FR3077518A1 - MULTIPURPOSE PREHENSER OF BODY PARTS - Google Patents

Abstract

The invention relates to a multipurpose gripper (1) for gripping a bodywork part (3), the gripper (1) comprising a frame (5) from which extends laterally at least one arm (9), the gripper ( 1) being remarkable in that at least one arm (9) is rotatable about its longitudinal axis, and in that said arm (9) carries at least two gripping tools (13) angularly distributed, so that that rotation of said arm places at least one of the gripping tools (13) in the active position and at least one other gripping tool (13) in the passive position.

Description

VERSATILE BODY PIECE GRIPPER

The invention relates to the tooling of assembly lines for bodywork components, for example intended to equip factories for the manufacture of motor vehicles. In particular, the invention relates to a gripper for bodywork elements, such as door panels for motor vehicles.

In assembly lines, body parts are moved between different positions by manipulator robots. These robots include an arm at the end of which is attached a gripper, configured to hold a part for its movement. Said grippers can, for example, comprise a support structure in the form of a tube on which are mounted various gripping tools positioned on either side of the support structure specifically for the part to be worn. However, on the same assembly line, several silhouettes of vehicles can be produced, which implies carrying out a change of gripper at the level of the robot manipulator when passing from one silhouette to another. Although rapid, these tool changes take minimal time which limits production rates. There is therefore a need for a versatile gripper which can adapt to different vehicle shapes for a given bodywork part such as, for example, a door panel, so that it is no longer necessary to change the gripper in the robot's hand when changing the silhouette of the vehicle to be produced.

The document FR2441461 proposes a mechanism for changing the workpiece in a machine tool, comprising a shuttle movable in the longitudinal direction of the lathe, a carriage movable vertically according to the shuttle and, arranged on this carriage and rotating about a horizontal axis, a gripper means on which two pairs of jaws are horizontally displaceable in parallel with said shaft and on opposite sides thereof, the first pair of jaws being intended to supply the machine tool with parts to be mounted between centers or on mandrel, and the second pair being intended to deliver parts from the machine tool.

Document US8920107 proposes a device for gripping a substrate with four contact positions with the substrate.

The known devices all have advantages, but still lack adaptability and versatility, so that there remains a need to improve existing systems.

The invention aims to respond to at least one of the disadvantages presented by the prior art by providing a versatile gripper which can be used on body parts of different sizes or different shapes such as, for example, panels of door belonging to silhouettes of different vehicles.

To this end, the subject of the invention is a versatile gripper for gripping a bodywork part, the gripper comprising a frame from which extends at least one arm laterally, the gripper being remarkable in that at least one arm is movable in rotation along its longitudinal axis, and in that said arm carries at least two gripping tools angularly distributed, so that the rotation of said arm places at least one of the gripping tools in the active position and at least one other gripping tool in passive position. As will have been understood on reading the definition which has just been given thereof, the invention consists in proposing a hand capable of taking at least two panels of different shapes and / or dimensions by means of gripping tools adapted to their specific silhouettes and which are carried by the same gripper. The gripper carries various tools which can be placed either in the active position for their use, or in the passive position for their storage. The gripper according to the invention is remarkable in that it carries the gripping tools of different shapes at all times, and is configured to be able to select those to be used at a given time. It is therefore no longer necessary to change the gripper between two silhouettes of vehicles. The tool change is made by rotation of the gripper arm (s) on themselves. The invention makes it possible to make precise, flexible and repeatable, the taking of different door panels and this with a single equipment. The invention thus makes it possible to dispense with changes in grippers, greedy in cycle time and costly. The invention guarantees a rapid change of silhouette.

Preferably, the frame carries a docking interface with a robot hand. According to a preferred embodiment, the gripping tools are carried by said arm by means of a barrel integral in rotation with said arm. Said barrel forms an interface for fixing and adjusting the various gripping tools carried.

Preferably, at least one gripping tool is a vacuum suction cup. Advantageously, at least one rotary arm further carries a distribution block intended to distribute the suction flow towards the vacuum suction cup placed in the active position. Preferably, at least one of said distribution blocks is integral in rotation with the arm which carries it.

According to a preferred embodiment, the gripper is intended to be connected to a vacuum generator and comprises means for connecting said vacuum generator to at least one distribution block. Said connection means are movable in translation by means of a connection system, so that they can be placed in a connection position in which the connection means are connected to at least one distribution block and a disconnection position in which they are removed from the distribution block (s) and therefore disconnected.

The invention is remarkable in that, when the gripping tools are vacuum suction cups, it provides a system for connecting said suction cups to a vacuum generator allowing the suction flow to be distributed in a simple and secure manner by eliminating the problems of twisting the suction pipes of the suction cups during the rotation of the arm (s). The invention maintains a positioning of the suction cups which is perpendicular to the sheet, which guarantees precise and repeatable grip. Each arm carries a plurality of vacuum cups, but only one is used at a time. The other suction cup (s) are "stored" on the barrel for future use on another vehicle silhouette. The storage of other suction cups on the barrel does not disturb the grip of the desired part. The use of a barrel makes the whole compact and facilitates the handling of several grippers by the same robot.

According to a preferred implementation of the invention, the gripper further comprises a locking device for fixing a movable arm in rotation, according to a given angular position. Preferably, the locking device comprises a ring mounted integral in rotation on said arm and showing orifices and a locking finger movable in translation and configured to be inserted in one of the orifices for the purpose of locking said arm according to a given angular position. .

Advantageously, the multipurpose gripper comprises a connection system having a plate movable in translation and carrying both means for connection to a vacuum distributor and a locking finger of the locking device. Preferably, said plate is associated with at least one spring, so that the unlocking of at least one arm and the disconnection of the connection means takes place against the elastic restoring forces of the said spring or springs.

According to a preferred embodiment, the versatile gripper comprises a system for rotating at least one arm along its longitudinal axis comprising at least one jack connected to a belt by means of a coupling piece, preferably the belt is connected to two axes, each axis forming one or two arms.

According to an embodiment which can be complementary to the previous one, the versatile gripper comprises a system for rotating at least one arm along its longitudinal axis comprising two jacks mounted in tandem, the stroke of a first jack being less than the stroke of the other jack, and one of the jacks being movably mounted on a carriage actuated by the other jack.

Optionally, the gripper further comprises a ball bushing system and the carriage on which one of the jacks is mounted and / or the coupling piece of the belt is guided in linear translation by said ball bushing system. .

According to a variant, at least two gripping tools are distributed along the length of the same arm. It is understood that said tools also have an angular distribution relative to one another around said arm.

According to a preferred variant which can be complementary, at least two arms are aligned in the transverse direction of the frame and are formed by the same axis crossing said frame right through in its transverse direction.

According to a second aspect, the invention relates to a method of implementing a versatile gripper according to the first aspect, said gripper comprising a frame from which extends laterally at least one arm, the gripper comprising at least one movable arm in rotation along its longitudinal axis, and said arm carrying at least two gripping tools distributed angularly, the method being remarkable in that it comprises a step of selecting a gripping tool by rotation of at least one arm.

The invention will be well understood and other aspects and advantages will appear clearly on reading the following description, given by way of example with reference to the drawing boards in which:

Figure 1 shows a gripper according to the invention, seen from above, in position on a bodywork element.

Figure 2 shows a gripper according to the invention, seen from below.

Figures 3 and 4 illustrate the vacuum distribution blocks of vacuum cups.

Figure 5 illustrates the vacuum distribution system of vacuum cups.

Figure 6 illustrates the system for rotating the arms.

In the description which follows the term "include" is synonymous with "include" is not limiting with regard to the presence of other elements in the gripper. It is understood that the term "understand" includes the terms "consist of". In the various figures, the same references designate identical or similar elements. The terms "lower" and "upper" relating to body parts such as door panels relate to the general orientation that the part will take once mounted in the vehicle. Thus, "lower" will designate a greater proximity to the ground than "higher" along a vertical axis.

Reference will firstly be made to FIG. 1 showing a gripper 1 according to the invention in position on a bodywork element 3, for example a door panel. The gripper 1 comprises a frame 5, preferably carrying a docking interface 7 with a robot hand. According to the invention, the frame 5 carries at least one arm 9 extending laterally from said frame 5. The or at least one of the arms 9 is movable in rotation along its longitudinal axis (ie the longitudinal axis of said arm) and carries a barrel 11 on which are fixed at least two gripping tools 13. The barrel 11 is integral in rotation with the arm 9 and forms a fixing interface for the gripping tools 13. In this way, at least two gripping tools 13 are distributed angularly around the axis of rotation of said arm 9. For example, the gripping tools 13 can be arranged so as to present an angle between them of 90 ° and 180 °. According to the invention, each arm 9 can carry two or at least two gripping tools 13, preferably each arm carries three or at least three gripping tools 13, more preferably still four or at least four gripping tools 13. When four gripping tools 13 are carried by the barrel 11 and distributed angularly around the longitudinal axis of said arm 9, the latter are advantageously arranged to have an angle of 90 ° between them.

According to a preferred implementation of the invention, at least two gripping tools 13 are further distributed along the length of said barrel 11, and therefore along the length of said arm 9, so that a first tool gripping 13 is spaced from the frame by a distance greater than the spacing distance of a second gripping tool 13.

Thus, the arm (s) 9 have the function of a rotary magazine, and of a tool change station. The gripping tools 13 can be placed alternately in the active position in which they can be used for gripping bodywork elements 3, or in a passive position in which the gripping tools 13 are unused and unusable for gripping bodywork elements. bodywork 3. The transition from the active position to the passive position of the gripping tools 13 carried by an arm 9 is effected by rotation of said arm 9 about its longitudinal axis.

The gripping tools can be of all types, for example magnets. However, according to a preferred implementation of the invention illustrated in FIG. 2, at least one gripping tool 13 is a vacuum cup. Preferably, all of the gripping tools 13 are vacuum suction cups 13.

When a rotary arm 9 comprises at least one vacuum cup 13, the latter is advantageously equipped with a distribution block 15 configured to distribute the suction flow towards the vacuum cup 13, if and only if it is placed in active position. This or these distribution blocks 15 are mounted in the frame 5 and integral in rotation with the rotary arms 9. For example, they are linked in rotation by means of a key. Thus the rotation of an arm 9 causes the distribution block 15 which is associated with it to rotate. An example of a distribution block 15 which can be used according to the invention is illustrated in FIGS. 3 and 4. Said block 15 advantageously has a cylindrical front part 17 intended to pass through the frame and a rear part 19 which can be formed of a straight prism or which can be cylindrical. Supply channels 21 are open on the base 23 of the front part 17, and open on the sides 25 of the rear part 19.

This configuration is advantageous in order to avoid kinking of the suction pipes associated with each of the vacuum cups 13 during the rotation of the arms 9. Each of the vacuum cups 13 is connected by a suction pipe (not shown) to one of the supply channels 21 of the distribution block 15 dedicated to it at the level of the base 23 of the front part. It is understood that the simultaneous rotation of the arm 9 and of the associated distribution block 15 avoids kinking of the pipe connecting a gripping tool 13 given to one of the supply channels 21 of said distribution block 15 since all of these elements are linked in rotation.

According to the invention, each supply channel 21 passes through the body of the distribution block 15 and is arranged to open on one of the sides 25 of the rear part 19 of said distribution block 15. The rear mouths 27 of the various supply channels 21 are distributed angularly in the same way as the gripping tools 13 around the longitudinal axis of the rotary arm 9.

Referring to FIG. 5, it is understood that during a tool change, the rotary arm or arms 9 are actuated so as to put the selected gripping tool 13 (for example, the vacuum cup) on each arms 9 in the active position, and that the rotation of the arm (s) 9 generates the rotation of each of the distribution blocks 15 which is associated with them so as to place the mouth 27 rear of the supply channel 21 associated with the suction cup to vacuum 13 placed in the active position opposite connection means 29 to a vacuum generator (not shown), for example a connection suction cup 29.

Said connection means 29 are advantageously connected to a vacuum generator and mounted on a system 31 of mobile connection in translation. The translational movement will alternately place the connection means 29 in the connection position in which the connection means 29 are connected to the distribution blocks 15, or in the disconnection position in which the connection means are spaced from said distribution blocks 15 and therefore disconnected. When the connection means 29 comprise connection suction cups, said connection means are connected to the connection block by pressing said suction cups against said distribution blocks 15, so that each suction cup circumvents the rear mouth 27 of the channel power supply associated with the gripping tool arranged in the active position. Placing the connecting means 29 in the disconnected position allows the distribution block 15 to rotate for a tool change. The connection system 31 comprises for example motors or jacks, for setting in motion the connection means 29.

According to a preferred implementation of the invention, the angular position of the rotary arms 9 is fixed by a locking device (33, 35) outside the operations of rotating said arms 9 with a view to changing the tool 13. The locking device (33, 35) can be in the form of a ring 33 carrying a series of orifices 37 distributed angularly along its outer cylindrical surface and corresponding to the different angular positions that the arm 9 can adopt to place the tools for gripping 13 in active position. It further comprises a finger 35, which penetrates one of said orifices 37 in order to fix the position of the ring 33 and therefore to prevent any unwanted rotation of said arm 9. The finger (s) 35 are advantageously movable in translation between their locking position and their unlocking position. The locking finger or fingers are advantageously associated with one or more return springs (not shown) configured to return them to the locked position.

According to a preferred embodiment, at least one finger 35 is mounted on a connection system 31 allowing the connection of the connection means 29. The connection system 31 then shows a double function allowing both the connection of the gripping tools 13 active in the vacuum generator and locking in position of the arm (s) 9. For this purpose, the connection system will advantageously have a plate 39, movable in translation in the longitudinal direction of the frame 5, and carrying both connection means 29 to a vacuum generator and at least one locking finger 35. As seen above, the movement of the plate 39 is ensured by jacks or by a motor. Preferably, said plate 39 is associated with at least one spring (not shown), so that the unlocking of at least one arm 9 and the disconnection of the connection means 29 takes place against the restoring forces. elastic of the said spring or springs.

According to a preferred implementation, at least two arms 9 are aligned in the transverse direction of the frame 5 and are formed by the same axis passing through said frame 5 right through in its transverse direction. Also, the gripper 1 has a single locking device (33, 35) for two arms 9. Preferably, the gripper 1 comprises four arms 9 formed by two axes. It then preferably comprises two locking devices (33, 35), each being associated with an axis. Advantageously, it comprises two connection systems 31 of the connection means 29, preferably associated with the locking devices (33, 35). Said connection systems 31 are arranged at the ends of the frame

5.

The rotation of the arms 9, that is to say of each arm individually or of the axes when the arms 9 are connected two by two by means of axes, can be done by any means and for example by using a electric motor.

However, according to a preferred embodiment of the invention shown in FIG. 6, the arms 9 are rotated by means of at least one jack (41, 43). To this end, at least one arm 9 and / or at least one axis forming two arms 9 comprises a pulley 45 receiving a toothed belt 47. When the two arms 9 are formed by the same axis, the pulley 45 is advantageously placed centrally. When the gripper 1 comprises several axes, the same belt 47 will advantageously be connected to the different pulleys 45 mounted on said axes so that the movements of the different axes are synchronized. In the illustrated embodiment, the gripper 1 has two axes forming four arms 9. However, those skilled in the art will easily adapt the invention to grippers showing more than two axes, said axes forming, depending on the case, one or two arms.

When, according to an embodiment not shown, each arm carries only two gripping tools, so that the arms must be positioned at two different angular positions for a tool change, only one cylinder is necessary.

When the rotary arm (s) 9 each carry three or four gripping tools 13, so that said arms 9 must be able to be rotated in order to be able to be placed according to three or four different angular positions, the arms 9 will be rotated advantageously by a rotation system comprising two jacks (41,43) mounted in tandem, according to an arrangement known to those skilled in the art. In this arrangement the two jacks (41, 43) have different strokes, the stroke of one jack 43 advantageously being twice the stroke of the other jack 41. A first jack 41 is mounted on a carriage 49 and is movable in translation in the longitudinal direction of the frame 5 under the action of the second cylinder 43 which is connected to said carriage 49. The first cylinder 41 is connected to the belt 47 by a coupling piece 51. According to an advantageous implementation, the carriage 49 on which one of the jacks (41, 43) and / or the coupling piece 51 of the belt 47 is mounted is guided in linear translation by a ball bushing system.

According to a preferred embodiment, the gripper 1 further comprises at its ends a fall arrest device for parts visible in FIGS. 1 and 2, composed of two clamping elements 53 movable by pivoting between an open position and a closed position, each clamping element 53 comprising at least one support piece 55. In the figures they are shown in the open position. Once in the closed position, the clamping elements 53 maintain the bodywork part 3 by the gripper 1 in the event of the suction suction vacuum 13 being cut off, preventing said bodywork parts from falling.

The robot equipped with a gripper according to the invention, comprising four gripping tools per arm for gripping four pieces of different shapes (A, B, C and D) is used as follows. In the initial state, the robot is in the fallback state. The line controller gives the code of the part to be taken (A, B, C or D). The connection system disengages by retracting the associated cylinders, which disconnects the suction circuit and unlocks the axes of rotation of the arms. The rotation of the arms is then controlled. Said rotation is done in one of three 90 ° steps allowed by the mounting of the two cylinders in tandem so as to put the selected gripping tools in the active position. The connection system is re-engaged by advanced cylinders, which allows the connection of the suction cups in the active position with vacuum distributor and the locking of the arms according to a given angular position.

The robot then moves to a store to pick up a part, it is positioned on the part and activates the vacuum distributor to grab said part. Once the part is lifted, the fall arrest system is put in place and the part is moved to its destination, for example a wedding tool.

Also, the invention also relates to a method of implementing a versatile gripper 1 as described in the present specification, said gripper 1 comprising a frame 5 from which extends at least one arm 9 laterally, the gripper 1 comprising at least at least one arm 9 movable in rotation along its longitudinal axis, and said arm 9 carrying at least two gripping tools 13 distributed angularly, the method being remarkable in that it comprises a step of selecting a gripping tool 13 by rotation at least one arm

9.

Preferably, the gripping tool 13 is a vacuum cup and the method comprises a step of disconnecting the connection means 29 to the vacuum generator from at least one distribution block 15 carried by an arm 9 before the rotation step of said arm 9. Preferably also, the gripping tool 13 is a vacuum suction cup and the method comprises a step of connecting the connection means 29 to the vacuum generator to at least one distribution block 15 carried by an arm 9 after the step of rotating said arm 9.

Claims (10)

1. Multipurpose gripper (1) for gripping a bodywork part (3), the gripper (1) comprising a frame (5) from which laterally extends at least one arm (9), the gripper (1) is characterized in that at least one arm (9) is movable in rotation along its longitudinal axis, and in that said arm (9) carries at least two gripping tools (13) distributed angularly, so that the rotation said arm places at least one of the gripping tools (13) in the active position and at least one other gripping tool (13) in the passive position. 2. Multipurpose gripper (1) according to claim 1, characterized in that at least one gripping tool (13) is a vacuum suction cup (13), preferably at least one rotary arm (9) further carries a block distribution (15) intended to distribute the suction flow towards the vacuum suction cup (13) placed in the active position, preferably at least one of said distribution blocks (15) is rotationally integral with the arm (9) which carries it . 3. Multipurpose gripper (1) according to claim 2, characterized in that it is intended to be connected to a vacuum generator and in that it comprises connecting means (29) of said vacuum generator to at least one distribution block (15), said connection means (29) being movable in translation by means of a connection system (31), so that it can be placed in a connection position in which the connection means (29 ) are connected to at least one distribution block (15) and a disconnection position in which they are separated from the distribution block (s) (15) and therefore disconnected. 4. Gripper according to one of claims 1 to 3, characterized in that it further comprises a locking device (33, 35) for fixing an arm (9) movable in rotation, according to a given angular position , preferably the locking device (33, 35) comprises a ring (33) rotatably mounted on said arm (9) and showing orifices (37) and a locking finger (35) movable in translation and configured to s 'Insert into one of the holes (37) for locking said arm (9) at a given angular position. 5. Gripper (1) versatile according to claims 3 and 4 characterized in that it comprises a connection system (31) having a movable plate in translation and carrying both connecting means (29) to a vacuum distributor and a locking finger of the locking device (33, 35), preferably said plate is associated with at least one spring, so that the unlocking of at least one arm (9) and the disconnection of the connection means (29) is made against the elastic return forces of the said spring or springs. 6. Multipurpose gripper (1) according to one of claims 1 to 5, characterized in that it comprises a system for rotating at least one arm (9) along its longitudinal axis comprising at least one jack (41 , 43) connected to a belt (47) by means of a coupling piece (51), preferably the belt (47) is connected to two axes, each axis forming one or two arms (9). 7. Multipurpose gripper (1) according to one of claims 1 to 6, characterized in that it comprises a system for rotating at least one arm (9) along its longitudinal axis comprising two jacks (41,43 ) mounted in tandem, the stroke of a first cylinder (41) being less than the stroke of the other cylinder (43), and one of the cylinders (41, 43) being movably mounted on a carriage (49) actuated by the other cylinder. 8. Multipurpose gripper (1) according to one of claims 6 or 7, characterized in that the gripper further comprises a ball bushing system and in that the carriage (49) on which is mounted one of the cylinders (41, 43) and / or the coupling piece (51) of the belt (47) are guided in linear translation by said ball bushing system. 9. Multipurpose gripper (1) according to one of claims 1 to 8 characterized in that at least two gripping tools (13) are distributed along the length of the same arm (9) and / or in that at least two arms (9) are aligned in the transverse direction of the frame (5) and are formed by the same axis passing through said frame (5) right through in its transverse direction. 10. A method of implementing a multi-purpose gripper (1) according to one of claims 1 to 9, said gripper (1) comprising a frame (5) from which laterally extends at least one arm (9), the gripper comprising at least one arm (9) movable in rotation along its longitudinal axis, and said arm (9) carrying at least two gripping tools (13) distributed angularly, the method being characterized in that it comprises a selection step a gripping tool (13) by rotation of at least one arm (9).