EP0401510B1 - Machine for filling packages with flowable products - Google Patents

Abstract

A machine is described for filling packages with flowable product, a filler pipe (13) with a piston (29) and piston rod (30), provided with an overpressure valve (32) on the outlet side, is connected on the inlet side to a feed line (20). In order for cleaning to be possible in combination with a relatively simple construction, even with the mass-production filling of a plurality of packages simultaneously and without extensive installation work, provision is made according to the invention for the feed line (20) to be connected to a preliminary feed tank (22), which is arranged above it and linked to a feed line (50) for cleansing agent with an inlet valve, for a shut-off valve (25) to be provided in the line (24) to the filler pipe (13), and for the overpressure valve (32) to be closeable under the prestress of a spring (33). <IMAGE>

Description

The invention relates to a system for filling packs with flowable filling material with piston and piston rod, wherein an essentially vertically arranged filling pipe, provided with a pressure relief valve that can be closed by a spring, is supplied on the inlet side via a feed line, with a flow container, which is connected to a supply line for cleaning agents is connected, and with a shut-off valve arranged in the line from the flow tank to the filling pipe.

It is known to produce packs in a machine and to fill them in downstream processing stations, among other things. These filled packs are sealed, rearranged, arranged, repackaged or the like in further downstream processing stations. DE-A-20 64074 discloses a system for filling packs similar to the type mentioned above, milk being filled into packs made of coated paper that are open on one side. In the known system, in addition to a metering tube, there is the cylindrical space of a metering piston pump, in which a piston with a piston rod is arranged at the bottom in such a way that it can be moved from an enlarged part down to the top of the pump body. During this upward movement, the milk is pressed through a horizontal connecting line into the parallel and also vertically arranged filling pipe, through which the filling can take place. A pressure valve is arranged at the upper end of the filling pipe, and a suction valve is arranged above the metering piston pump in a line to a storage container arranged at the top. Both work together and are necessary for the dosed filling. For cleaning in the known device, two connecting lines connected to the underside of the piston pump are required, without which a circuit would not be possible in the case of cleaning, because the metering tube is completely open on the output side at the bottom.

Because systems such as this known dosing system have to be cleaned from time to time, there was a desire for improvements in the conversion work from dosing operation to cleaning operation and in particular avoiding long-term downtimes of the entire machine.

The invention has for its object to improve a system for filling packs of the type mentioned in such a way that the machine can be cleaned better without extensive disassembly work and the filling operation can be started again after a short changeover.

This object is achieved in that the filling pipe is provided in the immediate vicinity of its outlet with the pressure relief valve and has the inside of the piston and the piston rod, that the feed line is arranged in the line from the flow tank to the filling pipe below the flow tank and that the piston on the edge is so flexible that during the return stroke it moves through the supply of the filling material above. These features of the new filling system ensure a complete maintenance of the function, although the system can be subjected to a total cleaning without having to dismantle larger parts of the system when converting from filling operation to cleaning operation and then reassembling; and that while maintaining a simple structure of the new system. The piston is equipped with high flexibility at the edge, so that it moves through the supply of the filling material on the return stroke. This results in a compact design and reliable function.

A problem with filling unilaterally open packages that are conveyed out of a package manufacturing machine with liquids is the exact dosing or filling without gas inclusions, air bubbles or foam (forms in milk). The flow tank mentioned is arranged in the vertical direction at the top and connected to the feed line arranged below it, so that all gases or trapped gases arising in this system or in other line parts which are connected to the feed line can rise upwards. In this case, the filling material can advantageously be fed into the supply tank, so that a larger liquid column is always arranged above the outlet side of the filling pipe arranged underneath, which is very suitable for receiving the gases rising upwards. As a result, the function of known filling systems can be fully maintained and, at the same time, better cleaning is provided, in particular because the flow container is connected to a supply line for cleaning agents with a simple construction. In the cleaning phase described below, the cleaning agent can therefore be introduced on one side of the system and removed on another side without essential parts of the system having to be dismantled and without this resulting in longer downtimes than are necessary for the cleaning process itself.

Furthermore, a shut-off valve is arranged in the line to the filling pipe, so that the operation can be divided into separate sections, not only the separation between the filling phase and the cleaning phase on the one hand but also the separation of individual stages within the cleaning phase on the other hand being possible. In other words, during the cleaning phase Actuation of these shut-off valves first the one part and then possibly later the second part to be cleaned. The shut-off valves at this point also favor maintenance or repair work, if this is necessary.

Finally, there is a spring in the pressure relief valve. The latter is arranged at the outlet end of the filling pipe, as was already customary in known filling pipes. The spring ensures that this pressure relief valve is closed until the filling pressure above this valve exceeds a certain value, after which the pressure relief valve opens. This also determines its name. This results in operational simplifications insofar as such overpressure is easily generated by the piston in the filling tube, preferably whenever a certain dose of filling material is to be ejected. This pressure relief valve always opens for the discharge and then closes again. The arrangement of a pressure relief valve that closes in this way at the outlet end of the filling pipe is particularly expedient when liquid filling material is to be processed and, by means of measures taken consciously, during the return stroke of the piston to the inlet end of the filling pipe and into the room via the pressure relief valve , which is the part of the filling pipe on the outlet side.

The above-mentioned measures and solution features thus allow the creation of a filling system in which liquids can be conveyed perfectly despite the risk of gas inclusions or foam formation and can be filled into packs in predetermined doses, after which cleaning is easily possible.

It is also advantageous according to the invention if an inlet valve is connected to the inlet-side end of the feed line and can be controlled by a probe arranged on the inlet vessel for sensing the filling level in the inlet vessel. There are probes commercially available that can be attached to containers are that they switch to a first state when a certain fill level of the contents is reached or exceeded, in which, for example, the inlet valve on the feed line is closed and, when this fill level is reached or fallen below, specify a different, second switching state or a corresponding control signal, so that the inlet valve is then opened, for example. In this way, you can always keep the flow tank filled at a desired level, so that the feed pipe and thus also the pressure relief valve in the filling pipe always have approximately the same height of the filling material or, in the case of liquids, the height of the liquid column.

It is also expedient according to the invention if the supply line for cleaning agents opens tangentially into the peripheral wall of the flow container and its upper part. It was already stated above that the aim of the invention is not only to construct the system in a particularly simple manner but also to ensure cleaning without major assembly work. Such cleaning is favorable on the one hand if it is possible to run the system from one end to the other. This is the case here according to the invention in that one end of the system represents the upper part of the flow container. It is precisely in this part at the top of the supply tank that the cleaning agent feed line opens. It will be further explained that the cleaning agent can flow off at the other end, and this other end is preferably the outlet side of the filling pipe, where the pressure relief valve is arranged in normal operation. However, the cleaning is particularly thorough and without manual intervention by the personnel if the supply line for cleaning agents is arranged tangentially in the peripheral wall, so that the cleaning agent introduced creates a vortex solely through the inlet, which guarantees a perfect cleaning of the supply container, even without after Disassembly of its lid cleaning tools would have to be introduced, such as Brushes, rags or scrapers.

The invention is further advantageously designed that the flow tank is provided at the top with a vent valve, preferably having a filter. Although gases that settle at the top of the flow tank could be removed by opening the inlet valve for cleaning agents, it has proven to be more expedient to keep this inlet valve closed in normal filling operation and instead to install the aforementioned vent valve at the top of the system. A filter is preferably arranged on the vent valve, which can expediently prevent the entry of bacteria from the environment into the flow container from the outside inwards.

According to the invention, the feed line for the filling material is also advantageously connected to a series of shut-off valves, each with a downstream filling pipe. This measure allows the simultaneous filling of several packs, that is, the filling in series. This type of filling is particularly desirable in high-performance machines if packs are produced in such a way that two, four, six or at least several packs in a row have to be filled in succession at the same time. In this case, the output of a filling system is multiplied accordingly. With an appropriate design of the diameter of the feed line for filling material, a number of filling pipes can also be supplied with filling material without the fluctuations in the supply tank causing problems. The larger the number of filling pipes, the larger the diameter of the feed line for the filling material and preferably also of the flow container will be selected.

In a further embodiment of the invention, the inlet-side part of the filling pipe has a larger diameter than its outlet-side part, and the piston, which is designed as a sleeve with a flexible rim, is provided in the inlet-side part. A suitable size distribution between the inlet-side and the outlet-side part of a filling tube allows the quantity of filling material to be metered out to be precisely adjusted and maintained. The arrangement of the piston in the inlet-side part with the larger diameter allows even smaller ones Hubs larger volumes to be filled. It is also essential for the invention that the piston is designed as a sleeve, that is to say it is flexible at the edge. The man skilled in the art already knows similarly simple cuffs from other pumps, for example also with bicycle air pumps. It has been shown that when the measures according to the invention mentioned here are used, the use of a simple cuff as a piston also guarantees the precise filling operation, although the quantities of filling material which have been dispensed can still be adhered to exactly. The advantage of simplifying and making the system more economical is obvious.

It is also expedient according to the invention if the piston rod is arranged in the inlet-side part of the filling tube and is mounted on the end wall of the filling tube arranged on the inlet side by means of a separate insert. Inside such an insert is a space that acts as a vapor barrier during operation, so that no gases escape from the contents nor - what is more important when filling liquid foods - contamination from the environment and air from the outside of the contents can be done. The piston rod is expediently stored at two spaced ends of this separate insert, between which the chamber with the vapor barrier effect is arranged. The distance between the two bearing points of this insert, which are preferably designed as slide bearings, must then be greater than the stroke of the piston.

In the inlet-side part of the filling pipe with a larger diameter, the piston, which is preferably designed as a simple sleeve, can be moved back and forth with the aid of the piston rod. In the case of filling pipes that are already working in test facilities, these are arranged in the plumb line. The piston oscillates in the vertical direction. This movement can be controlled by motors with link guides or by air rotating cylinders, which are known per se to the person skilled in the art. It can be important to change the stroke of the piston without much To have to make modifications. Such drives are also commercially available.

Figur 1

schematisiert eine teilweise im Schnitt genommene Seitenansicht einer Befüllungsanlage mit Vorlaufbehälter, Speiseleitung und Füllrohr und mit Antriebsmöglichkeiten für die Bewegung der Kolbenstange und

Figur 2

eine andere Seitenansicht der Befüllungsanlage mit Teilen der Packungsherstellungsmaschine.

Further advantages, advantageous features and possible uses of the present invention result from the following description of a preferred exemplary embodiment in conjunction with the attached drawings. Show it:

Figure 1

schematized a partially sectioned side view of a filling system with a flow tank, feed line and filling pipe and with drive options for the movement of the piston rod and

Figure 2

another side view of the filling system with parts of the packaging machine.

For a general understanding of the filling system, FIG. 2 is first described, which overall shows a production machine for packs 1 of paper coated on both sides with plastic. The package is tubular, for example with an essentially round or square cross section, the bottom of the package being formed by folding the paper and the cover being formed by injection molding a thermoplastic.

The role of the plastic-coated paper web from which the tube is formed is not shown. This is also produced four times in a manner not shown in the machine of FIG. 2 and pushed onto the mandrels 2 by mandrel wheels, which are rotated intermittently driven about the common axis 3. After pushing the tube open on both sides onto a mandrel 2, which in this state lies behind the respective mandrel wheel in the direction perpendicular to the plane of the paper, the mandrel wheel is advanced by 90 ° in such a way that a mandrel 2 that has just been viewed is moved to the upper position in FIG. 2 reached. For this purpose, it is assumed that the respective two pivot levers 4 are pivoted apart about the axes 5 'lying in the direction perpendicular to the paper plane of FIG. 2 so that the space for turning the mandrel in 2 is free. The mandrel represents the inner shape of an injection mold, the swivel levers having suitably designed inner surfaces, so that in the retracted state, as shown in FIG. 2, the outer shaped part is formed by the two swivel levers 4. In the mold cavity formed by the outer molded part, ie the two pivot levers 4 on the one hand and the mandrel 2 from the inside, plastic is introduced from the respective injection unit 5, which is supplied with plastic via the dashed lines 6, to inject a cover onto one end of the tube . In the container 7, the plastic is still in the form of granules. Four injection units 5 are held side by side in the carrier 8 of the machine, drive wheels 9 and levers 10 being shown schematically at the upper end of the injection units, which are not discussed in detail here, since the injection process and the machine for this are described in more detail elsewhere.

The mandrel 2 with the molded-on cover finally reaches the lower position in FIG. 2 below the common axis 3 and is conveyed into the position of the long row of packs 1 by a stripper (not shown). In this row the lid is located on the tube at the bottom, and the material area of the tube at the top, from which the bottom is later made by folding, is still unfolded so high that the package 1 is open at the top. From these positions, the respective pack is conveyed in the direction of arrow 11 under the filling system, generally designated 12. Devices, not shown, ensure, for example, the simultaneous lifting of four packs arranged exactly in register with the filling pipes 13 for gripping around the outlet-side part 14 of the filling pipe 13, whereby after the filling of these devices, the lowering to the level of the horizontal conveyor is again ensured. Further in the direction of arrow 11, the packs which are still open at the top but are now filled are conveyed under the sealing station 15, then turned at the right end by 90 °, brought into an upper conveyor 16 which moves in the direction of the arrow 17. Here, the packs are provided by a cam device 18 with the bottom shape that is ultimately desired provided, that protruding triangular flaps are folded, pressed and welded, so that finally a filled and closed on both sides, tubular package can be conveyed via a conveyor 19.

The above explanation of the manufacturing and filling machine for liquid packs makes it understandable that the filling system 12 acts as a part and operates in a synchronously driven manner. The filling system 12 essentially has a horizontally arranged feed line 20, at the inlet-side end of which an actuable inlet valve 21 and at the opposite end of a feed tank 22 with a ventilation valve 23 arranged at the top is arranged. The filter in the vent valve 23 is not shown.

From Figure 1 it can be seen how a shut-off valve 25 is connected under the flow container 22 in the connected line 24, which leads to the filling pipe 13. The air cylinder 26 arranged to the left of it is provided for driving it.

If one looks at FIG. 2, one looks, so to speak, in the representation of FIG. 1 from right to left, so that one sees the different filling tubes 13 next to one another. The shut-off valves 25 connected under the feed line 20 are assigned to each filling pipe 13.

The respective filler tube 13 consists of an inlet-side part 27 with a larger diameter d 1 and an outlet-side part 14 arranged below it with a smaller diameter d 2. The transition between these two parts 14 and 27 takes place through a truncated cone-shaped jacket 28.

A piston 29 in the form of a simple sleeve is located approximately in the middle of the inlet-side part 27 with the larger diameter d 1 and can from the piston rod 30 to dispense a certain amount of filling material in the direction of arrow 31 around the stroke h in the inlet-side part 27 the larger diameter d 1 are moved down. After that he will pulled back into the upper position.

On the lower, outlet-side part 14 of the filling tube 13 there is a pressure relief valve 32, the spring 33 of which ensures its closed position with such a force that this valve 32 only opens at a pressure of greater than 0.2 bar. Only at this overpressure is the force of the spring 33 overcome, so that the valve 32 opens. This value of 0.2 bar, which can of course be set to other values in other systems, arises from the liquid column in the filler pipe 13 up to the liquid level 34 in the supply tank 22. The pressure relief valve 32 is also provided with a cover 35, which can be seen in FIG 2 recognized.

On the inlet-side part 27 of the filling tube 13, an end wall 36 with a fastening connection 37 is attached on the inlet side at the top, in which a separate insert 38 made of elastic material is arranged. This insert 38 is hollow and defines an inner chamber 39 which acts as a vapor barrier during operation in order to avoid contamination of the liquid foodstuffs by outside air. The insert 38 has a length d₃, which is greater than the stroke h, so that when the piston 29 moves with its piston rod 30 via the stroke h, no part of the piston rod comes out of the interior of the filling tube 13 via the insert 38 upwards. This means that the environment or outside air cannot contaminate any parts of the piston rod 30 which subsequently enter the filling tube 13.

At the upper end of the piston rod 30 on the drive side, a tab 40 is rotatably articulated, on the upper side 41 of which an articulation point is eccentrically attached to an air cylinder 42. This cylinder 42 preferably rotates 180 ° first in one direction and then in the other direction, so that during operation the piston rod 30 continuously makes an oscillating movement.

A dashed line is at the top right next to the air rotating cylinder 42 another drive option indicated, namely with a motor 43 and pin 44 which is displaceable in a link guide 45 of a lever 46, whereby this lever 46 is rotatable about the stationary bearing 47 and can be moved up and down in the direction of the double arrow 48 so that in turn a Similar tab as the tab 40 would cause an oscillating up and down movement of the piston rod 30 when attached to this lever 46.

The difference between the two types of drive is that the articulation point 41 of the bracket 40 is more difficult to adjust in the case of the pneumatic cylinder 42 (if other strokes are to be set) than in the right-hand dashed illustration. There a displacement of the motor 43 in the direction of the arrow 49 on the right or left is sufficient to make the stroke smaller or larger.

A feed line 50 for cleaning agent opens tangentially at the flow tank 22 and can be shut off via an inlet valve 51.

The inlet valve 21 is controlled by a probe, not shown, which opens the inlet valve 21 when the liquid level 38 falls below a certain level; and closes when the liquid level 34 rises above the previously set mark.

The normal filling is carried out in such a way that the inlet valve 21 is opened and the filling material enters the feed line 20 in the direction of the arrow 52. After filling the feed line 20, the liquid to be filled slowly rises to the fill level 34 in the flow tank 22. If the shut-off valves 25 are opened, the fill pipes 13 also fill. The vent valve 23 is open during operation. Any air that is trapped in the system escapes up into the feed tank 22 and from there through the vent valve 23 into the atmosphere.

The piston 29 determines the output quantity via its stroke h. These a simple cuff does not require any elaborate guidance since the outer edge of the cuff, ie the piston 29, is very flexible and is also permissible for operation. When filling material is ejected by the movement of the piston 29 in the direction of the arrow 31 by the stroke h downward, an overpressure arises in front of the piston 29 (below the same in the drawing), by means of which the flexible edge of the piston 29 firmly adheres to the wall of the filling tube 13 is pressed, the force of the spring 33 is overcome, the pressure relief valve 32 opens, and the pack 1 is filled. During the ejection of the filling material, a negative pressure is created in the space above the piston 29. Because the valve 25 is open, contents can be sucked in from the feed line 20 or else from line 24. The piston 29 then moves back into the position shown in FIG. 1. Before the return stroke, ie in the lower end position of the piston 29, the valve 25 is closed by a signal. There is no longer any pressure difference in the filling tube 13. During the return stroke of the piston 29 upwards, the liquid flows over the side at the edge of the cuff, so that the space above the pressure relief valve 32 fills again under the piston 29. The piston 29 practically moves through the supply of the filling material. As a result, the volume emptied by the discharge is replenished under the piston 29. The liquid collecting in the outlet-side part 14 of the filling pipe 13 is blocked by the pressure relief valve 32, because this is closed. As stated, the opening takes place only by the downward movement of the piston 29 in the direction of the arrow 31.

The operation of cleaning will now be described after the filling process is completed. It is assumed that the feed line 20 is empty. The inlet valve 21 is closed. Instead, the feed valve 51 is opened for cleaning liquid, which then enters tangentially through the line 53 into the feed line 50 and into the feed tank 22. Here there is a swirl with a good cleaning effect. Furthermore, the cleaning fluid then flows down into the feed line 20 and fills the line 24 to the shut-off valves 25, which are initially assumed to be closed in this first phase. The filling tubes 13 are initially regarded as empty, so that in the first cleaning phase only the upper line is first completely cleaned.

After this has been done, the shut-off valves 25 are opened, and at the latest now the inlet valve 21 must be closed. The cleaning liquid now flows down into the filling tubes 13, via the piston 29, past the sleeve downwards into the outlet-side part 14 of the filling tube 13. Incidentally, during the cleaning, the pistons 29 work by performing their oscillating up and down movement.

The only and less complex assembly for the cleaning operation is that the pressure relief valve 32, as has also been the case in known devices up to now, is removed by hand, cleaned and reinstalled later. During the second cleaning phase of the filling pipes 13, the outlet-side ends of the filling pipes 13 are connected together to a return pipe via lines (not shown). The cleaning liquid therefore flows down through the filling pipes 13 and back into the feed system (not shown) via the return pipes.

Claims (7)

1. A machine for filling packages (1) with flowable contents, having a piston (29) and a piston rod (30), wherein a fill pipe (13) arranged substantially vertically and provided with a closable relief pressure valve (32) which is prestressed by a spring (33) is supplied at the intake side via a feed conduit (20), having a lead container (22) which is connected to a supply conduit (50) for cleaning agent, and having a check valve (25) which is arranged in the conduit (24) extending from the lead container (22) to the fill pipe (13), characterised in that the fill pipe (13) is provided in the immediate vicinity of its outlet with the pressure relief valve (32) and on the inside has the piston (29) and the piston rod (30), that the feed conduit (20) is arranged in the conduit (24) from the lead container (22) to the fill pipe (13) under the lead container (22), and that the piston (29) is flexible at the edge in such a way that with the return stroke it moves through the supply of contents to be filled which are disposed above it.
2. A machine according to Claim 1, characterised in that an intake valve (21) is attached at the intake end of the feed conduit (20), the intake valve being controllable by a probe arranged on the lead container (22) for detecting the fill level (34) in the lead container (22) (Figure 2).
3. A machine according to Claim 1 or Claim 2, characterised in that the supply conduit (50) for cleaning agent opens tangentially into the upper part of the peripheral wall of the lead container (22).
4. A machine according to Claim 1 or 3, characterised in that the lead container (22) is provided at the top with a relief valve (23) which preferably has a filter.
5. A machine according to one of Claims 1 to 4, characterised in that the feed conduit (20) for contents to be filled is connected to a series of check valves (25) each having a respective fill pipe (13) arranged downstream thereof (Figure 2).
6. A machine according to one of Claims 1 to 5, characterised in that the inlet side part (27) of the fill pipe (13) is greater in diameter (d₁) than its outlet side part (14) (d₂), and that the piston (29) which is preferably in the form of a collar is provided in the intake side part (27) (Figure 1).
7. A machine according to one of Claims 1 to 6, characterised in that the piston rod (30) is arranged in the intake part (27) of the fill pipe (13) and is mounted to the end wall (36), arranged at the intake side, of the fill pipe (13) by means of a separate insert (38) (Figure 1).

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