Device for guiding rounded borders through a welding zone

DESCRIPTION

The invention relates to a device for conducting rounded sheet metal work pieces through the welding zone of a machine for welding the longitudinal edges of the work pieces, with groups of mobile gluttonous elements that are facing each other with respect to each other. to the work pieces and exert radial guiding forces on these, the guide elements of each group being arranged in an endless chain that is driven around a drive wheel and a tensioning wheel and which has a chain branch that runs in the direction of movement of the work pieces and that goes supported by means of a rail on both sides of a plane containing the welding zone and which is perpendicular to the direction of movement mentioned.

A known device of this class (DE-AL29 07 391) serves to guide tubes when making a longitudinal seam weld. In this device there are two bearing units for each chain with guide elements, which are arranged on both sides for the purpose of adjusting the driving of the work pieces and can certainly be positioned as a whole one in relation to another. However, in this kind of guidance there is the difficulty that the guáa channel formed by the guáa elements is practically closed throughout its length and thus remains inaccessible. This manifests itself as disadvantageous in performing maintenance and adjustment work, as well as in the repair of breakdowns, for example when removing foreign bodies.

In another known device (DE-AL-25 59 671), which is used to drive rounded sheet helmets, that is, individual workpieces that follow each other, diabolic rollers will be arranged as guiding elements around of the axis of movement and are provided in part with an elastic and radial support. Such rotating guide elements around their own axes fulfill their mission impeccably when the helmets have a diameter of the order of magnitude of 50 mm or more, especially when the longitudinal edges of the helmets are welded in a crushed overlapping seam. However, difficulties may occur when the diameter of the helmets is less than 50 mm and / or the longitudinal edges of the helmets are butt welded between them, especially by laser beam. In such cases, the quality of the weld seam can be diminished by barely perceptible blows that occur each time one of the many roller-shaped guide elements arranged in the region of the welding zone rolls first on the leading end. and later on the back end of a helmet.

For this reason, the invention is based on the problem of configuring a device of the aforementioned class in such a way that the guide channel for the workpieces can be made accessible quickly and easily. In particular, the device should also be suitable for guiding consecutive individual workpieces (helmets) of small diameter of, for example, 32 to 25 mm and in particular should be suitable for laser welding of the longitudinal edges of such helmets. Small diameter helmets are necessary especially for electric battery housings.

The problem is solved according to the invention in a device of the genre mentioned at the beginning because at least one of the chains, together with the corresponding rail and the tensioning wheel, is tiltable around the corresponding drive wheel in the sense of departing of the opposite chain.

It is achieved with the invention that the guide elements, which form along the guide rails of the work pieces on both sides of the movement axis, can be separated from each other without complications to perform maintenance work or to remove parts of work eventually stuck. Thus, actions by way of blows on circulating helmets in the vicinity of the welding plane are avoided.

It is advantageous that each of the swiveling rails out along with the associated chain is supported radially on two springs that are offset from each other in the direction of transport and can be adjusted independently of each other. With this possibility of adjustment, it can be achieved in a particularly simple way that the longitudinal edges of the work pieces have in the welding zone a position exactly determined from one in relation to another, that is to say that they overlap in a certain amount when it should occur. an overlapping weld seam, or apply butt to each other when a butt weld seam should be formed, in particular with a laser beam.

In the middle longitudinal plane of the device according to the invention, as usual, a sliding rail that guides the longitudinal edges of the workpieces, especially a rail with a Z-shaped profile, which is usually called lane in Z. It is advantageous in this respect that, following another characteristic of the invention, a magnetic rail is arranged diametrically in front of the slide rail which additionally guides the work pieces.

Finally, it is advantageous that, upstream of the transport of the chains, a guide bushing which is funnel-shaped in the direction of movement of the workpieces and which has at least one axial groove along the length of the which can move a ratchet to fit consecutive work pieces between the chains. It is imaginable that the workpieces are transported in a known manner through the welding plane, for example by means of trailing bodies in reciprocating motion, or are transported only to the welding zone and then continue to be moved by electrode rollers.

When passing consecutive work pieces of given length, it is finally convenient that each of the rails extends uninterrupted and in a straight line between a beginning and an end, whose distance to the welding plane is greater than the length of each work piece indivi2

016 820 dual.

An exemplary embodiment of the invention is explained in more detail below with reference to schematic drawings. They show:

Figure 1, a device followed the invention in plan view,

Figure 2, the same device in partially disassembled state and partially in horizontal section,

Figure 3, the section in the vertical plane IIIIII of Figure 1,

Figure 4, the section in the vertical plane IVIV of Figure 1,

Figure 5, the section in the vertical plane vv of Figure 1, and

Figure 6, the device in a plan view corresponding to Figure 1, but in an open state.

The represented device has the function of driving the helmets 10 cylindrically rounded around an axis A, which, for example, consist of uncoated steel sheet or tinplate, such that its longitudinal edges 12 and 14, fixedly applied one to another, they can be welded together while the helmets 10 are moved forward along their axis A, from left to right in Figures 1 and 2, through a welding plane B perpendicular to the axis A. Such helmets are specially designed as housings for electric batteries.

The helmets 10, before they reach the device shown, have been wound by a rounding device of the usual construction class around a stationary lower arm 16 which extends parallel to the horizontal axis A in a usual manner through a bushing. glutton 18 also horizontal and penetrating centrally in the device shown. In the direction of transport of the helmets 10, downstream of the guide bushing 18, a sliding rail 20, also usual, of Z-shaped profile, in which the longitudinal edges 14 are guided, is fixed on the lower arm 16 and 16 of the helmets. The slide rail 20 ends slightly ahead of the welding plane B, in which a laser canon 22 is arranged, whose beam 24 is indicated in Figure 4. In the area of ​​the beam 24 the longitudinal edges 12 and 14 run between a front end section 26 of the lower arm 16 and a sliding skid 28 arranged above the west, both of which are bored in such a way that they do not hinder the passage of the beam 24 Vertically below, a refrigerated absorber 30 was arranged.

To make the helmets 10 pass through the guide bushing 18, a ratchet 32 ​​is provided, which can be moved in parallel with the axis A by means of a conventional drive device, not shown, for example of the type of a crank transmission, and that during its forward movement it always penetrates into the interior space of the guide bushing 18 through an axial groove 34 thereof. Each helmet 10 leaving the guide bushing 18 is seized by two groups of guide elements 36 which are arranged in endless chains 38.

The two stationary chains 38 symmetrically arranged in relation to the A axis in the operating position of the device, have chain branch silks parallel to this axis and circulating forward, and extend in a horizontal plane around two drive wheels 40 and two chain tension wheels 42. The chains 38 converge from the chain tension wheels 42 towards their chain branches parallel to the axle.

In the example shown both chains 38 are configured as triple roller chains; their links are joined together by means of articulation bolts 44 on which three respective rollers 46 are supported. Each of the guide elements 36 was fixed adjacent articulation bolts 44 and has a cylindrical seat surface 48 whose diameter coincides with the outer diameter of the helmets 10. Each of the helmets 10 is clamped on its two sides, with the hull length represented, by three respective guide elements 36 and driven along the axis A through the welding plane B. On the last of the three elements of respective guiding 36 a trawl o 50 is fixed. The trailing bodies 50 in the two chain branches parallel to the stationary axis face each other in pairs, so that each hull 10 is seized by a pair of trailing bodies 50 that are applied to its rear end, and, therefore, it is reliably moved through the welding plane B even when the radial forces with which the guiding elements 36 act on the helmets 10 through their application surfaces 48, they are too soft to generate sufficient friction forces to drag the hulls.

The magnitude of the aforementioned radial forces is determined by the fact that the straight chain branch of each of the two chains 38 is supported on a rail 52. Each of the rails 52 has three guide ribs 54 superimposed parallel to the axis. A, on which the rollers 46 of the corresponding chain 38 run. The length of the guide ribs 54 in front and behind the welding plane B is greater than the length of the helmets; as a consequence, each helmet 10 is guided free of trepidations by means of the guide elements 36 that accompany it, from an instant before the front end of the helmet reaches the welding plane B, until an instant after which its rear end has left the welding plane.

Each of the two rails 52 was guided in a movable manner between two sliding plates 56 which are fixed to two sides 58. In each of the rails 52 two threaded bolts 60 that extend in a horizontal plane radially with respect to the axis are screwed A and which are guided in a stile 62 fixed between the two corresponding sides 58. Between each of the two rails 52 and the corresponding amount 62, there are two compression springs 64 that are arranged around each of the threaded bolts 60 and that support the rail with a support force of the order of magnitude of, by example, 25 to 30 kg. Thus, the chain branch parallel to the axis in each of the two chains 38 was supported by the corresponding rail 52 so that it can be

016 820 adjusted in a radial direction with respect to the A axis.

In the vicinity of the rails 52, another upright 66 is fixed on the respective corresponding sides 58 in which the corresponding chain tensioning wheel 42 is movably guided, this being also supported by a compression spring 68.

The two drive wheels 40 will be fixed to two vertical trees 70, each of which is supported by a sleeve 72. The two sleeves 72 will be fixed to a common stationary base plate 74. The two pairs of sides 58 corresponding to each other are supported on a respective tree of the two trees 70, so that they can swing around the corresponding tree away from each other to move from their operating position shown in Figures 1 to 5 to a maintenance position.

In Fig. 6 a pair of sides 58 together with the corresponding parts of the device, in particular the chain 38 at the junction of the guide elements 36 and the chain tensioning wheel 42, has swung to the maintenance position, while the other pair of sides 58 together with the corresponding parts of the device still occupies its operating position. On the upper side 58 of one of the two pairs of sides a lock plate 76 is fixed on which a traction anchor 78 is pivotally supported. On the upper side 58 of the other pair of sides a correspondingly fixed one lock plate 80 which in the operating position of the device can be tightened together with the lock plate 76 by means of the traction anchor 78 and a threaded handle 82 screwed on this. The distance between the chain branches parallel to the axis of the two chains 38 in the operating position is determined by means of an adjustable stop screw 84 which is screwed into the lock plate 80 and encounters one of its front surfaces against the lock plate 76.

The two trees 70 can be driven in opposite directions with exactly identical speed; To this end, an adjustable electric motor 86 is connected through a toothed pinion 88 and a toothed belt 90 with two sprockets 92 that are fixed on each of the trees 70. The toothed belt 90 hugs in addition to a deflection wheel 94 which is supported by the base plate 74.

The drawings show how four helmets 10 run one after the other at a distance established the device described above and are then guided by the guide elements 36 in the chain branches parallel to the axis. In the welding zone the longitudinal edges 12 and 14 are welded together by means of the beam 24. The welding helmets 10 are then transported between the chain branches parallel to the shaft and finally delivered a relatively large distance from the welding plane B, for example to a further processing device.

To further improve the guidance of the helmets 10, a magnetic rail 96 on struts 98 has been fixed below the slide rail 10. The helmets 10 slide on the magnetic rail 96 in an area diametrically opposite its longitudinal edges 12 and 14 , before they are captured by guide elements 36 and while they are thus captured. This ensures that the helmets 10 occupy exactly a predetermined position with respect to the guide elements.

36. The magnetic force is chosen so that the frictional force between each hull 10 and the magnetic rail 96 coincides at least approximately with the sum of the frictional forces between the longitudinal edges 12 and 14 and the sliding rail 20. In this way , the moments of these friction forces are at least approximately in equilibrium and, therefore, the fences 10 cannot be tilted.

016 820