DEVICE FOR AUTOMATED PRODUCTION OF SCREW CONNECTIONS

Abstract

A device is provided for the automated production of screw connections, and includes an articulated robot with an output element and an end link. The output element is arranged on the end link so as to be rotatable around an effector axis (wE). A screwdriver tool is provided, and can be rotated around the effector axis (wE) by the output element. At least one gear may also be provided, where the gear has a direct operative connection to the output element and the screwdriver tool and is set up for transmission of a rotary speed between the output element and the screwdriver tool.

Claims

1. A device for the automated production of screw connections, the device comprising: an articulated robot with a output element and an end link, where the output element is arranged on the end link rotatable around an effector axis (wE); a screwdriver tool rotatable around the effector axis (wE) by the output element; and at least one gear having a direct operative connection to the drive element and the screwdriver tool, the at least one gear transmitting a rotational speed between the drive element and the screwdriver tool.

2. The device in accordance with claim 1, further including a planetary gear, where the output element is connected to a drive link of the planetary gear in a driving manner, wherein a drive link of the planetary gear is connected to the screwdriver tool in a driving manner.

3. The device in accordance with claim 2, wherein the planetary gear comprises a ring gear, a sun gear, and a planetary carrier with planetary gears, where the ring gear is connected to the end link in a torque-proof manner and where the drive link is formed by the planetary carrier and the output link by the sun gear.

4. The device in accordance with claim 1, further including a plurality of planetary gears arranged in series, where a drive link of a first planetary gear is connected in a torque-proof manner to the output element and where an output link of a last planetary gear is connected in a torque-proof manner to the screwdriver tool.

5. The device in accordance with claim 4, wherein the planetary gear comprises a ring gear, a sun gear, and a planetary carrier with planetary gears, where the ring gears are connected to the end link in a torque-proof manner and where the drive link of the first planetary gear is formed by its planetary carrier and the output link of the last planetary gear by its sun gear.

6. The device in accordance with claim 1, wherein the gear features an airtight housing with a suction connection, where the housing is connected to the end link in a torque-proof manner.

7. The device in accordance with claim 6, further including a suction pipe, which is accommodated on the housing in such a way that negative pressure is applied to the housing and the suction pipe via the suction connection, where the screwdriver tool extends axially in the suction pipe, and where the suction pipe features an opening for airtight application of a screw (S).

8. The device in accordance with claim 6, wherein a suction channel extends axially all the way through the screwdriver tool, where the screwdriver tool is accommodated on the gear in such a way that negative pressure can be applied to the housing and the suction channel via the suction connection, such that a screw (S) engages with and is held by the screwdriver tool by the negative pressure.

9. The device in accordance with claim 1, wherein the articulated robot includes six rotary axes, where the effector axis (wE) is formed by the sixth rotary axis and there the end link can be rotated around the fifth rotary axis.

10. The device in accordance with claim 1, further including a torque sensor and/or force sensor interacting with the screwdriver tool.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views.

[0022] FIG. 1 is a schematic cross-section view of a planetary gear.

[0023] FIG. 2 is a partial cross-section view of a first sample embodiment of the inventive device.

[0024] FIG. 3 is a partial cross-section view of a second sample embodiment.

[0025] FIG. 4 is a view of a sample embodiment with 6-axis articulated robot.

DETAILED DESCRIPTION OF THE INVENTION

[0026] FIG. 1 shows a schematic cross-section view of a planetary gear 3 for use in an inventive device along whose effector axis wE the drive link 3a and the output link 3b of the planetary gear 3 are arranged in alignment. The planetary gear 3 comprises the ring gear 31, the sun gear 32 as well as the planetary carrier 33 with the planetary wheels 34. In the present case, only one of the planetary wheels 34 can be seen in the cross-section shown, where for example two further planetary wheels are accommodated on the planetary carrier 33 at a distances of 120° each. Alternatively, a planetary gear with two, four or further planetary wheels can be used. The planetary wheels 34 engage with both the ring gear 31 and the sun gear 32. In an inventive device, the ring gear 31 is held in place, i.e. connected in a torque-proof manner to the end link of the articulated robot, for example via a gearbox. The drive link 3a is formed by the planetary carrier 33 and the output link 3b by the sun gear 32. In an inventive device, the output element of the articulated robot is connected in a driving, i.e. in a torque-proof manner, to the drive link 3a and the output link 3b is connected in a driving manner to the screwdriver tool.

[0027] FIGS. 2 and 3 show schematic partial views of various sample embodiment of the inventive device 100, where of the associated articulated robot only the end link 12 and the output element 11 on the same that can be rotated around the effector axis wE are shown in each case. Screwdriver tool 2, screw S and the suction pipe 6 are each shown in cross-section.

[0028] FIG. 2 shows a first sample embodiment of an inventive device 100 with a planetary gear 3 which has a direct operative connection to the output element 11 and the screwdriver tool 2 and is set up for transmission of a rotary seed between the output element 11 and the screwdriver tool 2. The housing 35 of the planetary gear 3 is connected in a torque-proof manner and rigidly to the end link 12 by means of the retaining device 37. This means that the housing 35 is not included in the rotation of the output element 11. In the drive and output links of the planetary gear 3 hidden inside the housing 35 are connected in a torque-proof manner to the output element 11 or, as the case may be, the screwdriver tool 2.

[0029] The housing 35 is designed to be essentially airtight and so that negative pressure can be applied to it via the suction connection 36. The torque-proof connection of the planetary gear 3 with the output element 11 is designed to be airtight in a manner that is not shown, such as by means of a sealing ring on the housing 35. The suction pipe 6 is accommodated on the housing 35 and negative pressure can be applied to it via the interior of the housing 35 by means of the suction connection 36. The screwdriver tool 2 connected in a torque-proof manner to the output link of the planetary gear 3 extends axially inside the suction pipe 6 along the effector axis wE. The screw S engaged by the screwdriver tool 2 is dimensioned such that the diameter of its head matches the inner diameter of the suction pipe 6 such that the screw makes contact to the wall of the suction pipe 6 in the area of the opening 61 in an essentially airtight manner and due to the negative pressure prevailing in the suction pipe 6 is subject to a pronounced holding effect.

[0030] The torque sensor 71 and the force sensor 72 act to further monitor the screwing process with the device 100; as an example, these are integrated here into the output element 11 of the articulated robot 1.

[0031] FIG. 3 shows a second sample embodiment of an inventive device 100 with a plurality of planetary gears 4 and 5 arranged in series, where the drive link of the first planetary gear 4 is connected in a torque-proof manner to the output element 11 of the articulated robot 1 and where the output link of the last planetary gear 5 is connected in a torque-proof manner to the screwdriver tool 2. In this respect, the two planetary gears 4 and 5 each comprise a ring gear, a sun gear and a planetary carrier with planetary wheels in accordance with FIG. 1, where the ring gears are directly connected in a torque-proof manner to the end link 12 and where the output link of the first planetary gear 4 is formed by its planetary carrier and the output link of the last planetary gear 5 by its sun gear.

[0032] The first planetary gear 4 is accommodated rigidly on the end link 12 of the articulated robot 1 via the housing 45 by means of the retaining device 37 and the housing 45 and 55 of the two planetary gears 4 and 5 are likewise connected in a torque-proof manner to each other such that neither of the housings 45 and 55 are included in a rotation of the output element 11. The series arrangement of the two planetary gears 4 and 5 facilitates a two-stage and thus an especially small transmission ratio of the rotary speed between the output element 11 and the screwdriver tool 2, which makes it possible to realize extremely high rotary speeds at the screwdriver tool 2. It would also be conceivable to use an even larger number of planetary gears arranged in series.

[0033] At least the housing 55 of the last planetary gear 5 is designed to be essentially airtight and can be subjected to negative pressure via the suction connection 56. The screwdriver tool 2 connected in a torque-proof manner to the last planetary gear 5 (not shown here) features the suction channel 20 extending axially along the full length, to which negative pressure can be applied via the interior of the housing 55. This embodiment gives rise to a suction-based holding effect on the screw head drive of screw S that is engaged with the screwdriver tool 2.

[0034] FIG. 4 shows a schematic overview of an inventive device 100 with an articulated robot 1 featuring six rotary axes, where the effector axis wE is formed by the sixth rotary axis w6 and where the end link 12 can be rotated around the fifth rotary axis w5. The planetary gear 3 is accommodated at the end link 12 by means of the retaining device 37 has a direct operative connection with the drive element 11 and the screwdriver tool 2 for transmission of the rotary speed. The inventive 100 exploits the torque at the output element 11 of the articulated robot 1 to perform an efficient process working with a high rotary speed at the screwdriver tool 2 for the automated production of a screw connection with screw S.

[0035] The design of the invention is not limited to the preferred sample embodiment specified above. Rather, a number of variants are conceivable, which make use of the present solution even in designs of a fundamentally different type. All of the features and/or advantages arising from the Claims, the description or the drawings, including design details and physical layouts, may be vital to the invention both by themselves and in a wide variety of combinations.

LIST OF REFERENCE NUMBERS

[0036] 100 Device [0037] 1 Articulated robot [0038] 11 Output element [0039] 12 End link [0040] 2 Screwdriver tool [0041] 20 Suction channel [0042] 3, 4, 5 Planetary gear [0043] 3a Drive link [0044] 3b Output link [0045] 31 Ring gear [0046] 32 Sun gear [0047] 33 Planetary carrier [0048] 34 Planetary wheel [0049] 35, 45, 55 Housing [0050] 36, 56 Suction connection [0051] 37 Retaining device [0052] 6 Suction pipe [0053] 61 Opening [0054] 71 Torque sensor [0055] 72 Force sensor [0056] wE Effector axis [0057] w5 Fifth axis of rotation [0058] w6 Sixth axis of rotation [0059] S Screw