DE3910099C2 - - Google Patents

Description

The invention relates to a device for producing Plastic containers, especially large containers.

When producing large plastic containers from plastic slabs, which in flat or arched form the walls, the floor and also, if necessary, the lid of such a container form, the welding of the plastic parts comes a very high importance because when welding these parts resulting welds are exposed to very large forces. The strength and tightness of such seams are special very high requirements when it comes to wastewater Containers in which the waste water is collected before they are supplied to cleaning stages so that the leakage of a such a container could cause environmental damage. In These containers are also the chemicals for this Cleaning processes are stored and sometimes even Treatment processes carried out. The tightness of the container therefore plays a major role.

While the plates forming the container jacket frequently their ends butt welded together are common  the wall parts on a flat plate forming the floor placed so that the edge of the base plate over the outside surface of the wall parts protrudes, so that the surfaces of the Wall parts and the bottom of a mostly right angle form with each other in a sweat connecting these parts can be put. The production of such welds can with the help of known and commercially available extrusion that take place at the end of an extruder tube a shoe have, which is intended to the angle between the to be pushed into adjacent surfaces so that together with these surfaces it has a cavity with limited essential triangular cross section, in which the as Welding agent used plastic from the extruder can be pressed. A hot air blower, the blowpipe next to it opens the extruder tube, causes sufficient heating of the plastic parts to be welded together, so that the plastic supplied by means of the welding extruder perfectly with the material to be welded together Plastic parts connects.

Such a connection made with the help of a welding extruder Plastic parts have the required properties but working with such a sweatex truder very exhausting because he hand on the weld must be led along. The extruder is supported with the sweat attached to the end of his welding tube shoe in the angle between the adjoining waiters surfaces of the workpieces to be welded together, so that the welder does not take the entire weight of the welding extruder needs to carry. A steady feed of the extruder however requires a great deal of skill and attention in ver commitment with a still considerable effort,  so that a welder working with such a device must allow frequent breaks. It goes without saying even that with a large container with a diameter of 2300 mm and a welding time of 60 to 75 min per weld this seam by hand not in one piece and not with consistent quality can be produced because the Welders often have to interrupt work to relax.

A welding device is known (US-PS 38 95 991), with the plastic lid is welded to a plastic container can be. The device has a work table for this to accommodate the parts to be welded together, the parts in the pre-assembled state, i.e. H. with over the Lids placed on containers, clamped in a horizontal position will. This lying cylindrical container is now in Dre hung and the parts to be welded by means of two welding devices descending from above onto the container welded together. This device has the disadvantage that they only accept containers with a limited diameter can, d. H. only very small containers can be produced with it will. A disadvantage has also been shown that at non-circular containers the weld seams of different thicknesses have, because the distance between the welding head of the Welding device and the welding point not all over Welding process is constant, d. H. the extruder is not compliant is stored so that it the non-circular course of the container could follow.

The invention is therefore based on the object of a device for the manufacture, in particular welding, of To create plastic containers with one over the whole  Length of the weld, extending uniform seam, is achieved even with non-round containers.

This object is achieved with a device for the production of plastic containers, in particular Large containers, with a work table, such as one in a horizontal, the parts to be welded with their axes in vertical Direction receiving turntable or perpendicular to one Support movable carriage, the support in height adjustable and arranged next to the work table, with a sliding on the support towards the work table Slide, a welding extruder mounted on the slide with one in the direction of movement of the sled extending and oblique to the surface of the work table directed extruder tube, with a load on the slide Drive device and with a controller for controlling the Movement of the carriage, with the welding extruder opposite the support is stored so resiliently that he with the End of his extruder tube with a predetermined force the welding point lies on.

The device according to the invention therefore makes a han conventional welding extruder use and includes facilities which allow the welding extruder to be in the correct position to bring to the workpiece, there under the necessary To maintain contact pressure and at the same time to generate one Relative movement between extruder required for the weld and manufacture the workpiece using the turntable. On this The flat plastic floor for the plastic now becomes a turntable placed on the container and placed on the coat. Is now either the mantle is not centered against the ground or has the coat deviating from the circular shape  chende, z. B. elliptical shape, it is still ensured that creates a clean weld with the welding extruder as it is resilient to the support, and thus the changes with the end of his extruder tube the distance of the weld from the support, the z. B. from the elliptical shape, can follow, so that the Welding head of the extruder tube always with a predetermined There is force on the weld and therefore no weld metal wells up next to the weld. Therefore, with the Device according to the invention produce welds that have the same high quality over their entire length.

The device according to the invention also has the advantage on that on the turntable, containers with different dimensions sions can be put on and the welding device on these dimensions are easily adaptable. With this Device are preferably containers with a diameter made from 800 to 2600 mm and a height of approx. 2500 mm. However, the device is not for the manufacture of containers limited with these dimensions. For containers with high Weight can even be fixed with an additional fixation Rotary table can be dispensed with. Also a previous assembly of the two parts to be welded together is eliminated because they are already placed on top of each other on the turntable how they should be welded later.

The above object is also achieved according to the invention by a device for producing plastic containers, especially large containers, with a work table, such as one in horizontal, the parts to be welded with their axes in vertical turntable or a vertical to two supports movable slides, the supports in  adjustable in height and arranged next to the work table, with one each on the supports towards the work table sliding carriage, one each on the carriage assembled welding extruder with one in the direction of motion tion of the carriage extending and obliquely to the surface of the Work table directed extruder tube, one each Sled loading drive device and with a Control for controlling the movement of the carriage, the a welding extruder via the one external support to the Weld and the other welding extruder over the other Support from the inside is brought up to the welding point, and the welding extruders compared to the supports such are resiliently stored that with the end of their Extruder tubes with a given force on the weld lie on.

This other device according to the invention also makes a commercial welding extruder use and includes a directions that make it possible, next to one, on the outside provided welding extruder another welding extruder the inside of the container to be arranged so that he rests with a predetermined force at the welding point and this can be tracked in the direction of the extruder tube. With this device, both inside and External seams are created, also at the turntable not exactly centered containers or for containers that have a have a shape different from the circular shape, a clean and constant quality especially over its entire length Sending weld seam can be generated. By means of this device tion, it is also possible to have two containers pushed into each other coats with an outer and an inner seam to each other  weld as described in more detail below becomes.

According to an advantageous embodiment, the Devices be constructed as special machines in which the support is at a stationary location opposite the work table Stand is located, and support on a trolley is preferred arranged, which enables the support with the on it arranged facilities on the edge of a stationary Driving along the workbench. An arrangement of the latter Art is particularly beneficial when straightforward To produce welds between flat plastic parts are. A further training provides that the support for this is set to be lowered into the interior of a container be so that a weld on the inside of one a wall can be made on a floor. Further are surfaces of plastic that adjoin one another at an angle share also connectable in that thick-walled plastic parts overlapping each other, such that the one of the surfaces of the end face of one part is formed, which the Overlaps the edge of the other part.

Another advantage of the device according to the invention is that mobile application, e.g. B. in workshops, on construction sites etc., d. H. directly before the later place of use of the containers, see above that cumbersome transports of large containers are avoided can be.

With the two aforementioned devices, the work table also be designed as a sled, the z. B. Rectangular shaped parts records that welded together to a rectangular container  should be. The sled drives past the support, so that the weld on the welding shoe of the Extruder is guided along.

As mentioned above, the welding extruder is said to be sufficient great force on the contiguous surfaces of art parts of fabric are applied so that one of these surfaces and of the welding shoe attached to the end of the extruder tube closed room that is under a certain pressure the plastic supplied by the welding extruder can be filled. Serves to maintain this pressure in the horizontal direction the one mentioned above, the sled with a constant force stressful drive device. To avoid this pressure in Verti to be able to maintain the direction of the kal without compli graceful control devices are required preferred embodiment of the invention of the welding extruder compared to the support in the direction of the support movement resiliently mounted that he with the end of his welding tube comes into contact with the workpiece with a predetermined force.

Similar to machine tools, the support can be radial stationary rotary table can be arranged displaceably. Such Arrangement is particularly advantageous when plastic parts welded together with widely varying dimensions should be.

In general, a welding extruder is based on the angle aligning surfaces so that his Ex truderrohr approximately along the bisector between the adjacent surfaces extends. But it can In individual cases it may be advisable to deviate from this rule give way, for example to adapt to certain loads,  to produce asymmetrical seams and it can also be the angle very different between the adjacent surfaces values, even if this angle is often 90 ° wearing. In view of these options, this looks preferable Embodiment of the invention that the welding extruder one opposite the sled by one to the work surface parallel axis pivotable support is attached. This Carrier makes it possible to always opti for the welding extruder Male angular position in relation to the work table and thus opposite the contiguous surfaces of the ver adjust welding plastic parts. Another, the Measure used to optimally adjust the welding extruder is that the welding extruder on a compared to the Carriage rotatable about an axis perpendicular to the plane of the carriage Plate is arranged.

At least one welding wire can still be on the support drum attached. This ensures that the welding wire to be inserted into the welding extruder is the loading movements of the welding extruder attached to the support constantly follows and no feeding disruptions can occur. There can be one at the welding wire inlet of the welding extruder Device for cleaning the welding wire can be arranged. Such a device, which is a simple Ab streif-cuff can be very important because yourself in the case of an operation which is not particularly monitored Device on the welding wire can accumulate a lot of dust contamination of the extruder and faulty Can lead to a weld.

The drive device for the carriage can in particular simply a substantially constant air pressure  operated pneumatic cylinders include. Such a cylinder essentially ensures a larger stroke constant contact pressure dependent on air pressure, so that the Welding extruder fluctuations in the distance of a plastic part can easily follow from the edge of the workbench. To under to ensure constant air pressure in all circumstances, can the pneumatic cylinder preferably attached to the support air pressure tank upstream.

In a further embodiment of the invention, the device comprise a control and regulating device that is entered Setpoints for operating parameters and on the components of the Device arranged responses and in particular is set up to the operating states of the welding extruder and the device for generating the relative movement between Monitor workbench and support.

The operating states of the welding extruder include in particular special temperature and flow rate of the extruder, the amount and temperature of the one used to preheat the weld Gases and last but not least the monitoring of the welding wire feed. The relative movement between workbench and support must be very be finely adjustable, because this relative movement exactly on the Delivery rate of the extruder must be coordinated so that a uniform weld seam without sink marks and also without edges disturbed by overflowing material. Next For example, there may be a sensor that detects the Compressed air supplied to the drive device and the length and especially monitored the completion of a weld.

An Aus characterized by its special simplicity leadership form of the invention is that it moves  work table and a forklift next to it includes, the lifting platform forms the support on which the facilities described above.

According to an advantageous embodiment, the support for the inner welding extruder as in the container jacket from above engaging frame formed. Here is what Frame advantageous from a vertical tower with outrigger and one, provided at the free end of the boom, the Elevator holding welding extruder. About that as a torsionally rigid Construction trained frame is the, the inner seam producing welding extruder introduced into the interior of the container and there exactly and with a predetermined force on the sweat held. The welding extruder can be lifted be positioned exactly in the vertical direction and according to Be completion of the welding process to a position above the loading raised and by moving the frame out the container area.

This ensures an exact adjustment of the welding extruder tube relieved that the elevator at its free, the boom opposite end of the carrier and / or the rotatable plate to which the welding extruder is fixed. Means of the wearer are accurate settings regarding the angular position the container wall or the container bottom and by means of the rotary The plate is a vertical alignment of the extrusion derrohres achievable with respect to the weld. Here is the Welding extruder over an angle of at least 45 degrees fixed to the support so as to be pivotable with respect to the horizontal. This ensures that a with the welding extruder Weld, e.g. B. in the welding of the container shell can be generated with the container bottom, in which the  Welding extruder angled at an angle of 45 degrees downward welding position, but also other welding positions are ingestable, in which the welding extruder at an angle of about 45 degrees upwards on the Weld is directed. This is especially the case Case when a second, in the lower container jacket inserted upper container jacket to be welded. A low driving force for the elevator is achieved that this by means of a in the vertical tower of the frame provided balance weight via pull ropes balanced in the front end of the boom is. This weight balanced boom can be advantageous be moved by means of an actuator with a slip clutch. The servomotor is used to deliver the elevator exactly and thus possible of the welding extruder on the welding point, whereby the weight balance of the elevator enables that the welding extruder of the welding point also in vertical Direction can follow without the weight of the elevator Extruder must be raised.

The invention is described below with reference to the drawing illustrated embodiments described in more detail and he purifies. Those to be found in the description and the drawing Features can be in individual embodiments of the invention individually or in any combination Find application. It shows a schematic representation

Figure 1 is a side view of a device according to the invention with a work table shown only in detail according to a first embodiment.

Fig. 2 is a top view of the device of Fig. 1; and

Fig. 3 is a side view of another Ausfüh approximate shape.

The device shown in FIGS . 1 and 2 comprises a work table 1 designed as a turntable 42 , which is mounted on a base 2 containing a drive for the turntable. Such rotary tables with drive are commercially available.

A height-adjustable support 3 , which is formed by the lifting platform of a forklift 4 , is assigned to this work table 1 . This forklift 4 is placed next to the work table 1 so that its direction of travel is approximately radial to the work table 1 .

On the support 3 formed by the lifting platform, a slide 6 is slidably mounted by means of a linear guide 5 , the direction of displacement of which, in the position of the forklift 4 shown in the drawing, is also directed radially to the circular work table 1 . On this carriage 6 , a welding extruder 7 is mounted in such a way that its extruder tube 8 can be brought into engagement with a workpiece attached to the work table 1 . In order to enable the welding extruder to be optimally aligned with the workpiece, the welding extruder is fastened on the carriage 6 by means of a plate 9 which can be rotated about an axis perpendicular to the plane of the carriage, and the welding extruder is furthermore on a carrier 10 arranged on the plate 9 attached, which is pivotable relative to the plate about a horizontal, perpendicular to the direction of movement of the carriage 6 axis 11 .

As a welding extruder 7 , a commercial device is used which, in a manner not shown, has a motor-driven extruder screw and a heating device in a housing, so that cold-fed plastic is verified in the extruder and fed by the extruder screw 7 through the extruder tube 8 to the welding point 12 can. In addition, the welding extruder comprises a hot air generator with a tube 13 , which directs the hot air generated at the welding point to warm it up to the welding temperature, so that a fusion with the plastic tube supplied via the extruder tube 8 can take place.

The welding extruder 7 used in the illustrated embodiment is supplied with the plastic required to produce the weld in the form of a wire 17 which is located on a drum 18 attached to the support 3 . The wire 17 extending from the drum 18 to the inlet 14 of the welding extruder passes through a wire cleaner 16 fastened to the welding extruder 7 by means of an arm 15 , which contains an annular stripping element in a manner not shown, for example a felt ring, which also has a ring Detergent could be soaked to ensure that the material fed to the extruder is free of contaminants, especially dust, which could adversely affect the quality of the weld seam produced.

In order not to have to take a break in work at the end of the welding wire wound on the welding wire 18 , a holder for a second welding wire drum 19 is arranged on the support 3 , from which the welding wire 20 can be pulled off and fed to the extruder 7 if the end of the welding wire 17 on the first drum 18 is determined. The empty drum 18 can then be replaced by a full one, so that work can continue here without interruption when the welding wire 20 on the drum 19 is exhausted.

Preferably, a monitoring element (not shown) is provided and connected to a control panel, which gives a signal when the welding wire drum 18 is empty, so that, for. B. before the end of the last meter, the welding wire of the second welding wire drum 19 can be brought up, whereby interruptions in the welding can be avoided.

The device shown in the drawing is particularly suitable for welding the wall 21 of a container with a circular cross section to a flat bottom 22 . For this purpose, the bottom 22 , as shown in the drawing, is placed concentrically on the work table 1 and the container wall 21 forming a cylindrical jacket is placed on the floor. In this case, the cylinder jacket is fixed to the container bottom 22 by individual, affixed by hand welding points or a "root pass." 21 Such a fixation neither guarantees a tight connection between the container jacket and the bottom, nor does it have the strength to withstand the high loads to which the weld seam is exposed when the container is full.

For permanent and tight connection of the container wall 21 and the on the container wall protruding with its edge 23 bottom 22 of the wall 21 and the bottom 22 is placed a seam with high material strength and high resistance by means of the welding extruder 7 in the angle between the adjacent surfaces, which also ensures the necessary tightness. The welding extruder 7 carries at the end of the extruder tube 8 a welding shoe 24 usually made of PTFE, which together with the adjacent sections of the wall 21 and the protruding edge 23 of the bottom 22 defines a cross-sectionally triangular cavity into which the extruder 7th supplied, plasticized by the action of heat, which is usually made of the same plastic as the wall 21 and the bottom 22nd By means of the pipe 13 in the angle directed, the welding point leading hot air flow, the plastic of the wall 21 and the bottom 22 is softened so much that a melting takes place with the plastic pressed under high pressure into the angle and the angle between the bulge filling a bordering wall part becomes an integral part of wall 21 and floor 22 . Here ge equip the rotary plate 9 described above, a precisely radial alignment of the extruder tube 8 to the rotatable work table 1 and the pivotable support 10 an adjustment of the extruder tube 8 at a desired angle to the wall parts to be welded together. Even if the surfaces of the plastic parts to be welded to one another usually meet at an angle of 90 ° and the welding seam is to cover the two surfaces over the same width, so that an orientation of the extruder tube 8 at an angle of 45 ° to the surface of the work table 1 is the most abundant, other angles between the wall may be possible in the individual case and it is also un symmetrical seams conceivable to their production, the extruder barrel 8 surface at a 45 ° deviating angle to the upper must be aligned of the worktable. 1 The weld seam thickness is proportional to the wall thickness of the plastic plates to be welded. With a constant welding wire supply, the speed of rotation of the turntable (in an embodiment not shown, the speed of movement of the work table designed as a slide) can be continuously adjusted to welding shoes of different sizes and this speed can be monitored.

As mentioned above, the welding shoe 24 must bear under a certain pressure on the circumference of the cylindrical wall 21 and also on the upper side of the edge 23 , so that the space delimited by the welding shoe 24 , which serves as a casting mold, is sealed off from sufficiently and In this room no injected plastic spills out of the side of the shoe. In the illustrated embodiment, the necessary contact pressure against the cylindrical wall 21 , that is, radial to the work table 1 , generated in that a pneumatic cylinder 25 is arranged between the support 3 and the carriage 6 , which acts with constant air pressure in such a sense is that the carriage 6 with constant force with respect to the support 3 to the outside and thus presses the extruder tube 8 with its shoe 24 against the cylinder wall 21 of the container. The stroke of the pneumatic cylinder 25 ensures a compensation of changes in distance between the support 3 and the cylindrical wall 21 due to errors in the central arrangement of the cylindrical wall 21 on the rotating work table 1 and in the event of deviations of the cylindrical wall 21 from a precisely circular contour. Here, the be operated with constant air pressure pneumatic cylinder 25 attached to the support 3 air pressure container 26 , which serves as a buffer for changing the amount of air, which is associated with a movement of the carriage 6 relative to the support 3 .

So that the pneumatic cylinder 25 does not need to have an excessively large stroke, but nevertheless a considerable radial adjustment of the slide 6 with respect to the support 3 is possible, for the end of the piston rod 27 of the pneumatic cylinder 25 several connection points 28 are provided on the support 3 , which are between the elements the linear guide 5 are easily accessible and therefore enable a gradual displacement of the carriage by moving the piston rod 27 from one connection point to another, while the pneumatic cylinder 25 allows movement of the carriage in the area between two connection points.

The pressure of the welding shoe 24 on the edge 23 of the bottom 22 can be done simply by lowering the support 3 formed by the lifting platform of the forklift 4 and lifting the vertical support of the support 3 so that the support under its own weight, reduced by the friction on the vertical guide 41 of the forklift truck rests on the edge 23 of the base 22 , on the other hand also by the fact that a further pneumatic cylinder 75 is provided on the carrier 10 , the direction of action of which runs parallel to the direction of the welding tube 8 , ie in the direction of the arrow 76 . In the case of hydraulic vertical drive, the hydraulic cylinder of the forklift serving to lift the support 3 could be pressurized, which leads to a precisely defined differential force between the lifting force and the weight of the support 3 with its superstructures, which then becomes effective as a pressing force on the welding shoe 24 . But it would also be possible to support the welding extruder flexibly in the vertical direction with respect to the support 3 or the slide 6 , for example using vertical guides arranged between the rotatable plate 9 and the carrier 10 , which deflect the extruder upwards against a predetermined force enable with which the extruder then always lies on the top of the plastic part lying on the work table.

It is readily apparent that the device described allows the fully automatic production of the weld between the wall parts 21, 22 when the work table 1 is set in slow rotation, so that the plastic parts 21, 22 to be bonded to each other ver along the entire circumference of the are fed past the welding shoe 24 of the welding extruder 7 bottom 22, during which welding extruder is in operation while the plasticized plastic in the preheated by a hot air stream, pressed by the welding shoe 24 be confined space. But it is also readily understandable that the conveying speed of the welding extruder 7 and the rotational speed of the work table 1 must be coordinated very precisely so that on the one hand the material supplied by the welding extruder 7 is sufficient to fill the space delimited by the welding shoe 24 under pressure and thereby To produce a solid weld of impeccable quality, so that, on the other hand, no welding material spills out of the confined space that could also give rise to an unclean seam. There must therefore be a fine adjustment for the rotational speed of the work table and / or the speed of the Förderextrwin the welding extruder 7 is provided. This adjustment and adjustment of the rotational and conveying speed can be carried out while observing the weld seam from a control panel 31 which is arranged on the support 3 on the side of the carriage 6 opposite the welding wire drums 18, 19 and is accordingly located at one point , from which the weld can be observed well. The control panel 31 also contains other operating switches, in particular for lowering and raising the support 3 , for switching on the compressed air for the pneumatic cylinder 25 , for the radial setting of the slide 6 , for switching the extruder 7 on and off with its hot air blower and the like. Furthermore, such a control panel 31 can also contain instruments which indicate the size of monitored operating values, such as, for example, the temperatures of the hot air used for preheating and the plastic supplied to the welding point from the extruder 7 , the pressure generated by the extruder, the degree of filling of the welding wire drums and the like Furthermore, proximity switches 32 can be provided on the circumference of the work table 1 , which, in conjunction with suitable sensors, cause the welding process to be stopped when the rotating work table 1 has completed a complete revolution, or which trigger a signal shortly beforehand that the user of the device thereof below judges that a weld is almost completed, so that the user can then complete the weld by hand control. All in all, it goes without saying that all of the variables that are decisive for the execution of a welding process of high quality are monitored by sensors and the actual values measured in the process can be used in a customary manner to prevent inadmissible deviations of these actual values from given by suitable control and regulating devices Avoid target values and in this way enable largely automatic operation of such a device.

FIG. 3 shows another embodiment of the welding apparatus, with which both an outer seam as an inside seam on the container 33 can also be generated. For the production of the outer seam, a first part 29 of the device is provided, which corresponds to the exemplary embodiment explained above, the same parts being provided with the same reference numerals. In addition to the first part 29 of the device, this second embodiment has a second part 30 with which a weld seam 34 or 35 can be produced in the interior of the container 33 . This second part 30 of the device essentially consists of a forklift 36 on which a frame 38 serving as support 37 is fixed. The frame 38 consists of a vertical tower 39 and a horizontal arm 40 which is aligned essentially radially to the turntable 42 . At the free end of the horizontal arm 40 , a vertical elevator 43 is provided, at the free end 44 of which a holder 45 is provided for receiving a welding extruder 46 . This holder 45 consists of a welding extruder 46-carrying substrate 47 on which the welding extruder 46 is guided by a carriage 48 in the direction of arrow 49 by means of a pneumatic cylinder 50 slidably. The carrier 47 is in turn fixed via legs 51 to a receptacle 52 , the legs 51 being pivotable and fixable on the receptacle 52 in such a way that the welding extruder can assume 46 positions in which it is at least 45 degrees downwards as well as horizontally can be pivoted upwards by at least 45 degrees with respect to the horizontal. The receptacle 52 is in turn attached to a plate 53 which is fixed on a carriage 54 so as to be rotatable about its vertical axis. The carriage 54 is mounted by means of a pneumatic cylinder 55 in a slide plate designed as a slide guide 56 in the effective direction of the pneumatic cylinder 55 slidably ver. On the support plate 56 engage four push rods 57 (of which only two are drawn), which in turn are guided in the bearing 58 at the free end of the boom 40 in the vertical direction. Furthermore, a traction cable 59 , which is guided over deflection rollers 60 and whose other end is connected to a counterweight 61 , engages approximately in the middle of the upper end of the carrier plate 56 . This counterweight 61 is guided in the vertical tower 39 in guides 62 in the vertical direction. The weight of the counterweight 61 corresponds approximately to the weight of the elevator 43 consisting of the push rods 57 and the holder 45 with the welding extruder 46 attached thereto, so that the latter is guided in a balanced manner over the elevator 43 at the outer end of the boom 40 . Also connected to the counterweight 61 is an endless chain 66 which is guided around a chain wheel 64 and around the drive of a servomotor 65 and by means of which the counterweight 61 can be displaced via the servomotor 65 . For safety reasons, the servo motor 65 has a slip clutch. For safe support, the forklift 36 is provided with a right and a left support 67 , which ensure a secure stand of the second part 30 of the device.

As already mentioned above, the welding extruder 46 can be introduced into the interior of the container 33 by means of the elevator 43 , and there the welding shoe 24 can be brought exactly to the welding point 12 by means of an adjustment of the holder 45 . For this purpose, the welding extruder 46 can be rotated via the plate 53 rotatable about its vertical axis and can be guided radially to the welding point in the direction of the arrow 68 by means of the slide 54 guided in the carrier plate 56 via the pneumatic cylinder 55 . About the pneumatic cylinder 50 and the pneumatic cylinder 55 , the welding shoe 24 can be held with a predetermined force on the welding point 12 and in particular when the welding position changes, which z. B. in the case of eccentric arrangement of the container on the turntable 42 or in the case of non-circular containers, follow, the welding shoe 24 always pressing with the predetermined force on the weld.

With this second part 30 of the second embodiment of the device, both, as shown in FIG. 3, internal weld seams 34 with which the container wall 21 is welded to the container bottom 22 can be produced, but it is also possible to produce weld seams which As shown in the right-hand part of the container 33 shown in FIG. 3, connect two container shells inserted into one another. For this purpose, the welding extruder 46 is pivoted about 90 degrees about the axis 68 in such a way that the extruder tube 8 points in the direction of the arrow 69 , ie is directed upward at an angle of about 45 degrees with respect to the horizontal. With the welding extruder 46 arranged in this way, the weld seam 35 can now be produced, with which the inner container jacket 70 is fixed on the inside of the container wall 21 . The outer seam 71 is welded to the first part 29 of the device according to the invention, the support 3 being adjusted in height via the vertical guide 41 on the forklift 4 , so that the welding shoe 24 of the welding extruder 7 in the direction of arrow 72 at the welding point for the welding seam 71 comes to rest. Here too, the peripheral speed of the turntable 42 can be adapted to the thickness of the weld seams 35 and 71 .

Finally, the welding extruder 46 is supplied via an inlet, a welding wire 73, which is also wound on a welding wire drum 74, as shown in FIG. 3, the device is arranged on the support 3 of the first part 29, but however at can be arranged anywhere else. This embodiment also has a control panel 31 with which the welding processes can be monitored.

Claims (16)

1.Device for producing plastic containers, in particular large containers, with a work table ( 1 ), such as a rotary table ( 42 ) which accommodates the parts to be welded with their axes in the vertical direction, or a slide which can be moved perpendicular to a support ( 3 ), wherein the support ( 3 ) is adjustable in height and arranged next to the work table ( 1 ), with a slide ( 6 ) which can be displaced on the support ( 3 ) in the direction of the work table ( 1 ), and a welding extruder mounted on the slide ( 6 ) ( 7 ) with an extruder tube ( 8 ) extending in the direction of movement of the carriage ( 6 ) and directed obliquely to the surface of the work table ( 1 ), with a drive device loading the carriage ( 6 ) and with a controller ( 31 ) for controlling the movement of the carriage ( 6 ), the welding extruder ( 7 ) being so resiliently mounted with respect to the support ( 3 ) that it ends at the end of its extruder tube ( 8 ) rests on the weld ( 12 ) with a predetermined force. 2. Device for the production of plastic containers, in particular large containers, with a work table ( 1 ), such as a rotary table ( 42 ) that can accommodate the parts to be welded with their axes in the vertical direction or one that is perpendicular to two supports ( 3, 37 ) Slide, the supports ( 3, 37 ) being adjustable in height and arranged next to the work table ( 1 ), each with a slide ( 6, 54 ) which can be displaced on the supports ( 3, 37 ) in the direction of the work table ( 1 ), Each has a welding extruder ( 7, 46 ) mounted on the slide ( 6, 54 ) with an extruder tube ( 8 ) extending in the direction of movement of the slide ( 6, 54 ) and directed obliquely to the surface of the work table ( 1 ), one each of the slide ( 6, 54 ) loading drive device and with a controller ( 31 ) for controlling the movement of the carriage ( 6, 54 ), the one welding extruder ( 7 ) via the one support ( 3 ) from the outside the welding point ( 12 ) and the other welding extruder ( 46 ) are brought from the inside to the welding point ( 12 ) via the other support ( 37 ), and the welding extruder ( 7, 46 ) is so flexibly mounted in relation to the supports ( 3, 37 ) are that they rest with a predetermined force on the weld ( 12 ) with the end of their extruder tubes ( 8 ). 3. Apparatus according to claim 1, characterized in that the support ( 3 or 37 ) is arranged radially to the stationary rotary table ( 42 ). 4. Device according to one of the preceding claims, characterized in that the welding extruder ( 7 or 46 ) on a relative to the carriage ( 6 or 54 ) about a parallel to the rotary table surface axis ( 11 or 68 ) ver pivotable support ( 10 or 47 ) is attached. 5. Device according to one of the preceding claims, characterized in that the welding extruder ( 7 or 46 ) is displaceably mounted on the carrier ( 10 or 47 ) by means of a pneumatic cylinder. 6. Device according to one of the preceding claims, characterized in that the welding extruder ( 7 or 46 ) is arranged on a plate ( 9 or 53 ) rotatable relative to the slide ( 6 or 54 ) about an axis perpendicular to the slide plane. 7. Device according to one of the preceding claims, characterized in that the drive device for the carriage ( 6 or 54 ) comprises a pneumatic cylinder ( 25 or 55 ) operated essentially with constant air pressure. 8. Device according to one of the preceding claims, characterized in that the control and regulating device ( 31 ) responds to input target values for operating variables and to sensors arranged on the components of the device and is in particular set up to determine the operating states of the welding extruder ( 7 or 46 ) and the device for generating the relative movement between the rotary table ( 1 ) and support ( 3 or 37 ). 9. Device according to one of the preceding claims, in particular according to claim 3, characterized in that the support ( 3 or 37 ) is formed by the lifting device of a forklift ( 4 ) or 36 ) set up next to the turntable ( 42 ). 10. The device according to one or more of claims 2 to 9, characterized in that the support ( 37 ) for the inner welding extruder ( 46 ) is designed as a frame ( 38 ) engaging from above in the container ( 33 ). 11. The device according to claim 10, characterized in that the frame ( 38 ) from a vertical tower ( 39 ) with boom ( 40 ) and one, provided at the free end of the boom ( 40 ), the welding extruder ( 46 ) holding elevator ( 43 ) consists. 13. The apparatus according to claim 11, characterized in that the elevator ( 43 ) at its free, the arm ( 40 ) facing away from the end ( 44 ) has the carrier ( 47 ) and / or the rotatable plate ( 53 ). 13. Device according to one of claims 2 to 12, characterized in that the welding extruder ( 46 ) is pivotally attached to the carrier ( 56 ) over an angle of at least 45 degrees on both sides of the horizontal. 14. The device according to one of claims 11 to 13, characterized in that the elevator ( 43 ) on a in the vertical tower ( 39 ) of the frame ( 38 ) before seen balance weight ( 61 ) via pull cables ( 59 ) weight balanced in the front end of Boom ( 40 ) is guided. 15. The device according to one of claims 11 to 14, characterized in that the elevator ( 43 ) is adjustable in height via a servomotor ( 65 ) with a slip clutch. 16. Device according to one of the preceding claims, characterized in that the device as a mobile Insert device is designed.