WO2008031946A1

WO2008031946A1 - Workstation for positioning parts as a background task

Info

Publication number: WO2008031946A1
Application number: PCT/FR2007/001482
Authority: WO
Inventors: Daniel Demit; Fabrice Legeleux; François Malatier
Original assignee: Abb France
Priority date: 2006-09-14
Filing date: 2007-09-13
Publication date: 2008-03-20
Also published as: FR2905888B1; FR2905888A1

Abstract

Station for fixing a first part (A) and a second part (B) to a third part (C), comprising a fixing unit (6), a unit (2) for positioning the third part, a robot (5) for positioning the first and second parts on the third part, and a control unit (10) to cause: the positioning robot to position the first part on the third part; the fixing unit to fix the first part to the third part; the positioning robot to release the first part when fixing is sufficiently advanced to freeze the position of the first part on the third part; the positioning robot to position the second part on the third part during the end of the fixing of the first part; and the fixing unit to fix the second part.

Description

Workstation providing parts positioning in masked time.

The present invention relates to a robotic work station and more particularly to a station for fastening parts such as body elements of a motor vehicle. BACKGROUND OF THE INVENTION

There are known fixing stations of a first part and a second part on a third part, comprising a positioning unit and a fixing unit connected to a control unit. The positioning unit comprises a support for the third part and two tilting arms arranged to be able to position the first and second parts on the third part. Tilt arms can be cumbersome when attaching parts, for example because of the risk of interference with the moving unit. Such a station is also not very flexible.

However, users of such workstations generally have a need for productivity and profitability, that is to say, to make the most of the workstations and the elements that compose them, and flexibility so that the stations They can be easily adapted to different types of parts, different speeds and changes in the manufacturing process, but this need for flexibility must not be met at the expense of profitability.

OBJECT OF THE INVENTION

An object of the invention is to provide a workstation to meet at least partly the above stated needs.

SUMMARY OF THE INVENTION

For this purpose, there is provided, according to the invention, a station for fixing a first part and a second part on a third part, comprising a fixing unit, a positioning unit of the third piece, a robot for positioning the first and second pieces on the third piece and a control unit arranged to control: the positioning robot for positioning the first piece on the third piece,

- the fixing unit to fix the first part on the third part,

the positioning robot for positioning the second piece on the third piece,

- the fixing unit to fix the second part.

This station is very versatile and allows quick linking of fixing operations by minimizing the necessary material resources. Preferably, the control unit is arranged to control the positioning robot to release the first piece when the attachment is sufficiently advanced to freeze the position of the first piece on the third piece, the positioning of the second piece on the first piece. third piece being realized while the fixing of the first piece continues.

Thus, the positioning of the second part is performed in masked time, during the completion of the fixing of the first part, so that the fixing unit can, from the completion of the first part, go without dead time to fixing the second piece. In addition, when the first and second pieces are at least a little spaced apart on the third, the positioning of the second piece allows the positioning robot to clear the area of the first piece, thus facilitating access thereto. by the fixing unit.

Advantageously, the control unit is arranged to control: the positioning robot to release the second piece when the attachment is sufficiently advanced to freeze the position of the second piece,

- the positioning robot so that it goes to look for a new first part during the end of fixing of the second part and,

- Preferably, the positioning robot to also fetch a new second part during the end of the attachment of the second part mounted on third piece. Dead time is still limited by performing masked loading of the first and second parts on the positioning robot. Access to the first and second parts by the fixing unit is also released. According to a particular embodiment, the positioning robot is equipped with a support having receiving locations of the first part and the second part and, preferably, the support has two distinct faces each provided with one of the ments.

Thus, the positioning robot does not have to look for a second part after the attachment of the first part, so that it can immediately after the attachment of the latter position the second part. This is particularly advantageous when the attachment of the first part is fast and does not allow time for the positioning robot to go and find a second part and position it.

Other features and advantages of the invention will become apparent from reading the following description of a particular non-limiting embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made to the appended drawings, among which: FIG. 1 is a schematic view of a station according to a first embodiment,

- Figure 2 is a schematic view of a station according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

The station according to the invention is arranged to fix a first piece A and a second piece B on a third piece C.

With reference to FIG. 1, the work station, generally designated 1, comprises a support for the workpiece C, here represented in the form of a conveyor 2 making it possible to enter in the station 1 the workpiece C and remove from the station the part C on which are fixed parts A and B. The loading and unloading of the parts C on the conveyor 2 are for example made by a robot or an operator. Chargers 3 and 4 supply the station respectively in parts A and B. Chargers 3 and 4 are known in themselves and may consist of conveyors, robots, parts stores (as in this case) ... or be replaced by an operator.

Station 1 also comprises a fixing unit and a positioning robot 5.

The fixing unit is here a welding robot 6 known in itself. The welding robot 6 is here equipped with a laser head but may also be provided with an electric welding clamp. Other fixing methods are of course conceivable, such as gluing, stapling, crimping, screwing, etc. The positioning robot 5 comprises an arm having a free end equipped with a support 7 comprising two distinct faces provided with respectively of a location 8 for receiving a workpiece A and a location 9 for receiving a workpiece B. Each location 8, 9 is provided with means for holding the corresponding workpiece. dante. The faces are here opposite and parallel to an axis of the support 7, the support 7 being pivotally mounted about this axis on the arm of the positioning robot 5. The support 7 may also comprise more than two faces or on the contrary a single face.

The conveyor 2, the loaders 3, 4, the positioning robot 5 and the welding robot 6 are connected to a control unit 10 to be controlled by it. The control unit 10 comprises, in a manner known per se, computer means arranged to execute a control program for the implementation of a method for fixing the pieces A and B on the piece C.

The operations whose realization is controlled by the control unit 10 according to the control program will now be detailed.

The positioning robot 5 starts by searching for pieces A and B in the loaders 3 and 4 so that the pieces A and B are held in the locations 8 and 9 of the support 7. Simultaneously, the conveyor 2 brings a piece C and put it in position.

The positioning robot 5 presents the piece A opposite the piece C and positions the piece A on the piece C.

The welding robot 6 then starts fixing the piece A on the piece C.

When the attachment is advanced enough to freeze the position of the workpiece A on the workpiece C, the positioning robot 5 releases the workpiece A.

The positioning robot 5 then presents the piece B opposite the piece C and positions the piece B on the piece C during the end of the fixing of the piece A on the piece C.

Once the fixing of the piece A is completed, the welding robot 6 begins fixing the piece B on the piece C. When the attachment of the piece B on the piece C is advanced enough to freeze the position of the piece B on the piece C, the positioning robot 5 releases the piece B and fetches a new piece A and a new piece B while the fixing of the piece B on the piece C ends.

The positioning robot 5 is arranged to receive a plurality of supports 7 allowing the assembly of a greater variety of parts. The connection / disconnection means of the support and the positioning robot 5 are known per se. The station thus comprises a magazine 13 of supports 7.

Alternatively, as shown in Figure 2, the conveyor 2 can be replaced by a robot 12 and the welding robot 6 can be replaced by a fixed head 11, in this case a laser welding head. The fixed head 11 may have a degree of freedom allowing angular movement.

The support robot 12 and the positioning robot 5 move in a coordinated manner so as to move the point of impact of the laser beam of the fixed head 11 along the attachment zones of the pieces A and B on the piece C.

Of course, the invention is not limited to the embodiment described and variants may be provided without departing from the scope of the invention as defined by the claims.

It can thus be provided on each side of the support

7 is a place for receiving a room A and a room for receiving a room B. It is then possible while the rooms A and B of a side are being fixed on the room C , to load new pieces A and B on the opposite side of the coin C, or to load parts A and B simultaneously on both sides in order to perform this loading only both parts C.

When the fixing operations are relatively long, the positioning robot has time to fetch a new part as soon as it has dropped one so that the loading of the positioning robot is performed as and when unloading . The support 7 can in this case in particular be replaced by a gripping hand arranged to grasp alternately a part A and a part B. It goes without saying that the two embodiments described can be combined.

In addition, it is possible to arrange the station to allow the attachment of more than two parts, for example by multiplying the number of positioning robots or the number of locations available on the support thereof.

The conveyor 2 may comprise a mobile support for moving the workpiece in at least one transverse horizontal direction to the conveyor 2 for example to move the workpiece C relative to a fixed welding head.

It is understood that when it is mentioned that the piece B is fixed on the piece C, the piece B can be fixed on any element integral with the piece C and for example the piece A.

Alternatively, the attachment of the part A (once it is released by the positioning robot 5) can be interrupted to fix the part B (brought by the positioning robot 5) and freeze the position thereof on the piece C, fixing pieces A and B being completed once the positioning robot has cleared the fixing area.

It goes without saying that the station of the invention is not limited to the assembly of three parts.

Claims

1. Station for fixing at least a first part (A) and a second part (B) on a third part (C), comprising a fixing unit (6, 11), a positioning unit (2, 12) of the third piece, a positioning robot (5) of the first and second pieces on the third piece and a control unit (10) arranged to control: - the positioning robot for positioning the first piece on the third piece,

- the fixing unit to fix the first part on the third part,

the positioning robot for positioning the second piece on the third piece,

- the fixing unit to fix the second part.

Station according to claim 1, wherein the control unit (10) is arranged to control the positioning robot to release the first part when the attachment is sufficiently advanced to freeze the position of the first piece on the third piece. piece, the positioning of the second piece on the third piece occurring while the fixing of the first piece continues.

3. Station according to claim 1, wherein the control unit (10) is arranged to control:

- The positioning robot (5) for releasing the second piece (B) when the attachment is sufficiently advanced to freeze the position of the second piece on the third piece (C), the positioning robot to seek a new first piece during the end of fixing the second piece.

4. Station according to claim 3, wherein the control unit (10) is arranged to control the positioning robot (5) to also fetch a new second piece (B) during attachment of the second piece mounted on the third piece (C).

5. Station according to claim 1, wherein the control unit (10) is arranged to control: - the fixing unit (6) to interrupt the attachment of the first piece (A) to fix the second piece (B ) and fix the position of the latter on the third piece (C),

- the positioning robot (5) to release the second piece and release,

- The fixing unit to complete the fixation of the first part.

6. Station according to claim 1, wherein the positioning robot (5) is equipped with a support (7) having locations (8, 9) for receiving the first piece (A) and the second piece (B). ).

Station according to Claim 6, in which the support (7) has two distinct faces each facing one of the locations (8, 9).

8. Station according to claim 6, wherein the positioning robot (5) is provided with a support changer (7).

9. Station according to claim 1, wherein the fixing unit and a robot (6) equipped with a fixing head.

10. Station according to claim 1, comprising a loader (3, 4) of at least a first and a second part (A, B) on which the positioning robot (5) fetchs the first and second parts.

11. The station of claim 1, wherein the positioning unit (12) of the third piece (C) is controlled to move the third piece, the positioning robot (5) being controlled in a coordinated manner with the unit of positioning.

12. Station according to claim 10, wherein the positioning unit is a robot (12).

13. Station according to claim 10, wherein the fixing unit is a fastening head (12) substantially fixed.