DEVICE FOR TWISTING-OFF AND STRIPPING AN ELECTRODE CAP FROM AN ELECTRODE CAP RECEPTACLE AND STRIPPING DEVICE

Abstract

A device for twisting-off and stripping an electrode cap from an electrode cap receptacle of an end of a welding gun of a welding robot, the device comprising a cap twisting-off unit and further comprising a stripping device. The stripping device is arranged along an insertion path for an electrode cap receptacle with an electrode cap as seen in front of the cap twisting-off unit and along a discharge path for an electrode cap receptacle without or with electrode cap as seen from behind the cap twisting-off unit. The stripping device can be for use in combination with the cap twisting-off unit.

Claims

1. A device for twisting-off and stripping an electrode cap from an electrode cap receptacle of an end of a welding gun of a welding robot, the device comprising: a cap twisting-off unit; and a stripping device arranged along an insertion path for the electrode cap receptacle with the electrode cap as seen from the cap twisting-off unit and along a discharge path for the electrode cap receptacle without or with the electrode cap as seen behind the cap twisting-off unit.

2. The device of claim 1, wherein the cap twisting-off unit is operable to at least partially engage a peripheral region of the electrode cap at least partially inserted into the cap twisting-off unit and, by means of a tensionally force-locking rotation in a first direction of rotation to grip, hold and twist-off in a tensionally force-locking manner the electrode cap at least partially inserted into the cap twisting-off unit, and wherein the stripping device is operable to, when the electrode cap is at least partially inserted into the cap twisting-off unit in order to twist-off the electrode cap, at least partially surround the electrode cap receptacle with at least one obliquely arranged lip, to prevent, while the electrode cap receptacle is moved along the discharge path out of the cap twisting-off unit, the electrode cap from falling back and remaining on the electrode cap receptacle when the electrode cap is dropped by the cap twisting-off unit.

3. The device of claim 2, wherein the stripping device comprises two lips which are equally obliquely arranged, the electrode cap receptacle being movable with the electrode cap along the insertion path between the two lips, and the electrode cap receptacle being movable out without the electrode cap along the discharge path between the two lips.

4. The device of claim 2, wherein the stripping device comprises an enclosure which is arranged around the at least one lip in such a way that the discharge path is formed for the twisted-off and dropped electrode cap.

5. The device of claim 4, wherein the enclosure comprises two side walls, a crossbar, and an end wall.

6. The device of claim 4, wherein the enclosure is in a lower region of the at least one lip and has an opening through which the twisted-off and dropped electrode cap can be removed.

7. The device of claim 2, wherein the at least one lip is a brush or a rubber lip.

8. The device of claim 2, wherein a gradient angle () of the at least one lip is in a range of 20 to 50.

9. A stripping device for use in combination with a cap twisting-off unit, the stripping device comprising: at least one obliquely arranged lip.

10. The stripping device of claim 9, further comprising two lips which are equally obliquely arranged.

11. The stripping device of claim 9, further comprising an enclosure arranged around the at least one lip in such a way that a discharge path is formed for a twisted-off and dropped electrode cap.

12. The stripping device of claim 11, wherein the enclosure comprises two side walls, a crossbar, and an end wall.

13. The stripping device of claim 11, wherein the enclosure has an opening in a lower region of the at least one lip through which the twisted-off and dropped electrode cap can be removed.

14. The stripping device of claim 9, wherein the at least one lip is a brush or a rubber lip.

15. The stripping device of claim 9, wherein a gradient angle () of the at least one lip is in a range of 20 to 50.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] For a more complete understanding of this disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

[0030] FIG. 1 illustrates a schematic oblique view from above of a device for twisting-off and stripping an electrode cap from an electrode cap receptacle of one end of a welding gun of a welding robot;

[0031] FIG. 2 illustrates a front view of a stripping device on the end wall;

[0032] FIG. 3 illustrates a schematic side sectional view of the stripping device of FIG. 2;

[0033] FIG. 4 illustrates a top view of the stripping device; and

[0034] FIGS. 5A-5E illustrate schematic diagrams of an electrode cap removal process from the electrode cap receptacle by means of the stripping device.

DETAILED DESCRIPTION

[0035] FIG. 1 illustrates a schematic oblique view from above of a device 1 for twisting-off and stripping an electrode cap 15 from an electrode cap receptacle of one end of a welding gun of a welding robot. It shows a part of a cap twisting-off unit 2 and a stripping device 3 located below it. The cap twisting-off unit 2 and the stripping device 3 are located at holding structures (not shown) of the device 1.

[0036] The cap twisting-off unit 2 comprises in a spur gear 4 a central opening 5, into which an electrode cap receptacle with an electrode cap 15 can be inserted from below, in a first direction R1 along an insertion path, and the electrode cap receptacle can be removed without the electrode cap downwards, in a second direction R2 along a discharge path. For example, the direction of gravity may also be in the second direction R2.

[0037] On a circle around a central axis 6 of the spur gear 4, three clamping jaws 8 are pivotally mounted on each of the two projecting pins 7 at equal angular distances from each other, whereby the upper three clamping jaws 8 are shown in FIG. 1. The insertion path and the discharge path can run along the axis 6.

[0038] Each clamping jaw 8 is loaded with a tension spring 12 in the direction of an inserted electrode cap. If the spur gear 4 swivels clockwise (arrow R3), the tension springs 12 pull the clamping jaws 8 against an inserted electrode cap 15, which can thus be grasped and held increasingly tighter and then twisted off from the electrode cap receptacle. If the electrode cap receptacle is then moved downwards in the second direction R2 along the discharge path out of the cap twisting-off unit 2, the twisted off electrode cap 15 generally remains in the cap twisting-off unit 2 for the time being, since it is held there.

[0039] After moving the electrode cap receptacle out, the spur gear 4 rotates counterclockwise (arrow R4), when switching over a motor not shown, so that the clamping jaws 8 open and the twisted-off electrode cap 15 can fall out and reach a discharge device. Subsequently, another electrode cap receptacle with an electrode cap 15 can be inserted into the opening 5 of the spur gear 4.

[0040] Since it can happen from time to time that an electrode cap 15 is not held by the cap twisting-off unit 2 after being twisted off and slips back onto the electrode cap receptacle, the stripping device 3 is located below the cap twisting-off unit 2. In the illustration, the stripping device 3 comprises a housing 9 with two side walls 9b, 9c, a crossbar 9d and an end wall 9a. Two lips 10a, 10b are arranged on the side walls 9b, 9c, which lie against each other in an edge area 11.

[0041] The two lips 10a, 10b are each connected to the side walls 9b, 9c, here by screws 13, in a side area opposite the edge area 11.

[0042] The gradient angle (see also FIG. 3) of the two lips 10a, 10b lies in a range of 20 to 50. This gradient angle is determined by the design of the side walls 9b, 9c. Due to the gradient angle, an electrode cap on the surface of the two lips 10a, 10b facing the cap twisting-off unit 2 can slip towards the end wall 9a due to the action of gravity. The direction of gravity can be in the second direction R2, for example.

[0043] If a Cartesian coordinate system is used as a basis, the first direction R1 can run in a positive z direction and the second direction R2 in a negative z direction. The y-axis can be perpendicular to the end wall 9a and the x-axis parallel to the end wall 9a.

[0044] FIG. 2 illustrates a front view of the stripping device 3 on the end wall 9a. The end wall may have a width b1 in a range from 45 mm to 50 mm and a height h in a range from 42 mm to 46 mm.

[0045] FIG. 3 illustrates a schematic lateral sectional view along A-A from FIG. 2. Assuming that the end wall 9a is parallel to the longitudinal axis 6 of the spur gear 4, the gradient angle and the angle between a surface of the two lips 10a, 10b facing the cap twisting-off unit 2 and the end wall 9a can be given as shown. An opening 14 is provided between the two lips 10a, 10b and the end wall 9a through which the dropped and stripped electrode caps can be discharged. Due to the gradient angle a of the two lips 10a, 10b, the dropped and stripped electrode caps are automatically discharged by the force of gravity.

[0046] FIG. 4 illustrates a top view of the stripping device 3. A length 1 can be in a range of 65 mm to 75 mm and a width b2 in a range of 70 mm to 80 mm.

[0047] FIGS. 5A-5E illustrate schematic representations of a stripping process of an electrode cap 15 from the electrode cap receptacle 16 by means of the stripping device 3. The stripping device 3 is shown in the lateral sectional view from FIG. 3.

[0048] In FIG. 5A, an electrode cap receptacle 16 with an electrode cap 15, which was dropped from the electrode cap receptacle 16 by a cap twisting-off unit (not shown) after being twisted off from the electrode cap receptacle 16 and remained on the electrode cap receptacle 16, is moved downwards in the second direction R2 along the discharge path by the stripping device 3. That the electrode cap 15 is no longer fixed on the electrode cap receptacle 16 is indicated by the free area 17 between the electrode cap receptacle 16 and the electrode cap 15.

[0049] In FIG. 5B, the electrode cap receptacle 16 with the electrode cap 15 has been moved in the second direction R2 to such an extent that the electrode cap 15 at least partially comes into contact with the two lips 10a (10b not shown) in a area 18 and thereby the stripping of the electrode cap 15 from the electrode cap receptacle 16 begins.

[0050] In FIG. 5C, the electrode cap receptacle 16 has now been moved even further in the second direction R2, so that the electrode cap 15 has now been completely stripped off the electrode cap receptacle 16 by the two lips 10a (10b not shown). The stripping is finished, and the stripped electrode cap 15 can roll down the slope of the two lips 10a (10b not shown) under the effect of gravity in the direction of the opening 14 provided between the two lips 10a (10b not shown) and the end wall 9a.

[0051] FIG. 5D shows how the stripped cap 15 approaches the opening 14 by rolling down the slope.

[0052] FIG. 5E shows how the stripped cap 15 falls down through the opening 14. The electrode cap 15 can be fed to a waste container, for example.