DE102010061546A1 - Device for releasing cap from shaft for resistor spot welding plant, has ring segment discs that are mounted in guide such that ring segment discs are moved simultaneously along direction of the longitudinal axis of shaft - Google Patents

Abstract

The device has receiving space (18) for receiving portion of shaft and/or portion of cap. The inner section of ring segment disc (20a) is engaged with gap that is formed between cap and shaft along radial direction. The ring segment discs are supported in guide such that ring segment discs are moved simultaneously along direction of the longitudinal axis of the shaft. An independent claim is included for method for releasing cap from shaft.

Description

FIELD OF THE INVENTION

The invention relates to a tool and a method for releasing a cap seated on a shaft, wherein the cap seated on the shaft forms an annular gap with the shaft. The invention is particularly suitable for detaching electrode caps from an electrode shaft, as used for example in resistance spot welding.

BACKGROUND OF THE INVENTION AND PRIOR ART

In almost all areas of the sheet metal processing industry, in particular in the automotive industry and in body and vehicle construction, the joining of individual sheets and sheet metal components takes place primarily using resistance spot welding methods. The sheet pairings to be welded are pressed together at one point by means of welding tongs, which comprise two opposing electrodes. This is done depending on the manufacturing parameters such as sheet thickness or material, for example under a force of 2 to 3 kN. The pressure is maintained before welding, for example for about 300 ms - the so-called lead time - to ensure that both sheets have full contact. The welding current is now passed through the material from one electrode to another. Depending on the sheet pairing and weld nipple diameter, currents of usually 8 kA to 11.5 kA flow. At the transition between the sheets, the electrical resistance is greatest, so that at this point the melting of the material takes place. The duration of the current flow - the so-called current time - is also 300 ms, for example. Subsequently, in the so-called retention time, which is, for example, 200 ms, the pressure of the welding electrodes is still maintained in order to allow the resulting spot to cool. The current strength of the welding current as well as the holding, current and retention time are typically adjusted to the material parameters.

The working surface of the electrodes is the electrode cap at the tip of the electrode shaft. Electrode caps are usually clean milled bodies. Due to the high welding currents combined with high contact pressures, however, the electrode caps are subject to heavy wear during operation. Her clean milled work surface deforms and becomes crowned with increasing number of set welding points. In addition, an oxide layer is formed on the cap surface which affects the resistance of the electrode.

In order to remove the oxide layer and restore the basic shape of the electrode cap, in large-scale industrial applications, a robot drives the electrode to a cap milling station at regular intervals, for example after setting 600 welds each. There, the caps are milled back into their original basic shape using carbide indexable inserts.

If the electrode caps are very worn, for example, after a total of 6000 welds, but a cap change is inevitable. Changing the caps is currently usually done by hand with the help of pliers or Abdrehhilfen, z. B. using pipe wrenches. However, jerky detachment of the electrode caps from the electrode shaft leads to undesired forces and to high bending and torsional moments. Such forces are transmitted to the bearing of the sleeves and can cause an undesirable point offset during subsequent welding on the workpiece.

Instead of hand tools and automatic changing devices for electrode caps have been proposed, which can be integrated into an automatic resistance spot welding system or production line.

For example, the DE 36 05 099 A1 a device for replacing the electrode caps of a robot spot welding gun with two eccentric ring spanners. The annular disc of one of the eccentric ring spanner encompasses the cap-changing cylindrical electrode shaft, the annular disc of the other eccentric ring key the. likewise cylindrical electrode cap. The annular discs lie on each other and each have on the sides facing each other small cams. When turning the ring key against each other, the cams slide on each other, whereby the electrode cap is moved relative to the electrode shaft along the longitudinal axis of the electrode shaft and thereby withdrawn from the electrode shaft.

A disadvantage of this eccentric configuration is, on the one hand, that the annular disks only come into contact with the cylinder jacket of the electrode cap or of the electrode shaft along a partial region of its inner circumference so that the force can not be applied along the entire circumferential line of the electrode cap and, in turn, torsional moments occur. In addition, the clamping of the electrode cap in the annular disc of the eccentric key causes the electrode cap is pressed in the radial direction against the shaft on which it sits. But that makes it difficult the removal of the electrode cap from the electrode shaft.

The DE 35 15 597 A1 describes an alternative method of self-replacing electrode caps on welding electrode shafts, in which the electrode shank is clamped in an annular disk and the electrode cap is clamped using a sickle disk. Ring disc and sickle disc are rotated against each other and simultaneously removed from each other along the axial direction of the electrode shaft. Due to the superimposed turning and pulling movement, the electrode cap is pulled off the electrode shaft.

Another changing device for electrode caps is in the utility model DE 299 14 968 U1 described. Wedge elements are inserted laterally, ie perpendicular to the axial direction of the electrode shaft, into the gap between the electrode shaft and the electrode cap, thereby pushing the electrode caps off the electrode shaft in the axial direction. This configuration has the advantage over the aforementioned solutions that the forces act evenly on both sides of the electrode cap and the electrode cap is not pressed against the jacket of the electrode shaft. However, the insertion of the wedge elements in the gap necessarily leads to an undesirable transverse force on the electrode tongs and thus to a fatigue of the sleeve material and a possible point offset of the welds.

There is therefore a need for an improved electrode cap releasing device which permits rapid detachment of electrode caps from the electrode shaft while avoiding undesirable transverse or torsional forces on the electrode shaft.

OVERVIEW OF THE PRESENT INVENTION

This object is achieved by the device according to the invention with the features of claim 1 and the inventive method with the features of claim 9. The dependent claims relate to preferred embodiments.

A device for releasing a cap from a shaft according to the present invention comprises a guide and at least two ring segment discs which oppose each other in the guide and together form a receiving space for receiving at least a portion of the shaft and / or a portion of the cap. The ring segment discs are rotatably mounted in the guide along a circumferential direction of the ring segment discs about a longitudinal axis of the shaft and slidably mounted for engagement with at least one inner portion of the ring segment discs in the gap between the cap and shaft along a direction which at least one component in the radial direction with respect Has longitudinal axis. The ring segment discs are further supported in the guide such that when rotated about the shaft, the ring segment discs move simultaneously in the direction of the longitudinal axis of the shaft, at least in a configuration in which the ring segment discs engage at least one inner section into the gap between the cap and shaft ,

The device according to the invention allows the quick and easy release of a cap from a shaft, with which the cap forms an annular gap, with disturbing Torsionsmomente and lateral forces are largely avoided on the electrode shaft.

The displaceability of the ring segment discs in the guide in a direction radial with respect to the longitudinal axis allows insertion of an inner portion of the ring segment discs into the gap between the shaft and cap. By subsequently moving the ring segment discs in the direction of the longitudinal axis of the shaft, the cap can be stripped off the shaft. Since the stripping is done primarily by using axial forces, the shaft is exposed to no or only negligible lateral forces and torsional forces. In addition, the formation of the ring segment discs allows engagement along the entire or almost entire annular gap between the shaft and cap and thus an advantageous force distribution and a uniform detachment of the cap from the shaft.

In a preferred embodiment, an underside of the ring segment discs and / or a bearing portion of the guide, on which rest the ring segment discs, at least along a portion of its circumferential direction is formed as an inclined plane. This allows at least partial implementation of a rotational movement of the ring segment discs relative to the guide in an axial movement when the ring segment discs engage at least partially in the gap between the cap and shaft. A rotational movement along the inclined plane then leads to a force spreading the gap and thus to a detachment of the cap from the shaft.

Preferably, the guide comprises an annular or circular disc having at least two pin elements on its underside, wherein the ring segment discs each have at least one slot-shaped recess for receiving one of the pin elements on its upper side and the Recess in one direction is oriented obliquely to the circumferential direction of the ring segment discs and obliquely to the radial direction of the ring segment discs. A rotational movement of the annular or circular disc can be transmitted in this way via the pin elements which engage in the slot-shaped recesses of the ring segment discs, in a rotational movement of the ring segment discs and a simultaneous movement of the ring segment discs radially inwardly. By choosing the orientation or direction of the recess, the ratio of radial movement to transverse movement can be suitably adjusted, for example, to adapt to the diameter of the shaft or the cap.

In a preferred embodiment, the device comprises four ring segment discs, wherein a first ring segment disc and a second ring segment disc oppose each other in the guide and a third ring segment disc and a fourth ring segment disc oppose each other in the track, the first and second ring segment discs having a first port for receiving at least one Form part of the shaft and / or a portion of the cap, the third ring segment disc and the fourth ring segment disc form a second opening for receiving a portion of the shaft and / or a portion of the cap, the first ring segment disc rests on the third ring segment disc and the second ring segment disc the fourth ring segment disc rests. The first and second openings may be concentric openings, in particular substantially circular openings, and together form the receiving space for receiving the shank portion and / or the cap portion.

In a further development, the ring segment discs are mounted in the guide such that the first ring segment disc cooperates with the third ring segment disc when rotating about the shaft to spread the gap and / or the second ring segment disc cooperates with the fourth ring segment disc when rotating about the shaft to spread the gap.

The first, second, third and fourth ring segment discs according to the foregoing embodiment may be rotatably supported in the guide along its circumferential direction about a longitudinal axis of the shaft and slidably supported for engaging at least one inner portion of the ring segment discs in the gap between the cap and shaft to the longitudinal axis , In this case, the ring segment discs can be mounted in the guide in such a way that the first ring segment disc moves simultaneously with the third ring segment disc when rotating about the shaft in the direction of the longitudinal axis of the shaft and the second ring segment disc relative to the fourth ring segment disc when rotating about the shaft simultaneously in the direction the longitudinal axis of the shaft moves.

By synchronous movement of the first ring segment disc relative to the third ring segment disc and the second ring segment disc relative to the fourth ring segment disc along the longitudinal axis of the shaft, the cap acts on both sides of a uniform force along the longitudinal direction of the shaft.

Preferably, the thickness of the first, second, third and fourth ring segment discs varies along at least a portion of the respective circumferential direction of the respective ring segment disc, the greater thickness end of the first ring segment disc being in the same direction as the smaller third end segment disc and end or wherein the greater thickness end of the second ring segment disc faces in the same direction as the smaller thickness end of the fourth ring segment disc. Particularly preferably, the corresponding thickness varies continuously along at least a portion of the circumferential direction, preferably along the entire circumferential direction.

The configuration of the aforementioned embodiment with two pairs of superimposed ring segment discs whose facing sides are inclined in opposite directions, allows a quick spreading of the gap between the cap and shaft with only slight rotation of the ring segments against each other and therefore further reduces the torsional moment acting on the shaft.

In a development of the abovementioned embodiments, the guide comprises a first annular or circular disk which has at least two first pin elements on its underside, and the first and second ring segment disks each comprise at least one slot-shaped recess for receiving one of the first pin elements at its upper side Recess in a first direction is oriented obliquely to the circumferential direction of the first and second ring segment discs and obliquely to the radial direction of the first and second ring segment discs. Furthermore, the guide comprises a second annular or circular disc which has at least two second pin elements on its upper side, wherein the third and fourth ring segment disc each have at least one slit-shaped recess for receiving one of the second pin elements on its underside and the recess is inclined in a second direction to the circumferential direction of the third and fourth ring segment discs and obliquely to the radial direction the third and fourth ring segment discs is oriented. The second direction may in particular be oriented mirror-inverted to the first direction or form a right angle with the first direction.

The aforementioned embodiment is particularly suitable for capping. Upon rotation of the first disc and the second disc, the pin members move in their associated recess, and the first and third ring segment disc move synchronously, while maintaining their relative position along a circumferential direction of the shaft and at the same time radially inwardly due to the static friction forces acting therebetween. When the inclined planes of the ring segment discs face each other but are oppositely oriented, as described with reference to the aforementioned embodiment, the total thickness of the first and third ring segment discs remains constant during the common rotational movement. In this way, a common inward movement of the inner portion of the first and third ring segment disc in the gap between the cap and shaft until the first pin elements have reached the end of the slot-shaped recess and the inner sides of the first and third ring segment discs engage in the gap between the cap and shaft and abut the shaft. Starting from this configuration, upon further rotation of the annular or circular disc, a rotational movement of the first ring segment disc relative to the third ring segment disc now takes place. In this case, slides the underside of the first ring segment disc with its inclined plane on the inclined plane of the top of the third ring segment disc, so that the total thickness of the first and third ring segment disc increases and spreads the gap between the shaft and cap, whereby the cap is released from the shaft.

Correspondingly, the second and fourth ring segment discs initially move synchronously into the gap between the shaft and the cap and spread the gap between the cap and shaft during further rotation of the second annular or circular disc with mutual displacement.

The device according to the present invention can be used both in an automatically operated changing device for electrode caps as well as in a manually operated hand tool. For use in a hand tool, the device is particularly suitable because the invention allows due to the use of ring segment discs, which move into the gap between the cap and shaft and spread the gap, a particularly compact design and a detachment of the cap with only a slight rotational movement. Furthermore, since the ring segment discs engage in the gap between the cap and shaft, it is not necessary to lock the shaft when capping. A fitting of the cap changer and a centering on the gap is sufficient. By subsequent rotational movement of the ring segment discs against each other, as they can be performed comfortably and quickly with two hands, then the cap can be easily and easily deported from the shaft. The hand tool can for this purpose in particular comprise two grip elements, wherein a first grip element engages directly or indirectly on two ring segment discs and a second grip element engages directly or indirectly on the receptacle and / or on two further ring segment discs.

The ring segment discs preferably have a constant radial diameter perpendicular to the circumferential direction. However, the radial diameter of the ring segment discs may also vary along a circumferential direction of the ring segment discs, wherein the ring segment discs may be formed as sickles.

Preferably, the ring segment discs span an angular range of 30 ° to 180 °, more preferably 90 ° to 150 °.

The invention also relates to a method for detaching a cap from a shaft, wherein the cap seated on the shaft forms an annular gap with the shaft, with the steps of inserting at least a portion of the shaft and / or a portion of the cap into one of receiving space formed by two opposing ring segment discs, inserting at least a portion of the ring segment discs into the gap between the shaft and cap by moving the ring segment discs in a direction having at least one component in the radial direction with respect to the longitudinal axis of the shaft, and sliding the cap off the shaft by moving the ring segment discs in the direction of the longitudinal axis of the shaft.

As a result of the method according to the invention, the advantages described above with reference to the device according to the invention are obtained in comparison with the prior art.

In a preferred embodiment, the insertion of the ring segment discs in the gap and / or the movement of the ring segment discs in the direction of the longitudinal axis of the shaft with simultaneous rotation of the ring segment discs along a circumferential direction of the shaft.

Preferably, the inventive method comprises inserting at least a portion of the shaft and / or at least a portion of the cap into a receiving space formed by four ring segment discs, wherein a first ring segment disc and a second ring segment disc face each other and form a first opening with each other and with a third ring segment disc and a fourth ring segment disc forming a second opening with each other, wherein the first ring segment disc rests on the third ring segment disc and the second ring segment disc rests on the fourth ring segment disc and the receiving space comprises the first opening and the second opening, and further inserting into the gap the common insertion of at least a portion of the first ring segment disc and at least a portion of the third ring segment disc into the gap and the common insertion of at least a portion of the second ring segment disc and comprises at least a portion of the fourth ring segment disc in the gap.

Preferably, the removal of the cap comprises spreading the gap.

In a further development of the aforementioned embodiments, the first ring segment disc and the third ring segment disc maintain their relative position relative to one another during insertion into the gap and / or retain the second ring segment disc and the fourth ring segment disc relative to one another during insertion into the gap.

Preferably, in the aforementioned embodiments, the sliding of the cap comprises rotational movement of the first ring segment disc relative to the third ring segment disc and / or rotational movement of the second ring segment disc relative to the fourth ring segment disc.

In a further development, the removal of the cap at the same time as the rotational movement of the first ring segment disc relative to the third ring segment disc axial movement of the first ring segment disc relative to the third ring segment disc along the longitudinal axis of the shaft and / or includes the deporting of the cap simultaneously to the rotational movement of the second ring segment disc relative to the fourth ring segment disc an axial movement of the second ring segment disc relative to the fourth ring segment disc along the longitudinal axis of the shaft.

In a preferred embodiment, the ring segment discs are guided during insertion into the gap via engaging in slot-shaped recesses on the top and / or bottom of the ring segment discs pin elements.

In the above-mentioned embodiments, the shaft may in particular be the electrode shaft of a welding tongs, and the cap may in particular be the electrode cap of a welding tongs placed on the electrode shaft.

The invention also relates to a resistance welding method comprising (a) repeatedly performing steps 1 to 3, wherein step 1 comprises feeding a pair of materials to a resistance welding apparatus having at least one welding gun with at least two opposing electrodes, step 2 compressing material and electrodes at one point, and step 3 comprises applying a welding current flowing through both electrodes and the material, and (b) after repeatedly performing steps 1 to 3, changing the electrode caps, detaching an electrode cap from an electrode shaft according to the method one of the aforementioned embodiments.

The invention enables the rapid detachment of the electrode cap from the electrode shaft and avoids unwanted transverse and torsional forces on the electrode shaft almost completely. As a result, on the one hand a premature fatigue of the quill material of the electrode shaft is prevented. At the same time an undesired shifting or twisting of the electrode shafts and an associated point offset of the welding points is avoided, thereby increasing the precision of the welding process as a whole.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The features and numerous advantages of the inventive device and method of capping can best be understood by reference to a detailed description of the accompanying drawings, in which:

1 shows a perspective view of an electrode shaft with cap;

2a shows a perspective view of a cap release tool according to the invention in the open position;

2 B shows a sectional view of the cap release tool according to the invention in the open state;

3a the ring element discs of the cap release tool in its normal position shows;

3b shows the ring element discs of Kappenlösewerkzeugs in mutually rotated position;

4 shows a handle of the cap release tool with cylinder pins in a perspective view;

5a shows a perspective view of the cap release tool in the delivered state;

5b a sectional view of the cap release tool in the delivered state of 5a shows;

6a shows a perspective view of the cap release tool in overfed state; and

6b the cap change tool in the over-springed state of 6a in a sectional view shows.

1 shows an electrode shaft 10 with attached electrode cap 12 as used in welding tongs for resistance spot welding systems. The electrode tape 12 forms with the electrode shaft 10 an annular cap gap 14 , Through the electrode cap 12 During the welding operation, electric currents of usually 8 kA to 11.5 kA flow. At the same time, the electrode caps are pressed under high pressure onto the workpiece to be welded. Due to the resulting wear, it is necessary, the electrode cap 12 to change at regular intervals.

For releasing or pushing off the electrode cap 12 from the electrode shaft 10 serves the hand tool according to the invention, which in 2a schematically in a perspective view and in 2 B is shown in a sectional view.

The electrode cap release tool comprises a guide designed as an annular shell 16 with a central opening 18 into the electrode shaft 10 and the electrode cap 12 be at least partially included. In the lead 16 are a first pair of ring segment discs having a first ring segment disc 20a and a second ring segment disc 20b and a second pair of ring segment discs with a third ring segment disc 22a and a fourth ring segment disc 22b about a longitudinal axis Z of the tool (which in use with the axis of the introduced into the tool electrode shaft 10 coincident) rotatably and radially with respect to the longitudinal axis Z slidably mounted.

The configuration of the ring segment discs and their relative arrangement is shown in the figure 3a shown in more detail. The first ring segment disc 20a lies with its underside on the top of the third ring segment disc 22a on. The underside of the first ring segment disc 20a and the top of the third ring segment disc 22a are each formed along their circumferential direction as an inclined plane. As from the representation of 3a can be seen, takes the thickness of the first ring segment disc 20a along the circumferential direction in a clockwise direction continuously increasing, the thickness of the third ring segment disc 22a continuously off. The end 24 with the smaller thickness of the first ring segment disc 20a is the end 26 with the larger thickness of the third ring segment disc 22a adjacent. Accordingly, on the opposite side of the ring segment discs is the end 28 with the larger thickness of the first ring segment disc 20a the end 30 with the smaller thickness of the third ring segment disc 22a adjacent. The gradients of the inclined plane of the underside of the first ring segment disc 20a and the inclined plane of the top of the third ring segment disc 22a are equal in magnitude, but opposite, so that the total thickness of the first ring segment disc 20a and third ring segment disc 22a is constant over the entire circumference of the ring segment discs.

The first ring segment disc 20a is in the lead 16 the second ring segment disc 20b across from. The third ring segment disc 22a is corresponding to the fourth ring segment disc 22b across from. The second ring segment disc 20b lies with its underside on the top of the fourth ring segment disc 22b on. The structure of the second ring segment disc 20b and the fourth ring segment disc 22b corresponds to that of the first ring segment disc 20a or third ring segment disc 22a , In particular, the underside of the second ring segment disc are also 20b and the top of the fourth ring segment disc 22b each formed as an inclined plane, wherein the end of the smaller thickness of the second ring segment disc 20b again the end with the larger thickness of the fourth ring segment disc 22b facing and vice versa. The gradients of the inclined plane of the second ring segment disc 20b and the fourth ring segment disc 22b In turn, they are the same in amount, but in opposite directions. Also the total thickness of second ring segment disc 20b and fourth ring segment disc 22b therefore remains constant along the circumference of the ring segment discs.

The opening between the first ring segment disc 20a and the second ring segment disc opposite it 20b and the opening between the third ring segment disc 22a and the fourth ring segment disc opposite it 22b taken together form a section of the recording room 18 for receiving the electrode shaft 10 or the electrode cap 12 ,

That the recording room 18 facing inner profile of the second ring segment disc 20b and fourth ring segment disc 22b Completely corresponds to the recording room 18 facing inner profile of the first ring segment disc 20a and third ring segment disc 22a and is by rotation about 180 ° about the longitudinal axis Z out of it.

In the lead 16 become the first ring segment disc 20a and the second ring segment disc 20b upwards through a first annular disc 32 completed, which with a first handle element 34 is operatively linked and in the leadership 16 is mounted rotatably about the Längsache Z. The lower inside of the guide 16 on which the third ring segment disc 22a and the fourth ring segment disc 22b rest, is accordingly as a second annular disc 36 formed and with a second handle element 38 operatively connected.

As in the presentation of 4 is shown, with the first handle element 34 connected first annular disc 32 on its underside two diametrically opposed cylindrical pin element 40a . 40b on. Accordingly, the second annular disc 36 the leadership 16 on its upper side two diametrically opposed cylindrical pin elements (not shown in the figures). The pin elements of the first annular disc 32 or the second annular disc 36 serve the power transmission of the first handle element 34 or second handle element 38 on the upper pair of ring segment discs 20a . 20b or on the lower pair of ring segment discs 22a . 22b , For this purpose, the first ring segment disc 20a on its upper side a slot-shaped recess 44a into which the pin element 40a engages from above. The recess 44a is oblique to the circumferential direction of the ring segment disc 20a and obliquely to the radial direction of the ring segment disc 20a oriented. In the embodiment shown, the longitudinal axis of the recess forms 44a both with the radial direction and with the circumferential direction of the ring segment disc 20a each at an angle of about 45 °. By suitable choice of the angle, the ratio of rotational movement about the longitudinal axis Z and inward movement or outward movement in the radial direction can be predetermined and, for example, to the diameter of the electrode shaft 10 or electrode cap 12 to adjust.

The third ring segment disc 22a has on its underside a corresponding slot-shaped recess 45a for receiving a pin element 42a the second annular disc 36 on (not shown in the figures).

Accordingly, the second ring segment disc 20b on its upper side a slot-shaped recess 44b for receiving the pin element 40b the first annular disc 32 on. The slot-shaped recess 44b is again to both the radial direction and the circumferential direction of the second ring segment disc 20b inclined, wherein the inclination of the slit-shaped recess 44a the first ring segment disc 20a corresponds, but is opposite, as in 3a shown. A corresponding slot-shaped recess 45b for receiving a pin element 42b the second annular disc 36 is at the bottom of the fourth ring segment disc 22b trained (in 3a Not shown).

As seen from the sectional view of 2 B it can be seen, is the first annular disc 32 upwards via resilient pressure pieces 46 on a fixed or detachable with the guide 16 connected cover ring disc 48 stored. In the basic position are the pressure pieces 46 slightly biased. They allow a displacement of the first ring segment disc 20a and the second ring segment disc 20b as well as the first annular disc 32 against the restoring force of the pressure pieces 46 along the longitudinal axis Z.

For loosening an electrode cap 12 from an electrode shaft 10 The cap release tool is initially over the electrode cap 12 slipped up until the receiving space 18 facing inner sides of the ring segment discs 20a . 20b . 22a . 22b at the height of the cap gap 14 are located. This configuration is in the sectional view of 2 B clearly visible.

Starting from the in 2a and 2 B shown opened state in the handle elements 34 . 38 toward each other. The cylindrical pin elements 40a . 40b . 42a and 42b move in the slot-shaped recesses 44a . 44b . 45a and 45b the ring segment discs 20a . 20b . 22a and 22b so that the ring segment discs 20a . 20b . 22a and 22b migrate radially inwardly perpendicular to the longitudinal axis Z and finally with her the receiving space 18 facing inner portion in the cap gap 14 intervention. The slot-shaped recesses 44a . 44b . 45a and 45b are doing so on the diameter of the electrode shaft 10 or the electrode cap 12 matched that the cylindrical pin elements 40a . 40b . 42a and 42b the respective end of the slot-shaped recess 44a . 44b . 45a and 45b reach when the inner sections of the ring segment discs 20a . 20b . 22a and 22b within the cap gap 14 abut against the lateral surface of the electrode shaft 10 or almost abut, but at least the lower edge portion of the electrode cap 12 engage behind.

Due to the stiction between the first ring segment disc 20a and the underlying third ring segment disc 22a keep the first and third ring segment disc during delivery their relative position to each other and move together in the cap gap 14 into it. A rotation of the first ring segment disc 20a opposite the third ring segment disc 22a does not initially take place, so that the total thickness of the first and third ring segment disc is maintained during the feed movement. Accordingly, keep the second ring segment disc 20b and the underlying fourth ring segment disc 22b their relative position during insertion into the cap gap 14 initially at.

In 5a and 5b the cap release tool is shown in maximum radial delivery. The first ring segment disc 20a , the second ring segment disc 20b , the third ring segment disc 22a and the fourth ring segment disc 22b lie with their inner sections in the cap gap 14 on the lateral surface of the electrode shaft 10 on and engage behind the lower edge portion of the electrode cap 12 ,

Starting from this position where the final radial feed is achieved and the cylindrical pin elements 40a . 40b . 42a and 42b at the respective end of the slot-shaped recesses 44a . 44b . 45a and 45b the ring segment discs 20a . 20b . 22a and 22b have arrived, takes place on further rotation of the handle elements 34 . 38 against each other a rotation of the first ring segment disc 20a opposite the underlying third ring segment disc 22a and a rotation of the second ring segment disc 20b opposite the underlying fourth ring segment disc 22b , The first ring segment disc 20a slides the inclined plane of the underlying third ring segment disc 22a up, as in the picture of 3b illustrated. Accordingly, the second ring segment disc slides 20b the inclined plane of the underlying fourth ring segment disc 22b up. In this case, the total thickness of the stratification of the first ring segment disc increases 20a and third ring segment disc 22a in the axial direction Z. Accordingly, the total thickness of the layering of the second ring segment disc increases 20b and fourth ring segment disc 22b along the axial direction Z. The first ring segment disc 20a and the second ring segment disc 20b therefore move against the restoring force of the resilient plungers 46 upwards until the inner edge of its top at the bottom of the edge of the electrode cap 12 is applied. This configuration is in the illustration of 6a and 6b shown.

Upon further rotation of the first handle element 34 against the second handle element 38 is over the top of the first ring segment disc 20a and the opposite second ring segment disc 20b an axial force in the direction of the longitudinal axis Z on the lower edge of. electrode cap 12 exercised, so that the electrode cap 12 in the axial direction of the electrode shaft 10 solves. Starting from the in 6a and 6b shown position is only a small relative rotation of the handle elements, for example, less than 5 °, necessary so that the electrode cap 12 essentially exclusively axial forces act and torsional forces and shear forces on the electrode shaft 10 be avoided as far as possible. The tool according to the invention in this way enables a fast and thereby low-wear detachment of the electrode cap 12 from the electrode shaft 10 ,

The cover ring disc 48 can be in the embodiment shown by the leadership 16 Loosen so that the ring segment discs 20a . 20b . 22a and 22b Simply replace to fit different diameter of the electrode shaft 10 or the electrode cap 12 adapt. In practice, three different cap diameters (13 mm, 16 mm and 20 mm) are used so that correspondingly three sets of ring segment discs can be provided.

The invention has been illustrated above using the example of detaching electrode caps from an electrode shaft. However, as the person skilled in the art immediately recognizes, the device according to the invention or the method according to the invention is not limited to this application, but can advantageously be used wherever a cap is to be detached from a shaft and shaft and cap form an annular gap into which the ring segment discs can intervene.

The description of the preferred embodiment and the figures serve only to illustrate the device according to the invention and the method according to the invention and the technical effects achieved therewith but are not intended to limit the invention. The scope of the invention arises solely from the following claims.

LIST OF REFERENCE NUMBERS

10

electrode shaft

12

electrode cap

14

cap gap

16

guide

18

opening

20a

first ring segment disc

20b

second ring segment disc

22a

third ring segment disc

22b

fourth ring segment disc

24

End with smaller thickness of the first ring segment disc 20a

26

End with greater thickness of the third ring segment disc 22a

28

End with greater thickness of the first ring segment disc 20a

30

End with smaller thickness of the third ring segment disc 22a

32

first annular disc

34

first handle element

36

second annular disc

38

second handle element

40a, 40b

Pin elements of the first annular disc 32

42a, 42b

Pin elements of the second annular disc 36

44a

slit-shaped recess of the first ring segment disc 20a

44b

slit-shaped recess of the second ring segment disc 20b

45a

slit-shaped recess of the third ring segment disc 22a

45b

slit-shaped recess of the fourth ring segment disc 22b

46

resilient plungers

48

Deck washer

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 3605099 A1 [0007]
• DE 3515597 A1 [0009]
• DE 29914968 U1 [0010]

Claims (18)

Device for releasing a cap ( 12 ) of a shaft ( 10 ), whereby the on the shaft ( 10 ) seated cap ( 12 ) with the shaft ( 10 ) an annular gap ( 14 ), with: a guided tour ( 16 ); and at least two ring segment discs ( 20a . 20b ), who are in each other's leadership ( 16 ) and with each other a receiving space ( 18 ) for receiving at least a portion of the shaft ( 10 ) and / or a portion of the cap ( 12 ) form; wherein the ring segment discs ( 20a . 20b ) in the leadership ( 16 ) along its circumferential direction about a longitudinal axis (Z) of the shaft ( 10 ) are rotatably mounted and for engaging with at least one inner portion of the ring segment discs ( 20a . 20b ) in the gap ( 14 ) between cap ( 12 ) and shank ( 10 ) are slidably mounted along a direction having at least one component in the radial direction with respect to the longitudinal axis (Z); and wherein the ring segment discs ( 20a . 20b ) so in the leadership ( 16 ) are mounted, that the ring segment discs ( 20a . 20b ) when turning around the sheep ( 10 ) simultaneously in the direction of the longitudinal axis (Z) of the shaft ( 10 ) move. Device according to Claim 1, in which a lower side of the ring segment discs ( 20a . 20b ) and / or a bearing section of the guide ( 16 ) on which the ring segment discs ( 20a . 20b ), at least along a portion of its circumferential direction is formed as an inclined plane. Device according to one of the preceding claims, in which the guide ( 16 ) comprises an annular or circular disc ( 32 ), which at least two pin elements ( 40a . 40b ), and in which the ring segment discs ( 20a . 20b ) at its top in each case at least one slot-shaped recess ( 44a . 44b ) for receiving one of the pin elements ( 40a . 40b ), wherein the recess ( 44a . 44b ) in a direction oblique to the circumferential direction of the ring segment discs ( 20a . 20b ) and obliquely to the radial direction of the ring segment discs ( 20a . 20b ) is oriented. Device according to one of the preceding claims with four ring segment discs ( 20a . 20b . 22a . 22b ), wherein a first ring segment disc ( 20a ) and a second ring segment disc ( 20b ) each other in the leadership ( 16 ) and a third ring segment disc ( 22a ) and a fourth ring segment disc ( 22b ) each other in the leadership ( 16 ) and concentric openings for receiving at least a portion of the shaft ( 10 ) and / or a portion of the cap ( 12 ), wherein the first ring segment disc ( 20a ) on the third ring segment disc ( 22a ) rests and the second ring segment disc ( 20b ) on the fourth ring segment disc ( 22b ) rests. Apparatus according to claim 4, wherein the ring segment discs ( 20a . 20b . 22a . 22b ) are mounted in the guide such that the first ring segment disc ( 20a ) with the third ring segment disc ( 22a ) when turning around the shaft ( 10 ) interacts with the gap ( 14 ), and / or the second ring segment disc ( 20b ) with the fourth ring segment disc ( 22b ) when turning around the shaft ( 10 ) interacts with the gap ( 14 ) spread open. Apparatus according to claim 4 or 5, wherein the thickness of the first ( 20a ), second ( 20b ), third ( 22a ) and fourth ( 22b Ring segment disc varies along at least a portion of their respective circumferential direction, in particular varies continuously, wherein the end ( 28 ) with the greater thickness of the first ring segment disc ( 20a ) in the same direction as the end ( 30 ) with the smaller thickness of the third ring segment disc ( 22a ) and / or wherein the end with the greater thickness of the second ring segment disc ( 20b ) in the same direction as the end with the smaller thickness of the fourth ring segment disc ( 22b ). Device according to one of claims 4 to 6, wherein the guide ( 16 ) a first annular or circular disc ( 32 ), which on its underside at least two first pin elements ( 40a . 40b ), and in which the first ( 20a ) and second ( 20b ) Ring segment disc on its upper side in each case at least one slot-shaped recess ( 44a . 44b ) for receiving one of the first pin elements ( 40a . 40b ), wherein the recess ( 44a . 44b ) in a first direction oblique to the circumferential direction of the first ( 20a ) and second ( 20b ) Ring segment discs and oblique to the radial direction of the first ( 20a ) and second ( 20b ) Ring segment discs is oriented, and in which the leadership ( 16 ) a second annular or circular disc ( 36 ), which on its upper side at least two second pin elements ( 42a . 42b ), and in which the third ( 22a ) and fourth ( 22b ) Ring segment disc on its underside at least one slot-shaped recess ( 45a . 45b ) for receiving one of the second pin elements ( 42a . 42b ), wherein the recess ( 45a . 45b ) in a second direction oblique to the circumferential direction of the third ( 22a ) and fourth ( 22b Ring segment discs and obliquely to the radial direction of the third ( 22a ) and fourth ( 22b ) Ring segment discs is oriented. Device according to one of the preceding claims, wherein the device comprises a hand tool with at least two handle elements ( 34 . 38 ), wherein a first grip element ( 34 ) directly or indirectly on two ring segment discs ( 20a . 20b ) and a second handle element ( 38 ) directly or indirectly to the leadership ( 16 ) and / or on two further ring segment discs ( 22a . 22b ) attacks. Method for releasing a cap ( 12 ) of a shaft ( 10 ), whereby the on the shaft ( 10 ) seated cap ( 12 ) with the shaft ( 10 ) an annular gap ( 14 ), comprising the steps of: introducing at least a portion of the stem ( 10 ) and / or a portion of the cap ( 12 ) in one of two opposing ring segment discs ( 20a . 20b ) trained receiving space ( 18 ); Inserting at least a portion of the ring segment discs ( 20a . 20b ) in the gap ( 14 ) between shaft ( 10 ) and cap ( 12 ) by moving the ring segment discs ( 20a . 20b ) in a direction that at least one component in the radial direction with respect to the longitudinal axis (Z) of the shaft ( 10 ) having; and pushing off the cap ( 12 ) of the shaft ( 10 ) by moving the ring segment discs ( 20a . 20b ) in the direction of the longitudinal axis (Z) of the shaft ( 10 ). Method according to claim 9, in which the insertion of the ring segment discs ( 20a . 20b ) in the gap ( 14 ) and / or moving the ring segment discs ( 20a . 20b ) in the direction of the longitudinal axis (Z) of the shaft ( 10 ) while simultaneously rotating the ring segment discs ( 20a . 20b ) along a circumferential direction of the shaft ( 10 ) he follows. Method according to one of claims 9 to 11, in which the removal of the cap ( 12 ) the spreading of the gap ( 14 ). Method according to one of claims 9 to 11, wherein the insertion into the receiving space ( 18 ) the insertion of at least a portion of the shaft ( 10 ) and / or at least a portion of the cap ( 12 ) into one of four ring segment discs ( 20a . 20b . 22a . 22b ) trained receiving space ( 18 ), wherein a first ring segment disc ( 20a ) and a second ring segment disc ( 20b ) and form a first opening with each other and wherein a third ring segment disc ( 22a ) and a fourth ring segment disc ( 22b ) and form a second opening with each other, wherein the first ring segment disc ( 20a ) on the third ring segment disc ( 22a ) rests and the second ring segment disc ( 20b ) on the fourth ring segment disc ( 22b ) and the receiving space ( 18 ) comprises the first opening and the second opening; and wherein the insertion into the gap ( 14 ) the common insertion of at least a portion of the first ring segment disc ( 20a ) and at least a portion of the third ring segment disc ( 22a ) in the gap ( 14 ) and / or the common insertion of at least a portion of the second ring segment disc ( 20b ) and at least a portion of the fourth ring segment disc ( 22b ) in the gap ( 14 ). The method of claim 12, wherein the first ring segment disc ( 20a ) and the third ring segment disc ( 22a ) during insertion into the gap ( 14 ) maintain their relative position to each other and / or the second ring segment disc ( 20b ) and the fourth ring segment disc ( 22b ) during insertion into the gap ( 14 ) maintain their relative position to each other. Method according to claim 12 or 13, in which the removal of the cap ( 12 ) a rotational movement of the first ring segment disc ( 20a ) relative to the third ring segment disc ( 22a ) and / or a rotational movement of the second ring segment disc ( 20b ) relative to the fourth ring segment disc ( 22b ). A method according to claim 14, wherein the sliding of the cap ( 12 ) simultaneously with the rotational movement of the first ring segment disc ( 20a ) relative to the third ring segment disc ( 22a ) an axial movement of the first ring segment disc ( 20a ) relative to the third ring segment disc ( 22a ) along the longitudinal axis (Z) of the shaft ( 10 ) and / or in which the removal of the cap ( 12 ) simultaneously to the rotational movement of the second ring segment disc ( 20b ) relative to the fourth ring segment disc ( 22b ) an axial movement of the second ring segment disc ( 20b ) relative to the fourth ring segment disc ( 22b ) along the longitudinal axis (Z) of the shaft ( 10 ). Method according to one of claims 9 to 15, wherein the ring segment discs ( 20a . 20b . 22a . 22b ) when inserted into the gap ( 14 ) into slot-shaped recesses ( 44a . 44b . 45a . 45b ) at the top and / or bottom of the ring segment discs ( 20a . 20b . 22a . 22b ) engaging pin elements ( 40a . 40b . 42a . 42b ). A method of resistance welding, comprising: (a) repeatedly performing steps 1 to 3, wherein step 1 comprises feeding a pair of materials to a resistance welding apparatus having at least one welding gun having at least two opposing electrodes; Step 2 comprises compressing material and electrodes at a point; and step 3 comprises applying a welding current flowing through both electrodes and the material; and (b) after repeatedly performing steps 1 to 3, changing the electrode caps ( 12 ) wherein the detachment of an electrode cap ( 12 ) of an electrode shaft ( 10 ) comprises the method according to any one of claims 9 to 16. Method according to one of claims 9 to 17 using a device according to one of claims 1 to 8.

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