31, itself comprising a chassis 310.

[0107] The chassis 310 can be fixed or mobile relative to the workshop.

[0108] When the chassis 310 is mobile, the automated positioner 31 can be a turner capable of rotating the chassis 310 around an axis A2 relative to a frame 311, said frame 311 being fixed relative to the workshop.

[0109] The automatic stop 32 is retractable relative to the chassis 310, said stop 32 being movable between a retracted position and a reference position, said stop defining, in the reference position, a repeatable reference plane P3 in position relative to the chassis 310.

[0110] The automated retractable stop 32 typically comprises a set of stops 320 and a retraction mechanism (not shown), enabling assistance in changing position of the stop set, the stop set selectively moving from a retraction position to a reference position.

[0111] The stop set 320 includes, for example, two first surfaces 320a which define in reference position and in tangency a reference plane P3. The plane P3 is opposite the plane of the free outer edge 1000 when the assembly 1 is positioned and clamped in the template 34.

[0112] The plane P3 is perpendicular to the axis A2 of the turner 31.

[0113] The stop set also includes second surfaces 320b which define a reference center C3 in a reference position and in a common area. The referencing means 3 is designed so that the reference center C3 lies on the axis A2.

[0114] The retraction mechanism comprises a fixed part and a moving part, the stop set 320 being fixed to the moving part. The retraction mechanism is designed to position the stop set 320 in a repeatable manner relative to the frame 310.

[0115] According to a first variant, the fixed part of the retraction mechanism is embedded in the chassis 310 and the moving part has a positioning tolerance under force sufficient to ensure the repeatability of the positioning of the set of stops 320.

[0116] According to another variant, the fixed part is linked to the reference frame defined by the workshop. The frame 310 may have a double form and the moving part of the retraction mechanism a double counter-form, the double form and the double counter-form being able to be interlocked and indexed to each other. A flexible / compliant connection may typically be added between the counter-form and the moving part. In the interlocked and indexed state, the form and the counter-form impose a repeatable working position of the stop set 320 relative to the frame 310.

[0117] The automated trolley 33 is mobile in translation relative to the chassis 310 between a rearward position and a working position. The translational direction X of the trolley is typically perpendicular or substantially perpendicular to the reference plane P3. It includes a first reversible locking means 330. The reversible locking means 330 is, for example, a brake actuated by a linear actuator, such as a double-acting pneumatic cylinder connected to a valve which is itself electrically controlled by the PLC.

[0118] In a particular embodiment, the mobile carriage 33 also includes an actuator 331, a rail 332, and a shuttle 333, the rail 332 and the shuttle 333 performing the function of a slide. The rail 332 fixed to the frame 310 constrains the shuttle 333 to move in a horizontal or inclined direction X. The rail also includes a rear stop (not shown). The actuator 331 allows the shuttle to be moved in a forward or reverse direction by The movement of the shuttle 333 in the return direction is stopped by the rear stop. The actuator 331 is typically a linear actuator, such as a double-acting pneumatic cylinder connected to a valve electrically controlled by the PLC. The cylinder is sized to produce a force capable of moving the shuttle 333, the universal joint 35, the welding jig 34, and the assembly. It is capable of resisting the friction forces associated with the operation of the referencing device 3. The effective stroke of the cylinder is, for example, between 1 and 2 cm.

[0119] The blocking of the translation of the carriage 33 after a forward or reverse movement is achieved by activating the first reversible locking means 330.

[0120] The unlocking of the translation of the carriage 33 before a forward or return movement is obtained by releasing the first reversible locking means 330.

[0121] The cardan joint 35 connects the template 34 to the carriage 33.

[0122] The automatic gimbal 35 comprises a first pivoting member 351 about a substantially horizontal axis and which includes a return element 3510 and a second pivoting member 352 which includes a pre-positioning element 3520, the return element 3510 and the pre-positioning element 3520 being able to pre-orient the plane PI substantially parallel to the plane P3 in the rearward position.

[0123] The cardan 35 is therefore mobile in rotation relative to the shuttle 333 along a substantially horizontal Y axis by means of the first pivoting element 351.

[0124] It is typically rotated about an axis Z substantially perpendicular to the direction X by means of the second pivoting element 352.

[0125] The X direction and the pivot axes Y, Z typically form a right trihedron.

[0126] The Z-axis can be vertical if the chassis 310 imposes an orientation of the X-axis ho rizontal before the start of the work / welding operation.

[0127] The Z axis can be tilted if the chassis 310 is tilted relative to the horizontal to facilitate engagement of the work / welding operation.

[0128] Each pivoting element 351, 352 typically comprises a rotating shaft and a bearing.

[0129] The first pivoting element 351 includes the angular return element 3510 which opposes the incident couples acting on the assembly 1 positioned and clamped on the template 34 along the Y axis.

[0130] The angular return element 3510 pre-orients the assembly 1, positioned and clamped around the Y-axis, in the pitch direction. The pre-orientation can be adjusted when the return element includes an adjustment means such as opposingly mounted adjusting screws 35100a and 35100b.

[0131] The first pivoting element 351 includes a reversible locking means 3511 suitable for locking / unlocking the rotation of the gimbal 35 around the Y axis in the direction of pitch.

[0132] The second pivoting element 352 includes an angular pre-positioning element 3520 which pre-orients the gimbal 35 along the Z axis in the yaw direction.

[0133] According to a first embodiment, the pre-positioning element may consist of two retractable angular stops between a pre-positioning position and a working position. In the pre-positioning position, the two stops limit the yaw rotation of the gimbal 35. In the working position, the angular displacement of the gimbal 35 in the yaw direction is free.

[0134] According to a second variant, the angular pre-positioning element 3520 is an angular return element operating on the principle of the first pivoting element 351.

[0135] The second pivoting element 352 includes a reversible locking means 3521 capable of blocking / unlocking the rotation of the gimbal 35 around the Z axis in the yaw direction.

[0136] With reference to [Fig.5], the angular return element 3510 incorporates an adjustment function intended to pre-orient the template 34 relative to the chassis 310 and the reference plane P3 around the Y axis. The return element 3510 is similar to a pitch corrector.

[0137] In a preferred embodiment and in the rest of the description, the angular pre-positioning element 3520 is an angular recall element.

[0138] The angular return element 3520 also incorporates an adjustment function intended to pre-orient the template 34 relative to the chassis 310 and the reference plane P3 around the Z axis. The return element 3520 is similar to a yaw corrector.

[0139] The pitch and yaw correctors 3510, 3520, respectively comprise pairs of compression and opposing springs 35100a,b and 35200a,b, cams 35101, 35201 fixed to the shafts 3512, 3522 of the first and second pivoting members, and pairs of adjustable rear stops 3520la,b and 35202a,b. The adjustable rear stops 3520la,b and 35202a,b are respectively linked to bearings of the pivoting members 351, 352. Each of the cams 35101, 35102 has two flat faces extending radially relative to the axis of each of the pivots. Each of the springs of the pairs 35100a,b and 35200a,b has two ends bearing respectively on one of the adjustable stops and on one of the two faces of the cams 35101,35102.

[0140] The adjustment arrangements of the pitch and yaw correctors 351, 352 allow a pre-orientation of the group 36 formed by the assembly 1 and the welding jig 34 relative to the chassis 310.

[0141] The distance of the cam to the pivot axis, the dimensioning of the springs 35100a,b and 35200a,b and their respective compression determine torques around the pivot axes Y,Z. capable of correcting the orientation of the template 36 in the direction of pitch or yaw.

[0142] The compliant arrangements of the pitch and yaw correctors give the group 36 an angular flexibility / stiffness making it suitable for angular displacements around the Y and Z axes and therefore around the articulation point O under the effect of an incident moment.

[0143] Thus, after adjusting the rear stops 35102a,b and 35202a,b, the group 36 occupies a first equilibrium state characterized by an adjustment angle Q1Y along the Y axis and an adjustment angle Q1Z along the Z axis.

[0144] Under the effect of additional resultant moments (MY) and (MZ) involved during the different stages of the process, the angles QY and QZ evolve and reach values ​​QNY and QNZ associated with a series N of equilibrium states.

[0145] The pitch corrector 351 gives RTY stiffness to group 36 along the Y axis.

[0146] The yaw corrector 352 gives an RLZ stiffness to the group 36 along the Z axis.

[0147] Thus, the additional moments can be written:

[0148] (MY) = RTY x (QNY - Q1Y) and (MZ) = RLZ x (QNZ - Q1Z).

[0149] The welding jig 34 fixed to the gimbal 35, itself fixed to the carriage 33, is therefore suitable to be moved in rotation and translation relative to chassis 310.

[0150] The welding jig 34 has reception surfaces 3411 configured to accommodate the bearing surfaces 102a, 102b belonging to the hook 102 of the first component 10 and therefore of the crimped fitted assembly 1.

[0151] The welding jig 34 also includes reception surfaces 3412 configured to accommodate the bearing surfaces 103a, 103b belonging to the body 103 of the first component 10 and therefore of the fitted and crimped assembly 1.

[0152] The positioning of the crimped and fitted assembly 1 according to the bearing surfaces 102a, 102b, 103a, 103b is isostatic.

[0153] The receiving surfaces 3411, 3412 together form the receiving surface 341 suitable for receiving the support surfaces 102a, 102b, 103a, 103b, the assembly 1 being positioned isostatically.

[0154] The jig can also include pneumatic clamps controlled by the PLC which allow clamping of assembly 1 after positioning.

[0155] With reference to figures 1, 3, 4, 6 and 7, a welding process is implemented to weld the assembly 1 using the referencing means 3 according to the preferred embodiment, the first component 10 and the second component 11 being pre-assembled by crimping.

[0156] The referencing means 3 includes the positioner 31, the retractable stop 32, the mobile trolley 33, the mobile platform 34 and the welding jig 35.

[0157] A welding device not shown using a welding head 30 completes the installation 3.

[0158] The process comprises, during a given cycle, the following automatic steps:

[0159] - a step consisting of placing the stop 32 in the retracted position and the carriage 33 in in the rearward position, the translation of the carriage 33 and the rotations of the cardan 35 are blocked respectively by the reversible locking means 3511, 3521.

[0160] - a step consisting of positioning and clamping the assembly 1 fitted onto the template of welding 34, the assembly 1 positioned and clamped defining the work plane PI, the work axis Al and the work center Cl, the work center Cl being substantially coincident with the articulation point O of the cardan joint 35,

[0161] - a step consisting of unlocking the rotating gimbal 35, the assembly 1 occupying a The first equilibrium state, pre-positioning plane PI parallel to plane P3, achieves parallelism on average over a production batch. According to the preferred manufacturing method, which involves pre-assembling components 10 and 11 by crimping, axis Al is positioned repeatably relative to surfaces 102a, 102b, 103a, and 103b, and therefore relative to the mounting surfaces 341 of template 34. Thus, the axes Al of a production batch are aligned with a theoretical axis Alth of template 34. The adjustment settings of the universal joint 35 are used to pre-align axis Alth with the center C3 of the stop in the reference position. Assembly 1 in the example has a second fitted portion 110 extending beyond the first cylindrical portion 100.With axis Al directed towards the center C3, the stop 32 is configured to cooperate radially with the overhanging portion 1100 along axis Alth, when assembly 1 occupies the first equilibrium state and the stop 32 is in the reference position. According to such a configuration, the portion 1100 is able to slide during the translation of the carriage along the stop 32 in the reference position.

[0162] - a step consisting of unlocking the translation of the carriage 33 by releasing the first reversible locking means 330 then to exert a force F on the carriage 33, the carriage 33 and the assembly 1 moving towards the stop 32 along the X axis. the stop can be configured to cooperate axially with the end 1000. Given the configuration of the stop 32 and the axis Al aligned with the axis Ath and directed towards the center C3, the overhanging portion 1100 slides along the stop 32.

[0163] - a step consisting of simultaneously sliding the overhanging portion 1100 along of the stop 32 and the end 1000 to the surface of the stop 32, the stop being in reference position.

[0164] - a step consisting of blocking the translation of the carriage 33 with the first means of reversible locking 330, and to lock the rotations of the gimbal 35.

[0165] - a step consisting of putting the stop 32 in the retracted position.

[0166] - a step consisting of welding by bringing the welding head 30 into alignment from edge 1000 which is a welding edge, for example using MIG / MAG technology.

[0167] A preferred embodiment of the process is described below:

[0168] The chassis 310 has a double shape and the stop 32 has a fixed part and a movable part, the movable part comprising a double counter-form, not shown, suitable for indexing and fitting with the double form of the chassis 310.

[0169] A flexible / compliant connection between the fixed part and the moving part of the stop 32 allows the double form and double counter-form to fit together and index each other.

[0170] In the reference position, the double form and the double counter-form are embedded and indexed.

[0171] To obtain the retraction position, the stop set 320 is retracted, the double counter form being released from the double embedding and the double indexing.

[0172] The movable part is typically configured to move the stop set 320 away from the workspace in the retracted position, eliminating potential interference between the welding head 30 and the stop set 320.

[0173] During a previous cycle, the actuator 331 moved the carriage 33 into the reverse position.

[0174] Before loading assembly 1 onto template 34, the first reversible locking means 330 blocks the translation of the carriage 33 and the reversible locking means 3511, 3521 block the 2 pivot links of the cardan 35.

[0175] To obtain the loading state, assembly 1 is positioned manually or automatically on the welding jig 35. The bearing surfaces 102a, 102b, 103a, 103b of assembly 1 are brought into contact with the receiving surfaces 3411, 3412. Assembly 1 is clamped manually or automatically and the clamping can be confirmed automatically.

[0176] Assembly 1 defines the work plane PI, the work axis Al and the work center Cl relative to template 34.

[0177] Assembly 1 and the welding jig 34 are configured so that the working center Cl is substantially coincident with the pivot point O. Such a configuration minimizes / eliminates the moment values ​​associated with the friction forces of the outer edge 1000 on the stop 32, the action of which opposes the alignment of planes PI and P3. This technical effect is described in detail later in the text.

[0178] The free outer edge 1000 of the shoulder 13 is a welding edge.

[0179] To pre-position the free outer edge 1000 and the overhanging portion 1100 tively to the stop 32, the cardan 35 is unlocked, the resultants of the moments exerted respectively around the pivot axes Y and Z being zero, the assembly 1 occupying a first state of equilibrium.

[0180] Along the Y-axis, the first equilibrium state involves a moment GY 1 associated with a vertically directed gravitational force fgy, applied to the center of gravity of group 36 and at a distance dgy from the Y axis.

[0181] The first state of equilibrium also involves a moment MY1 exerted by the pitch corrector 3510 in reaction to the moment GY1.

[0182] The moment MY1 is the resultant of the moments (MY11, MY12) exerted by the two opposing springs 35100a, b.

[0183] Along the pivot axis Z, the first state of equilibrium involves a couple MZ1 exerted by the yaw corrector 3520 on the group 36. The couple MZ1 is the resultant of the moments (MZ11, MZ12) exerted by the two opposing springs 35200a, b.

[0184] At the first equilibrium state, group 36 is finally subjected to the couple (GY1, MY1) along the Y axis and to the couple (MZ11, MZ12) along the Z axis.

[0185] The pitch corrector 3510 and the yaw corrector 3520 are set so that the working axis Al is aligned with the reference point C3.

[0186] The repeatable orientation of the axes Al relative to the reception surfaces 3411, 3412 and their alignment with the axis Alth of the template 34 makes this adjustment possible.

[0187] The pre-positioning of the edge 1000 and the overhanging portion 1100 relative to the stop 32 also includes the setting of the stop 32 to its reference position.

[0188] The stop which typically includes a stop set 320 has in reference position a passage section 320a defining in its center the reference point C3 and a surface 320b opposite the edge 1000 defining in tangency the reference plane P3.

[0189] When the stop 32 is placed in the reference position, the stop set 320 and the overhanging portion 1100 of the assembly 1 may be in a state of interference and then in a state of cooperation if the axis Al is not repeatable relative to the pre-positioned template 34.

[0190] By interference state, it is understood that a temporary or continuous contact between the overhanging portion 1100 and the stop clearance occurs when the stop 32 is referenced.

[0191] By state of cooperation it is understood that the axis Al aligns with the center C3, the section 320b being dimensioned relative to the overhanging portion 1100 so that a clearance is established, the stop 32 and the assembly being mechanically linked by guidance and not by fixed connection.

[0192] The overhanging portion 1100 and the stop 32 can be directly in a state of cooperation if the axis Al is repeatable relative to the template 34 and the template 34 is pre-positioned so as to align the axis Alth with the center C3.

[0193] The stop set 320 and the overhanging portion 1100, by interfering and then cooperating, modify the torque values ​​relative to the Y and Z axes by modifying the compression of the springs 35100a,b and 35200a,b.

[0194] The stop set 320 and the overhanging portion cooperate directly without interfering do not change the torque values ​​relative to the Y and Z axes.

[0195] In all cases, after referencing the stop 32, the group 36 finds an intermediate equilibrium state characterized by torque values ​​(GY2, MY2) and (MZ21, MZ22).

[0196] The intermediate equilibrium position is in practice little different from the first equilibrium position and the torque values ​​(GY1, MY1) (GY2, MY2) and (MZ11, MZ12) (MZ21, MZ22) are substantially identical.

[0197] The torque values ​​(GY1, MY1) (GY2, MY2) and (MZ11, MZ12) (MZ21, MZ22) are equal when the overhanging portion 1100 cooperates perfectly with the stops 32 and / or the axis Al coincident with the theoretical axis Alth is aligned with the center C3.

[0198] To obtain such cooperation, the stop 32 presents, for example, a substantially square passage section.

[0199] In general, the passage section of the stop 32 is dimensioned to facilitate the engagement of the overhanging portion 1100 relative to the stop 32 in the interference state.

[0200] The section of the stop 32 is also dimensioned to guide the overhanging portion 1100 in the cooperative state.

[0201] The section of the stop is further dimensioned in order to obtain an optimal clearance with the overhanging portion 1100, the optimal clearance having the function of guiding and positioning the surface 1100 in the state of cooperation.

[0202] The stop 32 can be chamfered according to the passage section to guide the overhanging portion 1100 around the center C3 in the cooperative state.

[0203] Thus, the overhanging portion 1100 retains rotational freedoms around the Y and Z axes in a state of cooperation.

[0204] Optionally, the stop set 320 is chamfered along the faces / edges 320b of the stop in the reference position.

[0205] The stop set may include reinforcements.

[0206] The stop set 320 is for example made of hardened and tempered steel.

[0207] The stop set 320 has, for example, received a nitriding treatment on its surface.

[0208] The 2 stops of the game 320 can index each other by a tenon mortise system so that their faces 320a opposite the free external edge 1000 are perfectly coincident in the same plane.

[0209] In a particular embodiment, the work center Al is located less than 1 cm from the reference plane P3 when the assembly 1 occupies the first equilibrium state.

[0210] In another embodiment, the working center Al is located at a distance from the reference plane P3 equal at most to the length of the overhanging portion 1100 when the assembly 1 occupies the first equilibrium state.

[0211] Finally, in the first state of equilibrium, the assembly 1 whose overhanging portion 1100 cooperates with the faces / edges 320b of the stop set 320, presents a pre-aligned PI work plane on average on a manufacturing batch with the P3 plane.

[0212] The cardan joint 35 is configured so that the fitted assembly 1 occupies a second equilibrium state in which planes PI and P3 coincide when the carriage 33 is in the working position,

[0213] In addition, the second equilibrium state is obtained from the first equilibrium state by automatic movement of the carriage 33 between the recoil position and the working position, by rotation of the pivoting members 351, 352 and by sliding and friction of the free outer edge 1000 on the stop 32.

[0214] To obtain the second equilibrium state, a force F is typically exerted on the carriage 33, the group 36 and therefore the assembly 1 moving in a forward direction towards the stop 32 in the reference position.

[0215] During the movement, the section of the stop 32 guides the overhanging portion 1100 of the assembly 1, the conditions of alignment of the working axis Al with the center C3 being consequently maintained.

[0216] At an instant ti of the displacement, the edge 1000 comes into contact at least punctually with the surface 320a.

[0217] At time ti and after, the group 36 transmits a force F on the stop 32 by producing a force vector fn normal to the surface 320a and a force vector ft parallel to the surface 320a, the 2 force vectors fn and ft evolving along a time line t.

[0218] In reaction to the effort F, the stop 32 exerts a counter-effort CF on the group 36 by producing a force vector cfn normal to the surface 320a and a force vector cft parallel to the surface 320a, the 2 force vectors cfn and cft evolving along the time line t.

[0219] The force vectors (fn, ft, cfn, cft) are applied at a common point / midpoint of a common surface P belonging to the surface 320a, the locus of the point / midpoint P evolving along the time line t.

[0220] At time ti and after, couples (MnY, CMnY), (MtY, CMtY), (MnZ, CMnZ), (MtZ, CMtZ) with respect to the Y and Z axes and associated with the force vectors (fn, ft, cfn, cft) are exerted simultaneously on the stop 32 and the group 36. The moments CMnY, CMtY, CMnZ, CMtZ which are exerted specifically on the group 36 are a function of the respective values ​​[fn], [ft], [cfn], [cft] and the respective distances dnY, dtY, dnZ, dtZ of these force vectors with respect to the Y and Z axes.

[0221] At time ti and afterwards, the group 36 is subjected along the Y axis to the moments CMnY, CMtY, MY, GY.

[0222] The moment CMnY which is a function of [cfn] and dnY directs the rotation of group 36 in the direction of the alignment of the PI plane with the P3 plane.

[0223] The moment CMtY, which is a function of [cft] and dtY, opposes the rotation of the group 36 in the direction of the alignment of plane PI with plane P3.

[0224] The resultant force (MY, GY) is a function of the angular stiffness RTY of the pitch corrector 3510 and the angular displacement (QY-Q1Y) of group 36 relative to the first equilibrium state. It opposes the rotation of group 36 in the direction of alignment of plane PI with plane P3.

[0225] The angular stiffness RTY is substantially constant and the angular displacement (QY-Q1Y) of group 36 relative to the first equilibrium state along the Y axis is bounded in value.

[0226] The resultant (MY, GY) is also bounded in value.

[0227] At time ti and afterwards, the group 36 is subjected along the Z axis to the moments CMnZ, CMtZ, MZ.

[0228] The moment CMnZ is a function of [cfn] and dnZ. The moment CMnZ directs the rotation of group 36 in the direction of an alignment of the plane PI with the plane P3.

[0229] The moment CMtZ is a function of [cft] and dtZ. The moment CMtZ opposes the rotation of group 36 in the direction of an alignment of the PI plane with the P3 plane.

[0230] The torque MZ is a function of the angular stiffness RLZ of the yaw corrector 3520 and the angular displacement (QZ-Q1Z) of the group 36 relative to the first equilibrium state along the Z axis. The torque MZ opposes the rotation of the group 36 in the direction of an alignment of the PI plane with the P3 plane.

[0231] The angular stiffness RLZ is substantially constant and the angular displacement (QZ-Q1Z) of group 36 relative to the first equilibrium state along the Z axis is bounded in value.

[0232] The MZ couple is also bounded in value.

[0233] To create the conditions for alignment of the working plane PI with the reference plane P3, it is sufficient that at time ti the moments CMnY and CMnZ are simultaneously greater than the resultants (CMtY, MY, GY) and (CMtZ, MZ).

[0234] Otherwise, the edge 1000 butts up against the surface 320a of the stop set 320.

[0235] Between ti and tf, the forces cfn and cft are in a ratio depending on the properties of dynamic or static friction characterizing the contact between the edge 1000 and the surface 320a.

[0236] At time tf and after, the forces cfn2 and cft2 are in a ratio depending on the static friction properties characterizing the contact between the edge 1000 and the surface 320a.

[0237] Thus, if the sliding conditions are satisfied at time ti, the sliding continues until time tf when the PI plane aligns with the P3 plane, the properties of the contact not evolving between ti and tf.

[0238] According to a preferred embodiment, the working center Cl is contained within a sliding sphere centered on the articulation point O of the cardan joint 35 whose radius is equal to the location error of the center Cl relative to template 34.

[0239] Thus, according to the preferred embodiment, the lever arms dtY and dtZ are negligible or almost negligible. The moments CMtY and CMtZ are negligible or almost negligible and the resultants (CMtY, MY, GY) and (CMtZ, MZ) are bounded in value.

[0240] To create the conditions for alignment of planes PI and P3, it suffices to increase the value of the force F in a necessary and sufficient manner. Thus, the value of the counter-force CF, and therefore the value of the normal component cfn, and consequently the values ​​of CMnY and CMnZ, exceed respectively those of the resultants (CMtY,MY,GY) and (CMtZ,MZ), which are bounded.

[0241] In practice, the main contributor to the positioning error of the working center Cl relative to the articulation point O is the positioning error of the center Cl relative to the template 34 and the variation of the tool dimension between the template 34 and the articulation point O of the cardan 35.

[0242] Statistically and by experience, a working center Cl located in a sliding sphere centered on the point O and with a radius equal to 5 times the location error of the center Cl relative to the template 34 is sufficient to optimize the value of the moments involved during the sliding of the edge 1000 on the stop 32.

[0243] The loading, first equilibrium stage and second equilibrium stage steps according to the process involving assembly 1 and implementing welding installation 3 make it possible to obtain the following advantageous results:

[0244] - In the loading stage, the reversible locking means 330 blocks the translation of the carriage 33 and the reversible locking means 3511, 3521 block the rotations of the cardan 35.

[0245] Thus, the welding jig 34 is locked in position and the loading of assembly 1 onto the welding jig 34 automatically or manually is facilitated.

[0246] - In the step of obtaining the first equilibrium state, the pitch correctors 3510 and yaw 3520 are set to orient, after unlocking the rotations of the gimbal 35, the working axis Al substantially perpendicular to the reference plane P3 and direct the axis Al substantially towards the center C3.

[0247] Thus, when the stop 32 is referenced, the overhanging portion 1100 interferes with and then directly cooperates with the surface 320b of the stop set 320, the working axis Al and the center C3 passing from a substantially aligned state to an aligned state, the group 36 occupying an intermediate equilibrium state not very different from the first equilibrium state. The friction that opposes obtaining the second equilibrium state is thus limited.

[0248] - In the step of obtaining the second equilibrium state, the cart 33 moves according to a direction perpendicular to plane P3 by applying force F and surface 320b guides the free portion 1100 of assembly 1, the conditions for the alignment of axis Al with the center C3 remaining in position. At time ti, additional moments CMnY, CMtY, CMnZ, CMtZ associated with the counterforce CF are applied to group 36, the moments CMnY and CMnZ opposing the resultants (CMtY,MY,GY) and (CMtZ,MZ).

[0249] The working center Cl, substantially coinciding with the articulation point O, limits the magnitude of the moments CMtY and CMtZ by lever arm effect, and the moments CMnY and CMnZ exceed the magnitudes of the resultants (CMtY,MY,GY) and (CMtZ,MZ) at time ti. The sliding of the edge 1000 on the surface 320a of the stop clearance 320 is made possible.

[0250] When the surface 320a receives a nitriding treatment, the coefficient of friction of the assembly 1 on the stop 32 is reduced, and the values ​​of the moments CMtY and CMtZ are reduced accordingly. The sliding of the edge 1000 on the surface 320a of the stop clearance 320 is promoted.

[0251] The first tubular component 10 being thickened by the sleeve 101 mounted on the inner surface of the cylindrical portion 100, the working plane PI and the reference plane P3 more easily find the conditions of alignment at time tf.

[0252] The surface 320b of the stop set 320 guiding the free portion 1100 of the assembly 1, the conditions of an alignment of the working axis Al with the reference point C3 are maintained between ti and tf.

[0253] In a work engagement step, the first reversible locking means 330 blocks the translation of the carriage 33 and the reversible locking means 3511, 3521 block the rotations of the cardan 35 and the stop 32 is retracted.

[0254] In this work engagement stage, the following advantageous results:

[0255] - After blocking the translation, the force F exerted by the actuator 331 on the carriage 33 is transmitted only to the locking means 330 and is no longer transmitted to the stop 32.

[0256] Thus, the stop 32 is free of constraint along the X axis.

[0257] - Optionally, the force F can be released by the actuator 331 in such a way automatic as a result of the confirmation of the locking actions by the organs 330, 3511, 3521.

[0258] - According to a preferred embodiment, the chassis 310 may include a double form and the moving part of the stop retraction mechanism 32 a double counter form, the double form and the double counter form being able to find the conditions of a fixed and an indexing.

[0259] Thus, after retraction of the stop 32, the workspace delimited by the plane P3 is free of any component other than the frame 310 if it is configured as such. This clearance facilitates the approach and orientation of the welding head 30 relative to the welding edge 1000.

[0260] - The assembly 1 comprising the first and second components 10, 11 is obtained by crimping of the second component 11 onto the first component 10 following a preliminary pre-assembly step implementing the crimping means 2.

[0261] Thus, the welding jig 34, which includes the receiving surfaces 3411 and 3412 suitable for receiving the support surfaces 102a, 102b, 103a, 103b belonging to the first component 10 only, can be configured to leave the workspace delimited by the work plane P3 free. The welding head 30 can be approached and oriented relative to the welding edge 1000 without interfering with the welding jig 34.

[0262] Such ease of access promotes the conditions and quality of welding.

[0263] In a welding step, the assembly 1, comprising the first and second components 10, 11 pre-assembled by crimping, is welded along edge 1000 by bringing the welding head 30, which uses MIG / MAG technology, close to the edge. A circular weld bead is deposited around the periphery, along the joint 14.

[0264] The welding head 30, which defines an axis A4, approaches the edge 1000 at an initial instant tsi of the welding, and then, after welding, moves away from the edge 1000 at a final instant tsf. Optionally, the weld bead comprises several adjacent beads with overlaps. During the welding operation, i.e., between tsi and tsf, the rotator / positioner 31 rotates the assembly 1, and thus the shoulder 13, about an axis A2. The positioner 31 and the frame 310 are configured so that the axis A2 contains the center C3 and is parallel to the plane P3 as precisely as possible.

[0265] With reference to [Fig. 7], MIG / MAG technology tolerates variations in the distance between the welding head 30 and the lap joint 14 when the head 30 remains directed towards the edge 1000. Such a distance (in English: "stick out") which is typically set to achieve the average value of 13 mm supports variations in the range [8 mm; 18 mm],

[0266] Thus, the conformity of the weld bead is not altered if the distance is maintained within the range [8 mm - 18 mm]. Typically, the weld bead penetration criterion will remain compliant despite these variations.

[0267] With reference to [Fig.7], MIG / MAG technology does not tolerate offsets of the welding head 30 relative to the lap joint 14, whether the head is in line with the single thickness or the double thickness.

[0268] Thus, the penetration depth of the weld bead may be unacceptable and weld defects (overpenetration, perforations) are more likely to occur when the overlap and non-overlap areas have dissimilar thicknesses.

[0269] According to a preferred embodiment, the welding head 30 is oriented at time tsi substantially perpendicular to the axis A2 of the turner, the angle a between the axis A4 of the head 30 and the axis A2 being in an interval [60°, 90°], preferably [80°, 90°].

[0270] The welding step involving assembly 1 and implementing welding installation 3 makes it possible to obtain the following advantageous results:

[0271] - The assembly 1 comprising the first and second components 10, 11 is obtained by crimping of the second component 11 onto the first component 10 following a preliminary step implementing the crimping means 2. The lap joint 14 has a gap of less than 0.2 mm as a consequence of the crimping.

[0272] Thus, the welding conditions of the first component 10 with the second component 11 are improved, a limited gap at the clincher joint 14 being a parameter to be controlled to ensure the conformity of the weld bead.

[0273] - At time tsi, the welding head 30 is oriented perpendicularly to the axis of the Turner A2. The head 30 is also directed towards the edge 1000 at an initial distance of 13 mm. In addition, the shoulder 13 is aligned with the planes PI, P3 perpendicular to the axis of the turner A2.

[0274] Thus, between tsi and tsf, i.e., during the rotation of the rotator 31, the welding head 30 remains directed towards the welding edge 1000 substantially perpendicular to the axis of the rotator A2, and the "stick out" between the head 30 and the edge 1000 remains within the range [8 mm - 18 mm]. The position of the welding head 30 relative to the welding edge 1000 exhibits little or no offset, and the risks of weld defects are eliminated.

[0275] During production and during the rotation of the turner 31, the edge 1000 is the site of a radial beat dispersion relative to the axis A2 tolerated by the MIG / MAG technology.

[0276] - Between tsi and tsf, the work center Cl is substantially confused with the work center of Reference point C3, the reference center C3 belonging to axis A2. Thus, the radial runout relative to axis A2, whose edge 1000 is located, is minimized. The dispersion of radial runout during production is also minimized.

[0277] - Edge 1000 is the site of a negligible axial beat relative to head 30 see zero, therefore typically within a range [-0.5 mm, 0.5 mm]. The requirement for the absence of weld defects such as overpenetration, underpenetration, or burn-through is met.

[0278] A larger axial runout typically greater than + / - 1.5 mm would not have been tolerated by MIG / MAG technology.

[0279] - The first tubular component 10 comprises a surface-mounted sleeve 101 in external to the first cylindrical portion 100, said sleeve 101 having a planar boundary 101a aligned with the planar end 100a, the planar faces 100a and 101a delimiting the shoulder 13 and the weld edge 1000. Between tsi and tsf, that is to say during Due to the rotation of the swivel 31, the welding head 30 is directed towards the welding edge 1000 substantially perpendicular to the axis of the swivel. Such an orientation relative to the edge 1000 and the joint 14 tends to increase weld penetration.

[0280] Thus, the thickening provided by the sleeve 101 is advantageous given the welding condition created by the orientation of the torch 30. The repeatability of the welding operation and the conformity of the weld bead are ensured.

[0281] The means according to the invention allows for referencing a joint of two components defining a work plane along a reference plane defined by a retractable stop. The function of the means is to eliminate axial runout associated with rotation about an axis perpendicular to the reference plane. Such a means can be advantageously used when the application process employs a tool / technology tolerating radial runout, the tool being able to work radially or axially, preferably axially.

[0282] Brushing, polishing, painting or other processes tolerating radial runout but not axial runout will advantageously use the means according to the invention for rotational work at a controlled distance in an axial direction.

[0283] The means according to the invention allows for referencing a joint of two components defining a work plane and a work axis simultaneously along a plane and a reference point defined by a retractable stop. The invention is applicable if the joint has a work axis whose positioning is repeatable, the orientation and position of the work plane relative to the work axis being variable. The function of the means is to eliminate axial runout when the joint is rotated about an axis perpendicular to the reference plane passing through the reference point. This means can advantageously be used when the application process employs a tool / technology tolerating radial runout, the tool being able to work radially or axially, preferably radially.

[0284] Welding, painting or other processes tolerating radial runout but not axial runout will advantageously use the means according to the invention for rotational work at a controlled distance in a radial direction. List of reference signs

[0285] 1 Set with handle

[0286] 10 First tubular component

[0287] 100 First cylindrical portion

[0288] 100a Flat end

[0289] 101 Sleeve

[0290] 101a Plane boundary

[0291] 102 Hook

[0292] 102a, 102b Hook bearing surfaces

[0293] 103 Body

[0294] 103a, 103b Body bearing surfaces

[0295] 1000 Edge

[0296] 11 Second component

[0297] 110 Second cylindrical portion

[0298] 1100 Overflow Portion

[0299] 111 Tube

[0300] 112 Bride

[0301] 112a, 112b, 112c Flange bearing surfaces

[0302] 12 portion set with handle

[0303] 13 Shoulder

[0304] 14 Clap joint

[0305] 2 Crimping means

[0306] 21 Crimping jig

[0307] 22 Jaw Set

[0308] 3 Machine

[0309] 30 welding head

[0310] 31 Positioner

[0311] 310 Chassis

[0312] 32 Retractable butt

[0313] 320 Set of stops

[0314] 320a Flat surfaces opposite the outer edge 1000

[0315] 320b Stop passage section

[0316] 33 Trolley

[0317] 330 First reversible locking means

[0318] 331 Actuator

[0319] 332 Rail

[0320] 333 Shuttle

[0321] 34 Template

[0322] 341 Reception areas

[0323] 3411 Hook-related reception areas

[0324] 3412 Body-related reception areas

[0325] 36 Group consisting of set 1 and template 34

[0326] 35 Cardan

[0327] 351 First pivoting member

[0328] 3510 Angular return element

[0329] 35100a,b Pair of springs

[0330] 35101 Came

[0331] 35102a,b Adjustable rear stop pair

[0332] 3511 Reversible angular locking means

[0333] 3512 Shaft of the first pivoting member

[0334] 352 Second pivoting member

[0335] 3520 Angular pre-positioning element

[0336] 35200a,b Pair of springs

[0337] 35201 Came

[0338] 35202a,b Adjustable rear stop pair

[0339] 3521 Reversible locking means

[0340] 3522 Shaft of the second pivoting member

[0341] PI Work Plan

[0342] P3 Reference Plan

[0343] Al Working axis

[0344] A10 First mounting shaft

[0345] Garlic Second shaft of assembly

[0346] A2 Chassis rotation axis

[0347] A4 Welding torch shaft

[0348] Cl Work Center

[0349] C3 Reference Centre

[0350] F Effort

[0351] CF Counter effort

[0352] G Force applied at the center of gravity

[0353] X Direction of movement of the trolley

[0354] Y Axis of the first pivoting member

[0355] Z Axis of the second pivoting member

[0356] O Point of articulation O

[0357] RTY Angular stiffness of the pitch corrector

[0358] RLZ Angular stiffness of the yaw corrector

Claims

Demands

1. Automatic machine (3) for referencing a set fitted (1), the fitted assembly (1) comprising: a first component (10) having a first cylindrical tubular portion (100), the first cylindrical tubular portion (100) having a free external edge (1000) which lies in a plane PI, a second component (11) having a second cylindrical portion (110), said second cylindrical portion (110) being fitted into the first tubular cylindrical portion (100), the automatic machine (3) comprising: an automatic positioner (31) comprising a frame (310), an automatic stop (32) retractable relative to the frame (310), said stop (32) being movable between a retraction position and a reference position, said stop defining, in the reference position, a reference plane P3 repeatable in position relative to the frame (310), an automatic carriage (33) movable in translation relative to the frame (310) between a recoil position and a working position, the translation direction of the carriage being perpendicular to the reference plane P3, an automatic jig (34) configured to position and clamp the fitted assembly (1), an automatic cardan joint (35) connecting the jig (34) to the carriage (33), comprising a first pivoting member (351) about a substantially horizontal axis, and comprising a return element (3510) and a second pivoting member (352) comprising a pre-positioning element (3520), the return element (3510) and the pre-positioning element (3520) being capable of pre-orienting the plane PI substantially parallel to the plane P3 in the recoil position, the fitted assembly (1) positioned and clamped in the jig (34) occupying a first state of equilibrium, the cardan (35) being configured so that the fitted assembly (1) occupies a second equilibrium state in which the planes PI and P3 are coincident when the carriage (33) is in the working position, the second equilibrium state being obtained from the first equilibrium state by automatic movement of the carriage (33) between the recoil position and the working position, by rotation of the pivoting members (351), (352) and by sliding and friction of the free outer edge (1000) on the stop (32).

2. Automatic machine (3) according to claim 1, wherein the carriage (33) comprises a reversible translation locking means (330) and an actuator (331), said reversible translation locking means (330) blocking / unblocking the translation of the carriage (33) relative to the chassis (310), the actuator (331) moving the carriage (33) between the rearward position and the working position, wherein the first pivoting member (351) comprises a reversible angular locking means (3511) and wherein the second pivoting member (352) further has an axis substantially perpendicular to the translation direction of the carriage (33) a reversible angular locking means (3521), the reversible angular locking means (3511, 3521) in combination automatically blocking / unblocking the rotation of the cardan (35).

3. Automatic machine (3) according to claim 1 or 2, wherein the jig (34) is rotationally mobile relative to the carriage (33) around an articulation point O of the cardan (35) and wherein the fitted assembly (1) positioned and clamped in the jig (34) defines a fitting axis Al, the axis Al being secant with the work plane PI at a work center Cl, the locus of points Cl being in a sliding sphere centered on the articulation point O of the cardan (35) and of radius equal to five times the positioning error of point Cl relative to the jig (34).

4. Automatic machine (3) according to any one of the preceding claims, wherein the stop (32) receives a surface treatment promoting the sliding of the free outer edge (1000) relative to the stop (32).

5. Automatic machine (3) according to any one of the preceding claims, wherein the stop (32) receives a surface treatment and / or a core promoting the wear resistance of the stop (32) by relative friction of the free outer edge (1000) with the stop (32).

6. Automatic machine (3) according to any one of the preceding claims, wherein the jig (34) defines a theoretical working axis Alth perpendicular to the plane P3 in the first equilibrium state, the stop (32) defining in reference position a reference point C3 relative to the frame (310), the angular return elements (3510) and angular pre-positioning elements (3520) being adjustable and pre-aligning the axis Alth with the reference point C3 in the first equilibrium state.

7. Automatic machine (3) according to any one of the preceding claims, wherein the fitted cylindrical portion (100) of the assembly (1) positioned and clamped in the jig (34) defines a repeatable axis Al relative to the jig (34) and aligned with the theoretical axis Alth, wherein further the assembly (1) has a second cylindrical portion (110) extending beyond the first fitted cylindrical portion (100), the extending portion (1100) of the second cylindrical portion (110) being guided by the stop (32) in the reference position when the cardan joint (35) is unlocked, the assembly (1) occupying the first equilibrium state.

8. Automatic machine (3) according to any one of the preceding claims, wherein the angular pre-positioning element (3520) is an angular return element.

9. An automatic method for referencing a fitted assembly (1) using an automatic machine (3), the fitted assembly (1) comprising: - a first tubular component (10) having a first cylindrical portion (100), said first tubular cylindrical portion (100) having a free outer edge (1000) inscribed in a plane PI, - a second component (11) having a second cylindrical portion (110), said second cylindrical portion (110) being fitted into the first tubular cylindrical portion (100), the method implementing: - the automatic machine (3), comprising: • an automatic positioner (31) comprising a chassis (310), • an automatic stop (32) retractable relative to the chassis (310), movable between a retracted position and a reference position, said stop (32) defining, in the reference position, a repeatable reference plane P3 in position relative to the chassis (310), • an automatic trolley (33) moving in translation relative to the chassis (310) between a rearward position and a working position, the direction of translation of the trolley being perpendicular to the reference plane P3, • an automatic jig (34) configured to position and clamp the fitted assembly (1), • an automatic cardan joint (35) connecting the jig (34) to the carriage (33), comprising a first pivoting member (351) about a substantially horizontal axis and comprising a return element (3510), and a second pivoting member (352) comprising a pre-positioning element (3520), the return element (3510) and the pre-positioning element (3520) being capable of pre-orienting the plane PI substantially parallel to the plane P3 in the recoil position, the assembly fitted (1) positioned and clamped in the jig (34) occupying a first state of equilibrium, the cardan joint (35) being configured so that the mounted assembly (1) occupies a second equilibrium state in which planes PI and P3 coincide, when the carriage (33) is in the working position, the automatic process comprising the following cyclic steps: - obtain the first state of equilibrium, - set the stop (32) as a reference, - obtain the second state of equilibrium, the second state of equilibrium being obtained from the first state balance by automatic movement of the carriage (33) between the recoil position and the working position, by rotation of the pivoting members (351), (352) and by sliding and friction of the free outer edge (1000) on the stop (32).

10. A method according to claim 9, wherein the carriage (33) comprises a reversible translation locking means (330) and an actuator (331), said reversible translation locking means (330) blocking / unblocking the translation of the carriage (33) relative to the chassis (310), the actuator (331) moving the carriage (33) between the rearward position and the working position, wherein the first pivoting member (351) comprises a reversible angular locking means (3511) and wherein the second pivoting member (352) has an axis substantially perpendicular to the translation direction of the carriage (33), further comprises an angular pre-positioning element (3520) and a reversible angular locking means (3521), the reversible angular locking means (3511, 3521) in combination automatically blocking / unblocking the universal joint (35) in rotation,the process comprising an automatic loading step prior to the step of obtaining the first equilibrium state in which the carriage occupies the recoil position, the carriage is locked in translation by means (330), the cardan joint (35) is blocked in rotation by means (3511, 3521) and the fitted assembly (1) is positioned and clamped on the jig (34).

11. A method according to claims 9 or 10, wherein the carriage (33) comprises a reversible translation locking means (330) and an actuator (331), said reversible translation locking means (330) blocking / unblocking the translation of the carriage (33) relative to the chassis (310), the actuator (331) moving the carriage (33) between the rearward position and the working position, wherein the first pivoting member (351) comprises a reversible angular locking means (3511) and wherein the second pivoting member (352) has an axis substantially perpendicular to the translational direction of the carriage (33), further comprises an angular pre-positioning element (3520) and a reversible angular locking means (3521), the reversible angular locking means (3511, 3521) in combination automatically blocking / unblocking the universal joint (35) in rotation,the process comprising a work engagement step subsequent to the step of obtaining the second equilibrium state in, in which the carriage occupies the working position, the carriage is locked in translation by means (330), the cardan (35) is blocked in rotation by means (3511,3521), the fitted assembly (1) being positioned and clamped on the template (34).

12. A method according to any one of claims 9 to 11, wherein a pre-assembly step of the first and second components 10 and 11 is carried out prior to the step of obtaining the first equilibrium state.

13. A method according to claim 12, wherein the pre-assembly step is crimping, wherein the jig (34) defines a theoretical axis Alth and wherein the crimping is carried out by isostatic positioning of the component 10 according to external bearing surfaces SI, the fitted cylindrical portion (100) of the assembly (1) after crimping defining a repeatable axis Al relative to the bearing surface SI, the repeatable axis Al being aligned with the theoretical axis Alth when the assembly (1) is positioned and clamped on the jig (34) according to the bearing surfaces SI.

14. A method according to any one of claims 9 to 13, wherein the machine (3) is a welding installation (3) and wherein a welding step is consecutive to the work engagement step.

15. A method according to claim 14, wherein the welding installation (3) comprises a welding head (30) defining an axis A4, wherein the stop (32) in the reference position defines a center C3 and wherein the positioner (31) rotates the frame (310) around an axis A2 perpendicular to the plane P3 and passing through the center C3, the welding step being carried out by aligning the axis A4 with the planes PI and P3 coinciding and rotating the frame (310) around the axis A2.

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