WO2004054738A1

WO2004054738A1 - Wobble joining device

Info

Publication number: WO2004054738A1
Application number: PCT/EP2003/013991
Authority: WO
Inventors: Jochen Hain
Original assignee: Newfrey Llc
Priority date: 2002-12-17
Filing date: 2003-12-10
Publication date: 2004-07-01
Also published as: AU2003292220A1; DE10258928A1

Abstract

The invention relates to a device (10; 114) for wobble-joining at least two plate-shaped pieces (52, 54), especially sheets. Said device comprises a base frame (12; 115), a die (74) that can be displaced by means of an axial drive (28, 30, 22; 118) along a main joining axis (56) towards the pieces (52, 54) or away from them and that can be set into a wobbling motion about the main joining axis (56) by means of a wobble drive (28, 30, 34, 70; 110). The device further comprises a dolly (18) on the side of the pieces (52, 54) opposite the die (74). The die (74) and at least one wobble train (70) of the wobble drive (28, 30, 34, 70; 120) are mounted on the joining head (26; 116) which is disposed on one end of a first arm (24) that extends at an angle to the main joining axis (56). The dolly (18) is disposed on one end of the second arm (16) that extends at an angle to the main joining axis (56), said first and said second arm (24, 16) being mounted on the base frame (12; 115).

Description

Swash joining device

The present invention relates to a device for the wobble joining of at least two plate-shaped workpieces, in particular sheets, to one another, with a base frame, a stamp, which can be moved towards and away from the workpieces by means of an axial drive along a main joining axis and which can be moved away from one another The wobble drive can be set into a wobble movement around the main joining axis, and a counter-holder on the side of the workpieces opposite the punch.

Such a wobble joining device is known from DE 100 32 816 A1.

Various methods are known for joining two plate-shaped workpieces, in particular metal sheets, to one another. Examples of such processes are spot welding, riveting and stud welding. In the latter case, a nut is welded onto one of the sheets and the workpieces are screwed together.

In addition to the classic riveting processes, in which the workpieces have to be drilled beforehand, so-called punch riveting has been in use for several years. Punch rivets are generally used with punch rivets, but also hollow rivets and full rivets, which are pressed into the two or more workpieces by means of a punch, without a hole having to be drilled beforehand. The hollow cylindrical end face of the rivet element bends during the joining process and thus connects the two workpieces "in a virtually positive manner". Although there are punch rivet elements that are hollow throughout (cf. DE 100 32 816 A1), so-called semi-rivet elements whose head side is closed are currently predominantly used (cf. for example DE 199 27 103 A1).

Furthermore, it is known to connect two plate-shaped workpieces by means of so-called clinching. A hollow die is arranged on the lower workpiece as a counter-holder. A stamp is pressed into the two workpieces from above, so that a depression running through both workpieces is pressed therein. As an example, reference is made to the documents DE 198 40 780 A1, DE 199 29 778 A1 and DE 199 45 743 A1 for this prior art. Finally, the so-called wobble rivet is known as a further connection technique. This is a kind of combination of wobble punch riveting and clinching. A solid solid element is pressed into the workpiece arrangement by means of a stamp, a counter-holder being arranged on the underside of the workpiece arrangement. The full rivet element remains in the deformed workpiece arrangement as a kind of "lost stamp". With regard to this prior art, reference is made, for example, to DE 101 02 712 A1.

The three joining processes described are all quasi form-fitting connections and belong to the field of mechanical joining technology, also called joining technology.

The axial forces in the main joining direction required to establish the joining connection are usually considerable. For all three processes, modifications of this technology have therefore been developed in which the stamp of the joining device is moved in a wobble manner. This enables the high joining forces to be reduced many times over. The above documents all work according to the wobble process. It is both known to incline the punch at an angle with respect to the main joining axis and to rotate it on a circular path about this axis. This is often referred to as wobble joining. In another embodiment, the stamp describes a rosette path (hypocycloid), a planetary gear often being used as the wobble gear. This technique is also known as orbital joining. In the present context, these types of movements are generally summarized under the term "wobble joining". The decisive factor here is that the punch does not perform a purely axial movement, but rather both an axial movement and a movement in which the punch is inclined with respect to the main joining axis.

Nevertheless, the forces occurring in the axial direction are also not insignificant in the case of wobble joining. The devices manufactured so far are of a relatively solid, stationary design. In addition, these known wobble joining devices are generally only used to connect continuously flat workpieces. As soon as the plate-shaped components are bent, the joining process is difficult or even impossible. This applies in particular because the wobble joining devices in the area of the joint have a rather voluminous construction, in particular due to the wobble mechanism required. Finally, the known devices are designed exclusively for wobble punch riveting, clinching or wobble riveting. The joining process itself is labor-intensive since the respective rivet elements are usually to be positioned by hand first.

In contrast, it is the object of the present invention to provide an improved wobble joining device.

According to a first aspect of the present invention, this object is achieved by the wobble joining device mentioned at the outset, wherein the punch and at least one wobble mechanism of the wobble drive are mounted on a joining head which is arranged on one end of a first arm which extends transversely to the main joining axis , and wherein the counter-holder is arranged at one end of a second arm which extends transversely to the main joining axis, the first and the second arm being mounted on the base frame.

Due to the configuration of the wobble joining device according to the invention, it is possible to use the wobble joining device universally.

The above object is further achieved according to a second aspect of the present invention by the wobble joining device mentioned at the outset, wherein the punch and at least one wobble mechanism of the wobble drive are mounted on a joining head, the joining head having a hold-down device which can be placed on the upper plate-shaped workpiece and which by means of a elastic device is biased relative to the joining head in the main joining direction, and wherein the wobble mechanism is arranged above the elastic device.

With this embodiment, the wobble mechanism is arranged on the joining head relatively far from the joining point. As a result, the joint head is small in the area of the joint. The wobble joining device can consequently also be used in situations in which the plate-shaped workpieces are bent adjacent to the joining point.

According to a third aspect of the present invention, the above object is achieved by the wobble joining device mentioned at the beginning, the wobble joining device being designed for wobble joining by means of auxiliary joining elements, such as, for example, rivet elements. According to a fourth aspect of the present invention, the above object is achieved by the wobble joining device mentioned at the outset, wherein the punch and at least one wobble gear of the wobble drive are mounted on a joining head and a plurality of different counterparts can be attached to the base frame, which are used for different joining methods are designed which include wobble punch rivets, wobble rivets and wobble rivets. This measure allows the same basic device to be used for different wobble joining processes. If the wobble drive is not started, the device can also be used for punch riveting or clinching.

It is understood that the inventions according to the first to fourth aspects of the present invention can be combined with one another in an advantageous manner. Any combinations of only two or more aspects of the present invention are possible.

In the wobble joining device according to the first aspect of the present invention, it is particularly preferred if the axial drive is integrated in the base frame and is designed to move the first arm and the second arm towards or away from one another. With this embodiment, the mass and the volume of the joining head can be reduced. As a result, the wobble joining device can also be used in more inaccessible places. Due to the lower mass of the joining head, the arms can also be made lighter with the same stability.

According to a further preferred embodiment according to the first aspect of the present invention, a wobble drive motor of the wobble drive is integrated in the base frame and coupled to the wobble gear in the joining head via a coupling gear. With this embodiment, the mass and the volume of the joining head are reduced even further, with the resulting advantages. It is particularly advantageous if the coupling gear has a belt transmission that extends along the first arm. In this way, the motor power of the wobble drive motor can be transmitted to the joining head in an efficient and weight-saving manner.

According to an alternative embodiment according to the first aspect of the invention, the first arm and the second arm are rigidly coupled to one another on the base frame. The wobble drive and the axial drive are preferably integrated in the joining head. This embodiment is structurally inexpensive to implement. Overall, it is advantageous in the first aspect of the present invention if an axial drive motor of the axial drive and a wobble drive motor of the wobble drive are formed by the same motor. As a result, the wobble joining device can be given a lower weight and volume overall. Suitable clutches and / or gears can be present in order to branch the power of the motor for the axial drive and the wobble drive.

It is also particularly preferred if an axial drive motor of the axial drive is an electric motor. This can be easily controlled and only requires an electrical supply network to supply energy.

Overall, it is also advantageous in the first aspect of the present invention if the base frame is attached to a robot arm of a robot. As a result, the wobble joining device can also be used, for example, in industrial assembly, in particular in the manufacture of motor vehicle bodies. Because in this area of application it is necessary to move the respective joining device to any inaccessible places in any spatial position.

In the second aspect of the present invention, it is advantageous if the elastic device has a spring assembly. In this way, the elastic pretensioning of the hold-down device can be implemented in a structurally simple manner.

It is particularly advantageous if the stamp is passed through the spring assembly. This measure makes it possible to make the joining head particularly slim in the area of the joining point, so that joining connections can also be implemented in inaccessible places.

In the third aspect of the present invention, it is advantageous if the joining head has a holding device for an auxiliary joining element. This makes it possible to first fix an auxiliary joining element in the joining head by means of the holding device. The auxiliary joining element therefore does not have to be positioned manually between the punch and the workpiece arrangement. It is particularly advantageous if the holding device has at least two jaws which are elastically prestressed in the radial direction and are designed to engage radially on the auxiliary joining element. The radially preloaded jaws make it possible to hold the rivet element in the holding device without the holding device having to be moved by a motor. It is particularly advantageous if the jaws are pretensioned by means of an elastic ring element which engages the jaws, preferably from the outside on the jaws. This measure enables the elastic prestressing of the jaws to be implemented in a structurally simple manner.

In the third aspect of the present invention, it is also of particular advantage if the at least two jaws are floatingly supported in the radial direction. This ensures that the holding device, and thus the auxiliary joining element, can be centered by the stamp. Furthermore, the floating mounting enables the stamp that passes through the holding device, that is to say between the jaws, to perform wobbling movements without damaging the holding device.

It is also advantageous if the jaws have a holding section for the auxiliary joining element and if the jaws expand conically above the holding section. As a result, the holding device can be centered as an alternative to the punch centering or in addition to this. Furthermore, the insertion of the stamp from above into the holding device is facilitated.

Overall, it is furthermore advantageous in the third aspect of the present invention if the joining head has a feeding device for feeding auxiliary joining elements into the holding device. This measure allows the process of inserting an auxiliary joining element into the holding device to be automated. It is particularly advantageous if the feed device has a channel into the joining head which opens above the holding device. This makes it possible to insert the auxiliary joining elements into the holding device from above.

In the embodiment with radially prestressed jaws, the auxiliary joining element then takes the same path into the holding device as the stamp. It is also advantageous if the channel is oriented obliquely from above towards the holding device. This makes it possible to insert the auxiliary joining elements from above into the holding device in an approximately correct axial orientation. No means are required to turn the auxiliary joining element inside the joining head.

According to a further preferred embodiment according to the third aspect of the present invention, the feed device has a feed pipe which is nal is insertable. This makes it possible to guide the auxiliary joining element in the correct position directly up to the holding device or into the holding device. The stamp can either be withdrawn from the holding device. However, it is particularly preferred if the punch is spaced from the top of the holding device in a rest position of the joining head in order to be able to feed the auxiliary joining element without collision. Here, the stamp is then inserted into the holding device in that the hold-down device is displaced relative to the axially fixed stamp when it is placed on the workpiece arrangement.

According to a further preferred embodiment according to the third aspect of the present invention, the holding device is designed to hold an auxiliary joining element elastically in each case, the feeding device having means which are designed to press an auxiliary joining element into the holding device on the ram side. This can advantageously take place in that the means for pressing the auxiliary joining element into the holding device are designed as compressed air means, in particular in connection with the feed pipe.

As an alternative to this or in addition to this, the means for pressing the auxiliary joining element into the holding device can also have a plunger. A plunger allows the auxiliary joining element to be inserted into the holding device in the correct position in terms of design. In this case, it can preferably be recognized in a simple manner by the displacement path of the plunger which takes place whether the feeding process was actually successful or not. It is particularly advantageous if the tappet is displaceably mounted in the feed tube. It is particularly advantageous if the tappet is elastic at least in sections, in particular in the direction transverse to its longitudinal extent. This makes it possible to also feed the auxiliary joining elements through a curved feed pipe. The plunger can be designed to be elastic either as a whole or only in sections, for example only at a front end at which the deflection from an oblique feed channel to the main joining direction takes place.

According to a further preferred embodiment, the tappet has a dome-shaped tip. The dome-shaped tip ensures that the auxiliary joining elements do not tilt when deflected from an inclined feed channel into the main joining direction. By means of the dome-shaped tip, an axial force can always be transmitted to the auxiliary joining element during insertion into the holding device, parallel to the main joining direction. It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own without departing from the scope of the present invention.

Embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

1 shows a schematic side view of a first embodiment of the wobble joining device according to the invention;

FIG. 2 shows a schematic sectional view through a lower part of the joining head of the wobble joining device of FIG. 1;

Fig. 3 shows a detail III of Fig. 2;

3a shows a representation corresponding to FIG. 3 with an alternative holding device;

4 shows an exploded perspective view of the holding device of the joining head of FIG. 2;

5 shows a view of the joining head of FIG. 2 from below, with the holding device closed;

6 shows a view corresponding to FIG. 5, with the holding device partially open;

7 shows a view corresponding to FIG. 5, with the holding device open;

FIG. 8 shows a schematic sectional view through a feed pipe of a feed device of the wobble joining device of FIG. 1;

Fig. 9 is a side view of an alternative stamp for the feed tube of Fig. 8;

10 shows a further embodiment of a wobble joining device according to the invention; 11 shows a further embodiment of a wobble joining device according to the invention; and

FIG. 12 is a sectional view of the feed device of the wobble joining device of FIG. 1.

In Fig. 1, a first embodiment of the wobble joining device according to the invention is generally designated 10.

The wobble joining device 10 has an elongated base frame 12 with a housing 14. A first arm (hereinafter second arm) 16 extends from the base frame 12, at the end of which a counter-holder 18 (die) is fixed. The counter-holder 18 can be exchanged in order to be able to carry out various wobble joining methods, including wobble rivets, wobble rivets, wobble rivet rivets and punch rivets. Furthermore, a displacement block 20 is mounted on the base frame 12 so as to be displaceable in the axial direction, specifically by means of a linear guide 22. A further arm 24 (hereinafter referred to as first arm) 24 is attached to the displacement block 20. At the end of the first arm 24 there is a joining head, which is generally designated 26 in FIG. 1.

A motor 28, here an electric motor 28, is arranged on the base frame 12. Instead of an electric motor, however, a fluidic motor or the like can be provided. Above the motor 28, a gear 30 is provided which translates the speed of the electric motor 28. The output of the transmission 30 is coupled to the displacement block 20, so that the displacement block 20 can be displaced on the linear guide 22 by means of the electric motor 28. A spindle drive (not shown) can be used for this purpose. Axial movements of the displacement block 20 lead to axial movements 32 of the joining head 26.

The drive power of the electric motor 28 is further branched in the transmission 30 to a belt drive which has a belt 34. The belt 34 extends parallel to the first arm 24 and serves to give a stamp of the joining head 26, which will be described below, a wobbling movement. Instead of a belt drive, any other type of coupling gear can be used. A feed device 36 is provided on the side of the joining head 26. The feed device 36 has a feed tube 38, which points obliquely downwards and can be inserted into a mouthpiece 40 of the joining head 26, as is indicated schematically at 39.

The feed device 36 also has a feed interface 42 which can be connected to a conventional feed unit (not shown). The conventional feed unit can feed auxiliary joining elements (e.g. rivet elements) to be used in the joining process to the feeding device 36, for example by means of compressed air.

On a side of the base frame 12 facing away from the arms 16, 24, a supply interface 44 is also provided, via which the wobble joining device 10 can be connected to supply lines and control lines of a control system (not shown in more detail).

Furthermore, a holder 46 is shown in FIG. 1, on which the wobble joining device 10 can be attached. The holder 46 is fixed at the end of a one-part or multi-part robot arm 50 of a robot 48, which is shown schematically in FIG. 1.

By means of the robot 48, which has a suitable control system, the wobble joining device 10 can be used as an assembly tool, for example in the manufacture of bodies for motor vehicles.

At 52 and 54 two plate-shaped workpieces are shown in the form of metal sheets, for example two metal sheets to be connected to a vehicle body, which can be made of steel or aluminum, for example. The wobble joining device 10 is moved to a desired joining location 55 by means of the robot 48 such that the joining head 26 is arranged above the upper workpiece 52 and the counter-holder 18 below the lower workpiece 54. The position of the wobble joining device 10 is controlled by means of the robot 48 such that a main joining axis 56 running through the joining head 26 and the counter-holder 18 is perpendicular to the workpieces 52, 54 at the joining location 55.

The actual joining process is carried out by lowering the joining head 26 onto the counter-holder 18 by means of the displacement block 20. Simultaneously with this axial movement 32 of the joining head 26, a punch arranged in the joining head 26 is moved into one by means of the wobble drive (via motor 28 and belt 34) Staggered movement. Alternatively, the tumbling movement of the plunger can also take place with a time delay, that is to say a certain time after the initiation of the axial movement and / or after certain force limits have been exceeded (which can be determined, for example, by means of the motor current).

The joining head 26 is explained below using the application example of wobble punch rivets. However, it goes without saying that simply by replacing the counter-holder 18, the joining head 26 can also be used for other wobble joining methods, for example for wobble rivets or wobble rivet runners.

As explained above, the wobbling movement reduces the axial forces during the joining process. The result of this is that the wobble-joining device 10 can be made lighter and less voluminous overall. As a result, a robot 48 with lower performance requirements can be used. In addition, the stresses occurring at the joint location are lower than with a standard joint connection, which is carried out purely axially. The lower joining forces make it possible to make the arms 16, 24 less rigid. As a result, the arms 16, 24 can be formed with a lower mass. Alternatively or in addition to this, the arms 16, 24 can be made longer, so that there is a greater throat depth.

The length of the arms can be, for example, in the range of at least 40 cm, in particular at least 50 cm. As a result, joining operations can also be carried out at relatively inaccessible locations, in particular at a relatively large distance from the joining location 55 from an edge of the workpieces 52, 54.

The arrangement of the motor 28 in the region of the base frame 12 and the fact that the joining head 26 is moved on the base frame 12 by means of the displacement block 20 results in a slim or flat design of the joining head 26. This also contributes to the fact that joining connections are made places that are difficult to access, e.g. in automotive engineering inside the body.

Fig. 2 shows the lower end of the joining head 26 in a sectional view. The joining head 26 has a housing section 60 of an essentially hollow cylindrical configuration. A hold-down 62 is axially displaceably mounted on the housing section 60. The hold-down device 62 is designed to contact the upper workpiece 52 with its end face 64. The hold-down device 62 is arranged above the hold-down device 62 in the interior of the housing section 60 Spring assembly 66 in the main joining direction 56 biased to the counter-holder 18. The spring assembly 66 can be, for example, a packet of disc springs with a central recess. Alternatively, it can be a coil spring or the like. The hold-down device can also be pressed on by hydraulic or pneumatic means.

If, during an axial stroke of the joining head 26, the holding-down device 62 contacts the upper workpiece 52 with its end face 64, while the joining head 26 continues to move, the holding-down device 62 dodges into the housing section 60 against the force of the spring assembly 66. This is shown schematically at 68 shown. Above the spring assembly 66, the joining head 26 has a wobble gear 70, which can be designed in a conventional manner, for example as a ring gear or a planetary gear.

An output of the wobble mechanism 70 is connected to a plunger 74 which generally extends axially downward. The wobble mechanism 70 gives the punch 74 a wobble movement 72 around the main joining axis 56. The stamp 74 passes through the spring assembly 66 without touching it. An end face 76 of the punch 74 is arranged in a starting or rest position (shown in FIG. 2) of the hold-down device 62 at a distance from a punch rivet element 78 to be used in the joining process. In this starting or rest position of the hold-down 62, the punch 74 is arranged coaxially to the main axis of the joining. This makes it possible to feed the punch rivet element 78 by means of the feed tube 38, which is introduced into the mouthpiece 40 via a channel (not shown in FIG. 2).

The area of the mouthpiece 40 of the hold-down device 62 is shown in greater detail in FIG. 3. The punch rivet element 78 shown there is designed as a semi-hollow rivet, with a forward-extending hollow cylinder section 79 and a head section 80, the top surface of which is designed as a closed surface on which the end face 76 of the punch 74 can engage. The punch rivet element 78 is held in the mouthpiece 40 by means of a holding device 82.

The holding device 82 (see also FIG. 4) has four jaws 84 arranged approximately in a circular shape. The jaws 84 are floatingly supported in a cavity 86 of the mouthpiece 40 in the radial direction. The cheek elements 84 have a common annular groove 89 on the outside, into which an elastic ring element, for example a spring ring 88, is inserted. The spring rings 88 ken 84 compressed radially inwards, but can also be moved elastically radially outwards, as indicated schematically in Fig. 4.

The jaws 84 each have an inner holding section 90. The holding sections 90 are adapted to hold the head section 80 of the punch rivet element 78 between them elastically. Below the holding section 90, the jaws 84 each have an inwardly projecting projection, which together form an annular lug 91. The hollow cylinder section 79 passes through the ring nose 91 without contact; but it can also rest on the ring nose 91. However, the ring nose 91 prevents a punch rivet element 78 held in the holding device 82 from slipping downward.

Above the holding section 90, the jaws 84 together form an insertion section 92 which widens conically upwards. At its end facing the jaws 84, the mouthpiece 40 has a centering ring which projects into the insertion section 92 and has a frustoconical outer surface. The jaws 84 bear against the centering ring 93 when they are brought into the position shown in FIG. 5 by the spring ring 88. As a result, the jaws 84 center on the centering ring 93.

Between the holding section 90 and the insertion section 92, the jaws 84 furthermore form an inwardly projecting ring projection 94. The ring projection 94 engages over the head section 80 of the punch rivet element 78 and thus prevents the latter from escaping upward from the holding device 82, for example in the case of the Joined head 26.

Above the holding device 82, the mouthpiece 40 has an interior space 96 which widens conically upwards. The interior 96 opens out towards the holding device 82 in a cylindrical guide section 98. The housing section forming the guide section 98 has axial projections on which the holding device 82 is centered by itself with its insertion section 92 in the idle state.

In the rest position shown, the end face 76 of the stamp 74 is arranged clearly above the guide section 98. Provided on the mouthpiece 40 is a feed channel 100 which leads obliquely from above into the interior 96 and via which the feed pipe 38 can be inserted into the interior 96 without colliding with the stamp 74.

3a shows an alternative embodiment of a mouthpiece 40a. The construction and the mode of operation of the mouthpiece 40a correspond to the design of the mouthpiece 40 of FIG. 3. For the mounting of cylindrical auxiliary joining elements 78a, the holding device 82a has modified jaws 84a. The inner contour thereof, including the holding section 90a, the ring projection 91a and the ring nose 94a, is adapted such that a cylindrical auxiliary joining element 78a can now be held elastically.

The process of feeding a punch rivet element 78 into the holding device 82 is explained below with reference to FIGS. 3 and 4 and FIGS. 5 to 7.

Starting from the illustration in FIG. 3, it is assumed that there is no punch rivet element 78 in the holding device 82. In the following, the feed pipe 38 is introduced into the interior 96 from above at an angle via the feed channel 100, as is shown schematically at 101. As soon as one end of the feed tube 38 shown in FIG. 3 lies over the holding device 82, a punch rivet element 78 is fed over the feed tube 38. The hollow cylinder section 79 is first inserted between the jaws 84, possibly centered by the insertion section 92 (cf. FIG. 5).

As soon as the head section 80 abuts the insertion section 92, the jaws 84 elastically expand radially outward, as shown in FIG. 6. By further applying supply pressure from above to the punch rivet element 78, this finally snaps behind the ring projection 94. The jaws 84 are pressed radially inward by means of the spring ring 88 and thus hold the head section 80 firmly between them. The feed tube 38 is then withdrawn again from the feed channel 100 in order to clear the way for the stamp 74.

In the subsequent joining process, as already explained above, the joining head 26 is moved towards the workpiece arrangement 52, 54 until the end face 64 of the hold-down device 62 hits the upper workpiece 52. As the axial movement 32 continues, the hold-down device 62 is pressed inward into the housing section 60, so that the position of the punch rivet element 78 held by the holding device 82 remains constant with respect to the workpiece arrangement 52, 54. Due to the further axial stroke, the punch 74 is lowered further until it is finally guided through the guide section 98, on the insertion section 92 of the jaws 84. Here, the jaws 84 are in turn expanded radially. The holding section 90 releases the punch rivet element 78 so that it slides down through an opening 102 and comes to rest on the upper workpiece 52. When the axial movement continues, the end face 76 of the stamp 74 finally touches the top of the head section 80, the jaws 84 remaining in an expanded state, as is shown schematically in FIG. 7.

This is followed by the joining process already described above, with continuation of the axial movement and combined wobbling movement of the punch 74. The mouthpiece 40 has the lower opening 102, so that the punch 74 can move up to the top of the upper workpiece 52 around the punch rivet element 78 to fit flush into the workpiece assembly 52, 54. The counter-holder 18 forms a die for the joining process.

As can be seen in particular in FIGS. 3 and 4, the end of the punch 74 acting on the punch rivet element 78 tapers from the end face 76 upwards in the direction toward the punch center. The taper is formed in the area of the stamp 74 which penetrates into the holding section 90. The taper is preferably chosen so large that the end portion of the plunger 74 does not or only slightly moves the jaws 84 during the wobbling movement. This protects the jaws 84 and prevents wear.

After the joining process has taken place, the joining head 26 is lifted off the workpiece arrangement 52, 54 by means of the motor 28, the spring assembly 66 again moving the hold-down device 62 into the rest position, which is shown in FIG. 2.

8 shows the feed pipe 38 in greater accuracy. In general, it is possible to convey punch rivet elements 78 into the holding device 82 via the feed pipe 38 by means of compressed air. In the embodiment presented, however, the punch rivet elements 78 are pressed into the holding device 82 by a plunger 104, which is displaceable in the feed tube 38.

The tappet 104 has a dome-shaped tip 106 at its front end in order to ensure that the punch rivet elements 78 during the transition from the oblique orientation of the feed tube 38 to the axial orientation in the holding insert. do not tilt direction 82. For this purpose, the feed pipe 38 is provided at its front end with a suitable bend, designated 108 in FIG. 8.

9 shows an alternative embodiment of a plunger 104 '. The tappet 104 ′ has a section 110 which is elastic in the transverse direction at its front region and a dome-shaped tip 106 is arranged at the front end thereof. This makes it possible to also drive through stronger bends 108 of a feed pipe 38 by means of the plunger 104 '.

10 finally shows an alternative embodiment of a wobble joining device 114 according to the invention. The wobble joining device 114 has a base frame 115, from which a lower arm 16 '(second arm) and an upper arm 24' (first arm) extend rigidly. The second arm 16 ′ is constructed similarly to the arm 16 of the wobble joining device 10.

As stated, the first arm 24 is rigidly fixed to the base frame 115. At the end of the first arm 24, a joining head 116 is arranged, which has both an axial drive 118 for axially moving the punch 74 (setting feed and setting force) and a wobble drive 120, which is designed to press the punch 74 via an angular head 119 to cause a wobble. The wobble drive 120 and the angle head 119 also move during the joining process.

The embodiment in FIG. 10 can be mounted on a robot 48 just like the wobble joining device 10 of FIG. 1. The axial drive 118 can be designed as an electrically driven spindle.

11 shows a further alternative embodiment of a wobble joining device 124. The wobble joining device 124 has a base frame 126 which has a lower C-bracket half 128 and an upper C-bracket half 130. The bracket halves 128, 130 are mutually displaceable parallel to the joining direction. A frame motor 132, which can set up a rapid feed, is used for this purpose. With it, the two bracket halves 128, 130 are moved towards and away from each other. This makes it possible to set different opening widths of the bracket halves 128, 130. The rack motor 132 drives a linear drive 136. Guides 134 prevent the C-bracket halves 128, 130 from twisting. They also absorb the moments caused by the setting force. 12 shows the feed device 36 of FIG. 1 in section. The feed device 36 has a housing 140 which is fastened to the hold-down device 62 of the joining head 26 and is slidably mounted on the housing section 60 with the aid of a bearing section 142. A receiver 144 is movably mounted in the housing 140. A curved feed channel 146 is attached to the receiver 144 and has at its free end the feed interface 42 for connecting a flexible line for feeding auxiliary joining elements 78. The receiver 144 is fixedly connected to the feed pipe 38, which is mounted so that it can move longitudinally in the housing 140.

The receiver 144 is connected to a cylinder tube 148 on the side opposite and coaxial to the feed tube 38. The cylinder tube 148 contains the plunger or loading pin 104 and a piston 150 for moving the loading pin 104. Via connections 152, 154, the piston 150 is on opposite sides with a drive fluid, e.g. Compressed air, can be acted upon.

A cylinder bore 156 is provided in the housing 140 parallel to the cylinder tube 148. In the cylinder bore 156 there is a further piston 158 with a piston rod 160, which is fastened in the housing 140 to the receiver 144. By applying a working fluid, e.g. Compressed air, which can be supplied via a connection 162, the piston 158 can be moved in the direction of the receiver 144 against the force of a compression spring 164.

An auxiliary joining element 78 is fed in several stages in the feed device 36. In the first stage, the auxiliary joining element 78, coming from the direction of arrow 165, is conveyed by compressed air through the feed channel 146 into the receiver 144. The auxiliary joining element 78 is held in the receiver 144 by a stop 166 and a resilient locking element 168 in front of the end 106 of the charging pin 104. In the next stage, the piston 158 is pressurized. As a result, he displaces the receiver 144 and the parts connected to it in relation to the housing 140 in the direction of the arrow 165. As a result, the feed pipe 38 penetrates into the channel 100 of the mouthpiece 40 and arrives with its outlet opening in the mouthpiece 40 via the holding device 42 In the third stage, the piston 150 is pressurized via the connection 154, so that the latter pushes the auxiliary joining element 78 into the holding device 82 with the aid of the charging pin 104. In the fourth stage, the connection 162 is connected to an unpressurized space and the receiver 144 is moved back into the starting position shown by the spring 164. Furthermore, by pressurizing the connector 152 and by connecting the connection 154 to an unpressurized space, the pistons 150 together with the charging pin 104 are returned to the starting position shown. As soon as the charging pin 104 has reached its starting position, the next auxiliary joining element 78 is fed via the interface 42.

It goes without saying that the feed device 36 can also be used in the wobble joining devices 114 and 124 of FIGS. 10 and 11.

It also goes without saying that the wobble joining devices 10, 114, 124 according to the invention are equally suitable, if the punch 74 can also be brought into a position aligned with the main joining direction 56 (for example in the case of orbital joining), standard joining connections (for example standard punch rivet connections, standard clinch connections, Standard clinch rivet connections).

Claims

claims

1. Device (10; 114) for wobbling together at least two plate-shaped workpieces (52, 54), in particular sheets, with a base frame (12; 115), - a stamp (74) which is operated by means of an axial drive (28, 30 , 22; 118) can be moved towards or away from the workpieces (52, 54) along a main joining axis (56) and which can be made to tumble around the main joining axis (28, 30, 34, 70; 120) by means of a wobble drive (28, 30, 34, 70; 120). 56) can be moved around, and - a counter-holder (18) on the side of the workpieces (52, 54) opposite the stamp (74), characterized in that the stamp (74) and at least one wobble mechanism (70) of the wobble drive (28 , 30, 34, 70; 120) are mounted on a joining head (26; 116) which is arranged at one end of a first arm (24) which extends transversely to the main joining axis (56), and that the counter-holder (18) one end of a second arm (16) is arranged, which extends transversely to the main joining axis (56), de r first and second arms (24, 16) on the base frame (12; 115) are stored.

2. wobble joining device according to claim 1, characterized in that the axial drive (28, 30, 22) integrated in the base frame (12) and is designed to the first arm (24) and the second arm (16) towards each other or from each other to move away.

3. wobble joining device according to claim 1 or 2, characterized in that a wobble drive motor (28) of the wobble drive (28, 30, 34, 70) in the

Base frame (12) is integrated and is coupled via a coupling gear (30, 34) to the wobble gear (70) in the joining head (26).

4. wobble joining device according to claim 3, characterized in that the coupling gear (30, 34) has a belt transmission (34) which extends along the first arm (24).

5. wobble joining device according to claim 1, characterized in that the first arm (24 ') and the second arm (16') on the base frame (115) are rigidly coupled together.

6. wobble joining device according to claim 5, characterized in that the wobble drive (120) and the axial drive (118) are integrated in the joining head (116).

7. wobble joining device according to one of claims 1-6, characterized in that an axial drive motor (28) of the axial drive (28, 30, 22) and a wobble drive motor (28) of the wobble drive (28, 30, 34, 70) by the same motor (28) are formed.

8. wobble joining device according to one of claims 1-7, characterized in that an axial drive motor (28) of the axial drive (28, 30, 22; 118) is an electric motor.

9. wobble joining device according to one of claims 1-8, characterized in that the base frame (12) on a robot arm (50) of a robot (48) is fixed.

10. wobble joining device according to the preamble of claim 1 and in particular according to one of claims 1-9, characterized in that the stamp (74) and at least one wobble mechanism (70) of the wobble drive (28, 30, 34, 70; 120) on one The joining head (26; 116) is mounted such that the joining head (26; 116) has a hold-down device (62) which can be placed on the upper plate-shaped workpiece (52) and which is opposed to the joining head (26) in the main joining direction (66) by means of an elastic device (66). 56) is biased and that the wobble mechanism (70) is arranged above the elastic device (66).

11. wobble joining device according to claim 10, characterized in that the elastic device (66) has a spring assembly (66).

12. wobble joining device according to claim 11, characterized in that the stamp (74) is guided through the spring assembly (66).

13. wobble joining device according to the preamble of claim 1 and in particular according to one of claims 1-12, characterized in that the wobble joining device (10; 114) for wobble joining by means of auxiliary joining elements, such as e.g. Rivet elements is formed.

14. wobble joining device according to claim 13, characterized in that the joining head (26; 116) has a holding device (82) for an auxiliary joining element (78).

15. wobble joining device according to claim 14, characterized in that the holding device (82) has at least two jaws (84) which are elastically prestressed in the radial direction and are designed to engage radially on the joining aid element (78).

16. wobble joining device according to claim 15, characterized in that the jaws (84) by means of an elastic ring element (88) which engages the jaws (84) are elastically biased.

17. wobble joining device according to claim 15 or 16, characterized in that the at least two jaws (84) are mounted floating in the radial direction.

18. wobble joining device according to one of claims 15 - 17, characterized in that the jaws (84) have a holding section (90) for the auxiliary joining element (78) and that the jaws (84) expand conically above the holding section (90) ,

19. wobble joining device according to one of claims 14 - 18, characterized in that the joining head (26; 116) has a feed device (36) for feeding auxiliary joining elements (78) into the holding device (82).

20. Tumble joining device according to claim 19, characterized in that the feed device (36) has a channel (100) into the joining head (26) which opens above the holding device (82).

21. wobble joining device according to claim 20, characterized in that the channel (100) is oriented obliquely from above to the holding device (82).

22. wobble joining device according to claim 20 or 21, characterized in that the feed device (36) has a feed tube (38) which can be inserted into the channel (100).

23. Tumble joining device according to one of claims 20-22, characterized in that the holding device (82) is designed to hold an auxiliary joining element (78) in each case elastically, and that the feed device (36) has means (104) which are designed to press an auxiliary joining element (78) into the holding device (82) on the ram side.

24. wobble joining device according to claim 23, characterized in that the means for pressing the auxiliary joining element into the holding device are designed as compressed air means.

25. wobble joining device according to claim 23, characterized in that the means (104) for pressing the joining aid element (78) in the holding device (82) have a plunger (104).

26. wobble joining device according to claim 22 and 25, characterized in that the plunger (104) in the feed tube (38) is slidably mounted.

27. wobble joining device according to claim 25 or 26, characterized in that the plunger (104 ') is at least partially elastic.

28. A wobble joining device according to one of claims 25-27, characterized in that the plunger (104) has a dome-shaped tip (106).

29. wobble joining device according to the preamble of claim 1 and in particular according to one of claims 1-28, characterized in that the punch (74) and at least one wobble mechanism (70) of the wobble drive (28, 30, 34, 70; 120) on one Joining head (26; 116) are mounted and that a plurality of different counterholders (18) can be attached to the base frame (12; 115), which are designed for different joining methods, which include wobble punch rivets, wobble rivets, wobble rivet bumps and punch rivets.