Abstract
An apparatus for the automated production of screw connections, having an articulated-arm robot and an effector, which is accommodated on an output element of an end member of the articulated-arm robot so as to be rotatable about an effector axis. The effector is in the form of a screwdriving tool, wherein the apparatus has a mouthpiece for providing a screw, the mouthpiece being accommodated on the end member by means of a linear guide and being movable along the effector axis between a feeding position and at least one screwing position.
Claims
1. An apparatus for automated production of screw connections, the apparatus comprising: an articulated-arm robot; an effector that is accommodated on an output element of an end member of the articulated-arm robot so as to be rotatable about an effector axis, the effector being in the form of a screwdriving tool; and a mouthpiece for providing a screw, the mouthpiece being accommodated on the end member via a linear guide and being movable along the effector axis between a feeding position and at least one screwing position.
2. The apparatus according to claim 1, further comprising an electric drive to move the linear guide.
3. The apparatus according to claim 1, further comprising at least one spring that pretensions the mouthpiece into the feeding position.
4. The apparatus according to claim 1, further comprising at least one position sensor to determine a position of the mouthpiece.
5. The apparatus according to claim 1, further comprising a hollow tube adapted to be subjected to negative pressure and is accommodated on the end member via a bearing arm, wherein the screwdriving tool extends axially in the hollow tube, and wherein the hollow tube has a mouth opening for the airtight seating of a screw head.
6. The apparatus according to claim 1, further comprising a screw feeding device via which a screw is fed from a feed hose, which is supplied with compressed air, into the mouthpiece in the feeding position.
7. The apparatus according to claim 1, wherein the articulated-arm robot has six axes of rotation, wherein the effector axis is formed by the sixth axis of rotation, and wherein the end member is rotatable about the fifth axis of rotation.
8. The apparatus according to claim 1, further comprising a torque sensor associated with the screwdriving tool and/or further comprising a force sensor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:
[0020] FIG. 1 shows a cross-sectional view of a first exemplary embodiment of the apparatus of the invention;
[0021] FIG. 2 shows a cross-sectional view of a second exemplary embodiment; and
[0022] FIG. 3 shows a perspective view of the second exemplary embodiment.
DETAILED DESCRIPTION
[0023] FIG. 1 and FIG. 2 show cross-sectional views of advantageous exemplary embodiments of apparatus 100 of the invention, comprising articulated-arm robot 1, of which in each case only end member 12 with output element 11 rotatable thereon is shown, further comprising effector 2, accommodated on output element 11, in the form of screwdriving tool 20, and mouthpiece 3 accommodated on end member 12 by means of linear guide 4. When output element 11 rotates, screwdriving tool 20 rotates about the effector axis wE, which corresponds to the sixth axis of rotation w6 of articulated-arm robot 1, and mouthpiece 3 can be moved along the effector axis wE by means of linear guide 4. For this purpose, linear guide 4 has seat 41, which is rigidly arranged on end member 12, and movable slide 42, on which mouthpiece 3 is accommodated. In the exemplary embodiment of FIG. 1, slide 42 is moved against seat 41 by means of advancing end member 12 with simultaneous contact of mouthpiece 3 with a workpiece, and in the exemplary embodiment of FIG. 2 by actuating electric linear drive 5. The position of slide 42 relative to seat 41, and thus the position of mouthpiece 3, can be determined by means of position sensor 43. Torque sensor 13 and force sensor 14, which are integrated into articulated-arm robot 1 here by way of example, are used for further monitoring of the screwing process with apparatus 100.
[0024] In FIG. 1 and FIG. 2, mouthpiece 3 is in the feeding position in each case, which corresponds to an extreme position of mouthpiece 3 and in which screwdriving tool 20 is not in engagement with the drive at the head of screw S. In the feeding position of mouthpiece 3, a screw S can be fed into mouthpiece 3 by means of feeding device 9, which has a channel opening into mouthpiece 3 from diagonally below the plane of the drawing, typically by means of compressed air via a connected hose. When mouthpiece 3 is moved into a screwing position, i.e., along the effector axis wE in the direction of end member 12, screwdriving tool 20 engages with the screw S and subsequently the screw S is pushed out of mouthpiece 3 at an end and can be screwed into a workpiece provided for this purpose with rotation of output element 11. In the exemplary embodiment of FIG. 1, spring 6 acting on slide 42 is designed as a helical compression spring, in the force-free state of which mouthpiece 3 is in the feeding position. When screwdriving tool 20 is advanced through mouthpiece 3, work must be performed by the articulated-arm robot against spring 6, wherein mouthpiece 3 must be in contact with a workpiece or the like for support.
[0025] In the exemplary embodiment of FIG. 2, seat 41 and slide 42 of linear guide 4 are designed as components of an electric drive 5, and slide 42 can thus be actively moved with mouthpiece 3. Furthermore, screwdriving tool 20 runs in sections in hollow tube 7, which can be subjected to negative pressure and is accommodated on bearing arm 8 and is rigidly arranged via the latter on end member 12 of articulated-arm robot 1. Vacuum connection 71, which can be used to connect a pump, is used to apply the vacuum. In order to make the rearward exit of screwdriving tool 20 from hollow tube 7 as airtight as possible, a sealing ring, for example, is expediently integrated. The front-side mouthpiece opening of hollow tube 7 is designed for the air-tight seating of the screw head of the screw S, so that the screw S is sucked onto hollow tube 7 when mouthpiece 3 is moved to a screwing position, whereby a robust screwing process can be realized. In the embodiment shown here, screwdriving tool 20 is rotatable in hollow tube 7 but not moveable relative thereto. The blade tip of screwdriving tool 20 must therefore be suitably spaced from mouthpiece opening of hollow tube 7 in order to engage positively in the screw head drive of a screw S which is in air-tight contact.
[0026] FIG. 3 shows an overall perspective view of the exemplary embodiment of apparatus 100 of the invention corresponding to FIG. 2. Articulated-arm robot 1 has six axes of rotation, wherein end member 12 is rotatable about the fifth axis of rotation w5. In FIG. 3, mouthpiece 3 is in a screwing position in which hollow tube 7, in the interior of which the screwdriving tool runs concealed and on which the screw S is accommodated, projects far out of mouthpiece 3, so that a screwing process can be initiated by rotating output element 11. Feeding device 9 can be connected via feed hose 91 to a screw conveying device known from the prior art, so that automatic feeding of screws into mouthpiece 3 in the feeding position is possible.
[0027] The invention is not limited in its implementation to the preferred exemplary embodiment described above. Rather, a number of variants are conceivable which make use of the shown solution even in the case of fundamentally different embodiments. All features and/or advantages emerging from the claims, description, or drawings, including structural details and spatial arrangements, can be essential to the invention both alone and in the most diverse combinations.
[0028] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
