FR2886186A1 - Robotized arc welding installation with three welding torches fed with electricity, gas and cooling fluid via a flexible connection and feed system for tungsten inert gas and plasma arc welding operations - Google Patents

Abstract

An arc welding installation comprises some welding torches (16, 18, 20), supply sources (24, 26, 28) for feeding electricity, gas and cooling fluid to the torches and a robot arm (14) at one end of which is a mechanism for fixing it to one of the torches. The fixing mechanism the torch (16) to the robot arm also incorporates a system for connecting the torch to the electricity, gas and cooling fluid systems. An independent claim is also included for a lock plate for connecting and feeding a welding torch on a robot arm.

Description

2886186 1

  The invention relates to a robotic installation of arc welding, including TIG arc welding and plasma welding.

  The known robotic welding installations generally comprise a robot arm which can be equipped with welding torches of different types, which are used in turn according to the needs, the characteristics of the weld seam to be produced, the congestion of the torch, etc., the number of torches usable in an installation being variable and, very generally, between 3 and 10.

  Each torch is equipped with a bundle of cables and conduits which are connected by a switching box to means for supplying the torch with electrical energy, with plasmagenic gas and with protection, and with cooling fluid. These bundles of cables and conduits have a significant length (about 11 meters for example), they are heavy, bulky, inconvenient to handle and can hinder the movements of the robot arm. In addition, torch changes on the robotic arm are long and must be performed by an operator. In addition, when a torch is placed back on a support after being used, it must be disconnected from its bundle of cables and conduits to bring it up to maintenance and adjustment means, then reconnect it to its beam cables and ducts before it can be mounted on the robotic arm again. All of these operations must be done carefully and take a long time.

  The object of the invention is in particular to avoid these drawbacks of known robotic welding installations.

  It proposes for this purpose an arc welding installation, comprising welding torches of different types, torch supply means of electrical energy, gas and cooling fluid, and a robot arm having at one end means for fixing one of these torches, characterized in that the means for fixing a torch on the robot arm comprise means for connecting this torch to the means for supplying electrical energy, gas and fluid of cooling.

  With this characteristic of the invention, the torches are no longer permanently connected to bundles of cables and ducts which are long, heavy and bulky, they can be handled much easier for their assembly and disassembly on the robot arm and the latter is itself more easily movable.

  According to another characteristic of the invention, the robot arm carries a bundle of conductive cables and fluid conduits, connecting the means for supplying electrical energy, gas and cooling fluid to portions of connectors which are associated with the means for fixing a torch on the robot arm and which are intended to cooperate for example by interlocking with other parts of connectors mounted on the torches, so that the attachment of a torch on the robot arm simultaneously ensures the connection this torch means for supplying electrical energy, gas and cooling fluid.

  It is therefore sufficient, in the installation according to the invention, a single bundle of cables and conduits which is permanently carried by the robot arm, to feed the torches mounted in turn on the robot arm, this beam being advantageously fixed on the various elements of the robot arm and naturally following its evolutions.

  Each torch is automatically connected to this beam when it is mounted on the robot arm to be used, and is automatically disconnected when it is removed from the robot arm, which allows easy handling for maintenance and adjustment before a new use . In addition, each torch is fixable on the robot arm and removable from it, automatically without operator intervention.

  Typically, the duration of a change of torch on the robot arm is less than one minute and the duration of completion of a part can be reduced by half (for example for a particular part, 6:30 instead of 12:30).

  In one embodiment of the invention, the connector parts and the fixing means are carried by two plates integral with the robot arm and the torch respectively, and intended to be contiguous to each other for the fixation of the torch on the robot arm and the connection of the torch to the power supply means.

  The fixing means ensure the correct positioning of the torch on the robot arm and retain the torch even in case of failure of the power supply. They comprise, for example, a socket carried by a aforementioned plate and intended to be engaged in a cylindrical housing of the other plate, and resilient means, such as balls biased by springs, locking or elastic latching of the socket in the cylindrical housing.

  Conventionally, the connector parts are male and female parts respectively cooperating by interlocking to ensure the connection of a torch to the supply means.

  The bundle cables connected to the connector parts comprise, for example, video cables and cables for connection to control, regulation, coding and probing circuits.

  Each torch may comprise an intermediate terminal block mounted between the torch and its means of attachment and connection to the robot arm, for connecting additional means of measurement or control to this torch.

  The robot arm may carry means for supplying a welding filler wire, resulting in the above-mentioned fastening and connecting means of a torch.

  The installation also comprises means for supporting and positioning torches that are not used, and torch maintenance and adjustment means installed near these support and positioning means and outside the zone of evolution of the torch. robot arm.

  The torches are positioned on the support means, prior to the production of a part, in precise locations each corresponding to a torch of a specific type, that the robot arm can identify and identify for example through a 4-bit digital coding system. This allows the robot arm to be programmed to go to the predetermined location of a torch of a predetermined type, to check if this location is the intended one, and if a torch is present at that location and is of the desired type. , fixing the torch on the robot arm and its connection to the cable harness and ducts are then ensured by a translation of the end of the robot arm. The same operations are performed in reverse for the removal of the torch. The operator intervenes only to restore the torches after use and to make new torch adjustments in masked time, ie while welding operations are performed by the robot arm by means of the other torches available.

  In general, the installation according to the invention has the following advantages over known installations: a significant time saving in the production of the welded parts, thanks in particular to the automation of the assembly and disassembly of each torch on the robot arm, - a reduction in space and a significant improvement in the possibilities of movement of the robot arm, - the removal of the switch box which, in known installations, connected all the bundles of cables and conduits torches means power supply and selectively control the supply of one of these beams, and - increased security because the operator is no longer involved in the evolution area of the robot arm.

  The invention also relates to a connection plate and supply of a welding torch on a robot arm in an installation of the aforementioned type, characterized in that it comprises on one side means for fixing the welding torch on the robot arm and connectors for connecting the torch to means for supplying electrical energy, gas and cooling fluid.

  In one embodiment of the plate, the torch attachment means comprise a socket intended to be engaged in a cylindrical housing of a complementary plate, and resilient means, such as balls biased by springs, locking or elastic snap of the socket in the cylindrical housing.

  The plate may for example bear on one of its sides means 10 for feeding or guiding a welding filler wire.

  The plate advantageously comprises on its face carrying the fixing means, at least one projecting element intended to be housed in a corresponding orifice provided on the complementary plate when the relative positioning of the plates is correct, that is to say that the fastening means and the connectors of each plate are aligned with each other, a translation of a plate to the other plate sufficient to fix and connect the torch.

  The board may also comprise means for connecting a video cable and connecting cables to control, regulation, coding and probing circuits.

  The invention will be better understood and other details, characteristics and advantages of the present invention will appear more clearly on reading the following description given by way of non-limiting example with reference to the accompanying drawings, in which: FIG. very schematically a robotic arc welding system according to the prior art; FIG. 2 very schematically represents a robotic arc welding installation according to the invention; and FIGS. 3 and 4 show an embodiment of the means for fixing a welding torch on a robot arm and for connecting this torch to supply means.

  FIG. 1 shows a known robotic installation 10 for arc welding a workpiece 12, comprising a robot arm 14 for handling a welding torch, and three welding torches 16, 18 and 20, each of which is permanently connected by its own bundle 22 of conductive cables and fluid conduits to means for supplying torches with electrical energy, gas and cooling fluid.

  The torches 16, 18 and 20 used are, for example, TIG (Tungsten Inert Gas) arc welding torches and plasma welding torches and their supply means comprise sources 24, 26 and 28 of electrical energy. , cooling fluid such as water, and plasmagenic and protective gas such as argon, respectively.

  The robot arm 14 is for example of the six-axis type and comprises at one end suitable means for fixing one of the welding torches, the various torches 16, 18 and 20 being used in turn for the production of the cords. welding on the piece 12.

  The bundles 22 of cables and conduits have long lengths and are carried and guided by appropriate means on a bracket 29 or the like. They are connected to their power supply means by a switching box 30 which makes it possible to connect the torch 16 carried by the robot arm 14 to the power sources 24, 26 and 28 by means of adjustment means 32.

  The robotic arc welding system 40 according to the invention shown in FIG. 2 differs from the known technique essentially in that the robot arm 14 comprises at its free end means for fixing a torch 16 and connection of this torch to a bundle 42 of cables and conduits which are carried by the robot arm 14 and connected by the adjustment means 32 to the sources 24, 26 and 28 supplying electrical energy, gas and cooling fluid .

  The means for fixing and connecting the torch are carried by a plate 44 at the free end of the robot arm and a plate 46 at one end of the torch.

  The other two torches 18 and 20 that are not used are disconnected from the beam 42 and positioned at predetermined locations on support means 48 situated at the edge of the zone of evolution of the robot arm 14.

  Means 50 for maintenance and adjustment are installed near these support means 48, outside the zone of evolution of the robot arm 14, and allow an operator to intervene on the torches 18, 20 to change consumables and make adjustments to optimize the future use of these torches. During the maintenance and adjustment of the torches 18 and 20, the welding operations continue with the torch 16 carried by the robot arm.

  An embodiment of the plates 44 and 46 of the robot arm 14 and torches 16, 18, 20 is shown schematically in Figures 3 and 4.

  The plates 44 and 46 are substantially parallelepipedal and each comprise a flat face 52, 54, respectively, these faces 52, 54 being intended to be contiguous to one another and comprising the torch attachment means on the robot arm and the means for connecting this torch to the beam 42 mounted on the robot arm.

  The fastening means comprise, on the face 52 of the plate 44 of the robot arm, a cylindrical sleeve 56 whose axis 58 is perpendicular to the face 52, this sleeve 56 being intended to be engaged in a corresponding cylindrical housing 60 formed on the face 54 of the plate 46 of a torch.

  The bushing 56 comprises on its outer cylindrical surface elements such as balls 62 intended to cooperate by locking or resilient latching with a corresponding annular groove (not shown) formed in the inner cylindrical surface of the cylindrical housing 60.

  The balls 62 are housed in radial orifices formed on the outer cylindrical surface of the sleeve 56 and regularly distributed over the circumference of the sleeve. They are movable radially inwards in their orifices, to allow the engagement of the sleeve 56 in the cylindrical housing 60.

  Springs or the like, mounted in the holes for accommodating the balls, between the balls and the bottom of the orifices, bias the balls 62 radially outwardly, projecting from the cylindrical surface of the sleeve (FIG. 3), to come to the inside of the aforementioned annular groove of the cylindrical housing 60 and ensure the attachment of the torch on the robot arm.

  Means 64 for supplying and evacuating 66 pressurized air into the bores 62 housing holes are provided to control the movement of the balls in their housing orifices, these balls being sealingly mounted in these orifices.

  The torch fixed on the robot arm is connected to the beam 42 by means of connectors each having a male part and a female part which are respectively mounted on the plate 46 of the torch and on the plate 44 of the robot arm, or on their faces 52, 54 can be hitched together on adjacent surfaces of housings fixed on the sides of the plates.

  In the example shown, four male or female parts of connectors 68, 70 are mounted on the face 52 of the stage of the robot arm, next to the sleeve 56 and along one edge of the plate, and are connected to the supply sources 26, 28 of gas and cooling fluid, respectively, by conduits 72, 74 of the beam 42 which are fixed on this edge of the plate, substantially to the right of the corresponding connector parts.

  These connector parts 68, 70 are intended to cooperate by interlocking with four connector parts 69, 71 mounted on the face 54 of the torch plate, next to the housing 60 and along an edge of the plate 46, in the same way as the connector parts 68, 70 on the plate 52 of the robot arm.

  The connector portions 69 are connected by conduits 76 to shield gas ejection means at the weld bead to be produced in the case where the torch used is a TIG arc welding torch, and also to plasma gas ejection means in the case where the torch used is a plasma welding torch.

  The connector portions 71 are connected by conduits 78 to fluid circulation means in the torch for cooling.

  The connector portions 68 to 71 are advantageously equipped with non-return valves to prevent leakage of gas and coolant upon disconnection.

  Two electrical connection pins 80 are mounted on one side of a small housing 82 fixed to one side of the plate, that face of the housing 82 and the face 52 of the robot arm plate being parallel and at the same level, and are connected to each other. by conducting cables 84 to the source 24 of electrical energy.

  These pins 80 are intended to cooperate by interlocking with two connection passages 81 formed in a corresponding face of a housing 86 similar to the housing 82 carried by the robot arm and fixed on one side of the plate 46 of the torch to be attached to the housing 82 of the robot arm.

  The connection passages 81 are connected by electrical conductors to an electrode of the welding torch. The intensity of the electrical supply current of the torch is for example 300 amperes for welding.

  The plate 44 of the robot arm also carries on another of its sides two other housings or terminal blocks 88 each having on a face parallel to the face 52 of the plate 44, a connector 90, 92 male or female with several pins connected by cables 94 of the beam for example to control circuits, regulation, coding and probing.

  Two connectors 91, 93 female or male respectively are mounted on housings or similar terminal blocks 96 arranged on a corresponding side of the plate 46 of the torch, and are connected by conductors for example to probing means to determine the position of the torch relative to the workpiece, and means for measuring and controlling, in particular, the voltage of the welding electric arc or the pilot arc in the case of plasma welding, etc. The face 52 of the stage of the robot arm still carries a connector 98 located between the socket and one of the housings 88 of the plate and which is connected by a video cable 100 fixed on one side of the plate opposite the housing 82 to means of recording and viewing. This video connector 98 cooperates by interlocking with a video connector 99 complementary to the face 54 of the torch plate, which is connected by conductors 102 to a video camera carried by the torch. The conductors 102 are fixed on the side of the plate 46 opposite the housing 86.

  Means 104 for feeding a welding filler wire at the level of the weld bead to be produced are carried by the plate 44 of the robot arm on the side where the video cable 100 is fixed and cooperate with means 106 of FIG. guiding the filler wire provided on the side of the plate 46 of the torch where the video conductors 102 are fixed.

  To ensure correct alignment between the axes of the bushing 56 and the cylindrical housing 60 and correct angular positioning between the plates 44, 46 so that the connectors and feeder wire guide means are axially aligned with each other. with each other, the plate 44 of the robot arm has on its face 52 two guide rods 108 disposed on either side of the sleeve 56, and intended to be engaged in corresponding holes 110 of the face 54 of the plate 46 of the torch.

  When a part to be produced requires, among other things, the successive use of a TIG arc welding torch and a plasma welding torch, the robotic welding installation according to the invention is used as follows : The robot arm is programmed to go to a known location of a TIG arc welding torch on the support and positioning means 48. Before the sleeve 56 carried by the robot arm is engaged in the cylindrical housing 60 of the plate 46 of the torch, and the connectors of the plates are nested mutually into each other, the robot arm verifies by a digital coding system four-bit if the torch present is a TIG arc welding torch. If this is the case, the plates of the torch and the robot arm are contiguous, the connectors are nested within each other and the balls 62 are engaged in their housings to fix the torch on the robot arm and connect it to the beam 42 cables and conduits of the robot arm. The latter can perform various welding operations by means of the torch.

  When a plasma welding torch is to be used in place of the TIG arc welding torch, it is brought back and deposited on the support means in its original position, and the robot arm is directed to the known location of a plasma welding torch and verify that the torch present at this location is the one provided. If this is the case, the robot connects to the torch and uses it to continue the realization of the piece. The adjustment means 32 are then controlled for the supply of plasma gas torch.

  If the verification is incorrect, an error message may be transmitted to an operator and the robot arm is directed to another known location of a plasma welding torch and verifies whether the present torch is of the desired type.

  When the torch is not exactly in a good angular position on the support means, the robot arm rotates the plate 44 about the axis 58 of the sleeve until the guide rods 108 of the plate of the robot are well aligned with the orifices 110 of the platen of the torch and can engage in them.

Claims (14)

  1. An arc welding apparatus, comprising welding torches (16, 18, 20) of different types, means (24, 26, 28) for supplying torches with electrical energy, gas and fluid. cooling, and a robot arm (14) having at one end means for fixing one of the aforementioned torches, characterized in that the means for fixing a torch (16) on the robot arm comprise connection means of this torch (16) means (24, 26, 28) for supplying electrical energy, gas and cooling fluid.   2. Installation according to claim 1, characterized in that the robot arm (14) carries a bundle (42) of conductive cables and fluid conduits, connecting the means (24, 26, 28) for supplying electrical energy, of gas and cooling fluid to connector parts (68, 70, 80, 90, 92, 98) associated with the means for attaching a torch to the robot arm and intended to cooperate by interlocking with other parts of connectors (69, 71, 81, 91, 93, 99) mounted on the torches (16, 18, 20), so that the attachment of a torch to the robot arm (14) simultaneously provides the connection of this torch to the means (24, 26, 28) for supplying electric energy, gas and cooling fluid.   3. Installation according to claim 2, characterized in that the connector parts and the fixing means are carried by two plates (44, 46) integral with the robot arm (14) and the torch respectively, and intended to be contiguous l to one another for fixing the torch to the robot arm (14) and connecting the torch to the supply means (24, 26, 28).   4. Installation according to claim 3, characterized in that the fixing means comprise a sleeve (56) carried by a plate (44) and intended to be engaged in a cylindrical housing (60) of the other plate (46), and elastic means, such as balls (62) biased by springs, locking or elastic snap-fitting of the sleeve (56) in the cylindrical housing (60).   5. Installation according to one of claims 2 to 4, characterized in that said connector parts are male and female parts respectively, cooperating by interlocking to ensure the connection of a torch means (24, 26, 28). power.   6. Installation according to one of claims 2 to 5, characterized in that the beam cables (42) connected to said connector parts (90, 92, 98) comprise video cables and connecting cables to control circuits , regulation, coding and probing.   7. Installation according to one of the preceding claims, characterized in that each torch (16, 18, 20) comprises an intermediate terminal block mounted between the torch and its fixing means and connection to the robot arm (14), for the connecting additional means of measurement or control to this torch.   8. Installation according to one of the preceding claims, characterized in that the robot arm (14) also carries means (104) for supplying a welding filler wire, resulting in the aforementioned fixing and connecting means a torch.   9. Installation according to one of the preceding claims, characterized in that it comprises means (48) for supporting and positioning torches (18, 20) not used, and means (50) for maintenance and adjustment of torches, installed near these means (48) of support and positioning and outside the area of evolution of the robot arm (14).   10. Plate for connecting and supplying a welding torch on a robot arm in an installation of the type described in one of Claims 1 to 9, characterized in that it comprises on one face (52, 54) means (56, 60, 62) for attaching the welding torch to the robot arm and connectors (68 to 71, 80, 81, 90 to 93, 98, 99) for connecting the torch to means for supply of electrical energy, gas and cooling fluid.   11. Platinum according to claim 10, characterized in that the fastening means of the torch comprise a sleeve (56) intended to be engaged in a cylindrical housing (60) of a plate (46) complementary, and elastic means, such as balls (62) biased by springs, locking or snap elastically of the sleeve (56) in the cylindrical housing (60).   12. Platinum according to claim 10 or 11, characterized in that it carries on one of its sides means (104, 106) for feeding or guiding a welding filler wire.   13. Platinum according to one of claims 10 to 12, characterized in that it comprises on its face (52, 54) carrying the fixing means, at least one projecting element (108) intended to be housed in a corresponding orifice (110) provided on a complementary plate (46) when the relative positioning of the plates is correct.   14. Platinum according to one of claims 10 to 13, characterized in that it also comprises means for connecting a video cable and connecting cables to control circuits, regulation, coding and probing.