DE102021104860A1 - Process and device for preparing preforms - Google Patents

Abstract

The invention relates to a method for providing and feeding preforms to a device for the production of containers by reshaping the preforms by applying pressure with a fluid, comprising: a) placing the preforms in a filling container (18) in a transfer device (19) for transfer of the preforms into a storage container (12), b) monitoring a filling level (29) in the storage container (12), c) automatic emptying of the filling container (18) into the storage container (12) when the filling level (29) in the storage container (12) falls below a first limit value (31),d) removal of the preforms from the storage container (12) in a conveying flow,According to the invention, a second limit value (32) of the fill level (29) is monitored at the storage container (12), the second Limit value (32) is greater than or equal to the first limit value (31), that the filling container (18) has a filling condition (30) that is determined, and that when it falls below the second Limit value (32) in the storage container (12) the filling state (30) in the filling container (18) is evaluated in order to control filling of the filling container (18) or replacement of the same by a filled filling container (18). The invention also relates to devices for Providing preforms for a device for producing containers by forming the preforms by means of pressurization with a fluid, these devices operating according to the method described.

Description

The invention relates to a method for providing and feeding preforms according to the preamble of claim 1. The invention also relates to a device according to the preamble of claim 14, in particular for carrying out the method.

Plastic containers are produced by forming preforms by means of pressurization with a fluid, ie pneumatically or hydraulically, in particular in a blow molding process or stretch blow molding process or in the so-called form-fill process. In particular, the containers are made of PET, preferably bottles.

The preforms are kept ready as bulk material in a storage container and removed from this in a conveying flow. The conveying flow leads to a heating device in which the preforms are thermally conditioned. From the heating device, the preforms are transferred to a device with blow molds with the aid of a transfer conveyor.

An unintentional interruption of the flow from the reservoir should be avoided. The content or fill level of the reservoir is therefore monitored. As soon as the value falls below a first limit value, preforms are automatically transferred from a filling container to the storage container. The filling container is then immediately refilled or replaced by a filled one. This means that each time the preforms are transferred from the filling container to the storage container, the filling container is also refilled or replaced.

The object of the present invention is to create a method with which the overall effort involved can be reduced.

1. a) Platzieren der Vorformlinge in einem Füllbehälter in einer Umfüllvorrichtung zum Umfüllen der Vorformlinge in einen Vorratsbehälter,
2. b) Überwachen eines Füllstands im Vorratsbehälter,
3. c) automatisches Entleeren des Füllbehälters in den Vorratsbehälter, wenn der Füllstand im Vorratsbehälter einen ersten Grenzwert unterschreitet,
4. d) Entnahme der Vorformlinge aus dem Vorratsbehälter in einem Förderstrom,

umfassenden Ablauf, ist insbesondere vorgesehen, dass am Vorratsbehälter ein zweiter Grenzwert des Füllstands überwacht wird, wobei der zweite Grenzwert größer oder gleich dem ersten Grenzwert ist, dass am Füllbehälter ein Befüllungszustand bestimmt wird und dass bei Unterschreiten des zweiten Grenzwerts im Vorratsbehälter der Befüllungszustand im Füllbehälter ausgewertet wird, um eine Befüllung des Füllbehälters oder einen Ersatz desselben durch einen befüllten Füllbehälter zu steuern. Demnach wird der zweite Grenzwert vor dem ersten Grenzwert zusätzlich berücksichtigt. Dadurch können die Befüllung oder der Austausch des Füllbehälters noch besser und vorausschauender geplant und durchgeführt werden. Das erfindungsgemäße Verfahren wird vorzugsweise für die Herstellung von Behältern in einem Blasprozess oder im Form-Fill-Verfahren verwendet, jeweils mit oder ohne Reckstange.To solve the problem, the method according to the invention has the features of claim 1. Starting from a the steps

1. a) placing the preforms in a filling container in a transfer device for transferring the preforms into a storage container,
2. b) monitoring a fill level in the reservoir,
3. c) automatic emptying of the filling container into the storage container when the filling level in the storage container falls below a first limit value,
4. d) removal of the preforms from the storage container in one flow,

comprehensive process, it is provided in particular that a second limit value of the fill level is monitored on the storage container, with the second limit value being greater than or equal to the first limit value, that a filling status is determined on the filling container and that if the second limit value in the storage container is undershot, the filling status in the filling container is evaluated in order to control a filling of the filling container or a replacement of the same by a filled filling container. Accordingly, the second limit value is additionally taken into account before the first limit value. As a result, the filling or replacement of the filling container can be planned and carried out even better and with more foresight. The method according to the invention is preferably used for the production of containers in a blow molding process or in the form-fill method, in each case with or without a stretch rod.

• - bei Unterschreiten des zweiten Grenzwerts im Vorratsbehälter und zugleich leerem Füllbehälter der Füllbehälter gefüllt wird oder durch einen gefüllten Füllbehälter ersetzt wird,
• - der gefüllte Füllbehälter automatisch in den Vorratsbehälter entleert wird,
• - und der nun wieder leere Füllbehälter gefüllt oder durch einen gefüllten Füllbehälter ersetzt wird, ohne das Unterschreiten eines der Grenzwerte des Füllstands abzuwarten.

According to a further idea of the invention, it can be provided that

• - if the second limit value in the reservoir is not reached and the filling container is empty at the same time, the filling container is filled or replaced by a filled filling container,
• - the filled filling container is automatically emptied into the storage container,
• - And the filling container, which is now empty again, is filled or replaced by a filled filling container, without waiting for the filling level to fall below one of the limit values.

Thus, the filling container is only refilled when the storage container is almost empty again, namely when its fill level falls below the second limit value. In this way, the effort to fill the filling container can be almost halved. A complete halving of the effort is not possible, since the filling container and the storage container cannot be filled in an arbitrarily short time and the preforms are continuously conveyed away from the storage container.

1. a) der Füllstand im Vorratsbehälter den zweiten Grenzwert unterschreitet und zugleich der Füllbehälter leer ist, oder
2. b) das Füllen oder Ersetzen des zuvor automatisch in den Vorratsbehälter entleerten Füllbehälters nicht innerhalb einer definierten Zeitspanne erfolgt.

According to a further idea of the invention, a signal can be generated at least when

1. a) the filling level in the storage container falls below the second limit value and at the same time the filling container is empty, or
2. b) the filling or replacement of the filling container previously automatically emptied into the storage container does not take place within a defined period of time.

The signal according to a) signals to the operator that it is necessary to refill the filling container. The decanting from the filling container into the reservoir takes place automatically by a corresponding decanting device when the fill level in the reservoir falls below the first limit value.

The signal according to b) ensures that the previously emptied filling container is filled again. The period of time also depends on the speed of movement of the hopper and the time required to fill or change the hopper and is preferably between one and five minutes.

Of course, the signal can also be provided for both cases a) and b).

According to a further idea of the invention, the signal can be an optical and/or acoustic signal. The signal is preferably output by a buzzer, a horn, a loudspeaker, a lamp or a signal lamp. According to the invention, an indication on a display is also an optical signal.

According to a further idea of the invention, it can be provided that the filling container is used as a transport container and the filled transport container is fed to the decanting device and emptied transport containers are removed. The filling container thus has a dual function. Alternatively, the filling container is installed at the site of the decanting device or is part of the decanting device and is filled cyclically.

According to a further idea of the invention, the fill level in the storage container can be determined by one or more light barrier measurements on the storage container. This is a well-known and established technique for determining the filling level.

According to a further idea of the invention, the limit values can be monitored using optical sensors. Optical sensors are proven, easy to use and control. In particular, these are cameras, infrared sensors, light barriers.

According to a further idea of the invention, the optical sensors can monitor at least two linear areas in the reservoir, with the areas lying one above the other at a distance and, in particular, running transversely to one another. The linear areas preferably run approximately in the middle or within a middle third of the storage container, based on the length and width of the storage container. One of the linear areas advantageously extends parallel to the conveying direction of a discharge conveyor, which is arranged under the storage container.

According to a further idea of the invention, the filling level in the storage container can be determined by measuring the weight on the storage container. By determining the weight of the storage container, the fill level can be determined relatively accurately, since the preforms are designed with the same mass.

According to a further idea of the invention, a distinction should only be made between "full" and "empty" for the filling state of the filling container. This simplifies the control of the process. The filling status can be stored in a control unit and used to control the process.

According to a further idea of the invention, a filling state “full” can be determined for the filling container by establishing or detecting insertion of the filling container into the decanting device. It is not the content of the filling container that is detected, but rather its presence in the decanting device. This also simplifies the process. "Full" can be noted in the control unit until another filling status is detected.

• - ein Kippvorgang des Füllbehälters,
• - ein Verlassen einer Ausgangsstellung des Füllbehälters,
• - eine Bewegung des Füllbehälters aus der Ausgangsstellung in eine Übergabestellung,
• - ein Erreichen der Übergabestellung,
• - ein Verlassen der Übergabestellung,
• - eine Rückbewegung in die Ausgangsstellung oder
• - ein Erreichen der Ausgangsstellung

festgestellt oder detektiert werden. Der Füllbehälter ist zwischen Ausgangsstellung und Übergabestellung bewegbar. In der Übergabestellung fallen die Vorformlinge in den Vorratsbehälter, in der Ausgangsstellung ist der Füllbehälter in Bereitschaft und die Vorformlinge können nicht in den Vorratsbehälter fallen. Der Befüllungszustand „leer“ wird angenommen, sobald eine oder mehrere der genannten Bedingungen erfüllt sind, insbesondere sofern bisher der Befüllungszustand „voll“ galt oder in der Steuerung vorlag.According to a further idea of the invention, a filling status “empty” can be determined for the filling container by

• - a tipping process of the filling container,
• - Leaving a starting position of the filling container,
• - a movement of the filling container from the initial position into a transfer position,
• - reaching the transfer position,
• - leaving the transfer position,
• - a return movement to the starting position or
• - reaching the starting position

be established or detected. The filling container can be moved between the initial position and the transfer position. In the transfer position, the preforms fall into the storage container, in the starting position the filling container is ready and the preforms cannot fall into the storage container. The filling status "empty" is assumed as soon as one or more of the conditions mentioned are met, in particular if the filling status "full" previously applied or was present in the controller.

The invention also relates to a method according to claim 13, namely for producing containers by providing preforms, feeding the preforms in a conveying stream, thermal conditioning of the preforms and subsequent forming by means of pressurization with a fluid, in particular to form containers in a blow molding process or stretch blow molding process or in the form-fill process. According to the invention, the method described above for preparing and feeding the preforms is used.

1. a) einen Vorratsbehälter, aus dem die Vorformlinge in einem Förderstrom entnehmbar sind,
2. b) eine erste Überwachungseinrichtung zum Überwachen eines Füllstands an Vorformlingen in Vorratsbehältern,
3. c) einen Füllbehälter, in dem die Vorformlinge platziert werden,
4. d) eine Umfüllvorrichtung zum automatischen Umfüllen der Vorformlinge aus dem Füllbehälter in den Vorratsbehälter in Abhängigkeit von einem ersten Grenzwert des Füllstands im Vorratsbehälter.

The subject matter of the invention is also a device according to claim 14. The device is provided for preparing preforms for a device for producing containers by shaping the preforms by means of pressurization with a fluid, in particular in a blow molding process or stretch blow molding process or in the form-fill process, and includes in particular:

1. a) a storage container from which the preforms can be removed in one flow,
2. b) a first monitoring device for monitoring a filling level of preforms in storage containers,
3. c) a filling container in which the preforms are placed,
4. d) a decanting device for automatically decanting the preforms from the filling container into the storage container as a function of a first limit value of the fill level in the storage container.

According to the invention, the device has in particular a second monitoring device for determining the filling status in the filling container. The method according to the invention can be carried out advantageously with the device, also in accordance with all the features of the embodiments of the method subclaims. The second monitoring device ensures that the filling status of the filling container can preferably be determined qualitatively or even recorded quantitatively. The second monitoring device can also be integrated into a controller, in particular into a control device.

According to a further idea of the invention, the first monitoring device can be provided for monitoring the first limit value and a second limit value of the filling level in the reservoir. The monitoring of two limit values enables predictive process control.

1. a) der Füllstand im Vorratsbehälter den zweiten Grenzwert unterschreitet und zugleich der Füllbehälter leer ist, oder
2. b) das Füllen oder Ersetzen zuvor des automatisch in den Vorratsbehälter entleerten Füllbehälters nicht innerhalb einer definierten Zeitspanne erfolgt.

According to a further idea of the invention, a signaling device can be provided with which a signal can be output at least when

1. a) the filling level in the storage container falls below the second limit value and at the same time the filling container is empty, or
2. b) the previously automatically emptied filling container into the storage container is not filled or replaced within a defined period of time.

The signaling device emits a signal in one of the cases a), b) or in both cases. The signaling device can be controlled by a correspondingly set up control device.

According to a further idea of the invention, the signaling device can emit an optical and/or acoustic signal. The specific design of the signaling device should depend on the environmental conditions at the location of the device and on the work processes envisaged. The optical signal can also be shown on a display.

According to a further idea of the invention, it can be provided that the first monitoring device contains at least one optical sensor. In particular, it is a light barrier. An optical sensor within the meaning of the invention is also a camera with image processing.

According to a further idea of the invention, the monitoring device can have a first sensor for monitoring the first limit value and a second sensor for monitoring the second limit value. By dividing them into two sensors, they can be designed more simply.

According to a further idea of the invention, the in particular optical sensors can monitor at least a first line-shaped area for the first limit value and a second line-shaped area for the second limit value.

According to a further idea of the invention, the two linear areas can run transversely to one another. The line-shaped areas preferably extend in a horizontal plane.

According to a further idea of the invention, the first linear area can run in the direction of the conveying flow, in particular parallel to it. The conveying flow is the amount of preforms on a discharge conveyor arranged below the storage container. The preforms fall from a gap onto the discharge conveyor, with the gap preferably extending on an underside of the storage container and in particular over its length.

According to a further idea of the invention, the first monitoring device can contain at least one sensor for determining a weight of the storage container. Determining the weight allows relatively precise conclusions to be drawn about the number of preforms still in the storage container.

According to a further idea of the invention, an optical sensor can be provided to determine the filling level in the filling container. Here, too, it is preferably a light barrier or a camera with image processing.

According to a further idea of the invention, a sensor for determining a weight of the filling container can be provided to determine the filling status in the filling container. The number of preforms in the filling container can also be determined relatively precisely in this way.

According to a further idea of the invention, the filling container can be provided and suitable as a transport container at the same time. This makes it possible to fill the filling container or transport container outside of the device and then to transport it to the location of the device for decanting.

According to a further idea of the invention, a controller can be provided, at least for evaluating the filling level in the storage container, the filling status in the filling container and for controlling the transfer device for automatically transferring the preforms from the filling container into the storage container. The controller detects or determines whether the filling container is full or empty, the filling level in the storage container falls below one of the limit values and controls the decanting device. The controller preferably also controls the signaling device.

The subject matter of the invention is also a system according to claim 28, namely with a device according to the invention. The latter is then part of a larger system in which the preforms are stored, separated, thermally conditioned and then formed into containers by applying pressure with a fluid, in particular in a blow molding process or stretch blow molding process or in the form-fill process.

The device and/or system are provided with an electronic control device which controls the transfer device, in particular one, several or all of the processes listed below: automatic emptying of the filling container into the storage container, monitoring the level in the storage container, determining the filling level in the filling container, below defined conditions drive a signaling device to output a signal. The control device is provided with suitable software for this purpose.

• 1 bis 8 Füllbehälter und Vorratsbehälter im Zeitablauf mit unterschiedlichen Positionen des Füllbehälters,
• 9 eine schematische Darstellung einer Anlage zum Herstellen von Behältern in der Draufsicht,
• 10 bis 15 einen aufrechten Schnitt durch den Vorratsbehälter mit im Zeitverlauf unterschiedlichen Füllständen.

Further features of the invention emerge from the rest of the description and from the claims. Advantageous exemplary embodiments of the invention are explained in more detail below with reference to drawings. Show it:

• 1 until 8th filling container and storage container over time with different positions of the filling container,
• 9 a schematic representation of a plant for manufacturing containers in plan view,
• 10 until 15 an upright section through the reservoir with different fill levels over time.

Reference is first made to 9 . A system 10 for producing plastic containers from preforms, namely in a blow molding process or stretch blow molding process, is shown schematically. The forming process takes place in molds held on the circumference of a revolving working wheel 11 . Arrows show the path of the preforms through plant 10. The description of blow molding and stretch blow molding processes is given without restricting the generality. In the same way, the processes and sequences described below could be implemented in methods and devices in which a liquid forming fluid is used.

The individual preforms are removed from a storage container 12 or conveyed away from it in a quasi-continuous conveying flow 13 . In the area of a subsequent separating unit 14 , the preforms are spaced at a defined distance and transferred to a temperature control device 15 . The latter is followed by a transfer conveyor 16 which feeds the preforms to the working wheel 11 . In the molds of the working wheel 11, the preforms are formed into containers by the blow molding process or stretch blow molding process and finally conveyed out of the area of the working wheel 11 by a removal conveyor 17 and transferred to a discharge conveyor (not shown). Such a system is, for example, in DE 10 2018 107 676 A1 shown (without reservoir).

• Im Vorratsbehälter 12 werden die Vorformlinge als Schüttgut bereitgehalten. Bei der Abförderung im Förderstrom 13 werden die Vorformlinge vorzugsweise ausgerichtet. Für den ungestörten Ablauf der Anlage ist der ununterbrochene Förderstrom 13 von Bedeutung. Um dies sicherzustellen, wird der Vorratsbehälter 12 zyklisch aus einem Füllbehälter 18 mittels einer Umfüllvorrichtung 19 befüllt. Während der Vorratsbehälter 12 stationär ist, kann der Füllbehälter 18 stationär in der Umfüllvorrichtung 19 angeordnet oder als Transportbehälter von der Umfüllvorrichtung 19 aufnehmbar sein.

The filling of the reservoir 12 is based on the 1 until 8th explained:

• In the reservoir 12, the preforms are kept ready as bulk material. At the portage tion in the conveying flow 13, the preforms are preferably aligned. The uninterrupted flow 13 is important for the smooth running of the system. In order to ensure this, the storage container 12 is cyclically filled from a filling container 18 by means of a decanting device 19 . While the storage container 12 is stationary, the filling container 18 can be arranged in a stationary manner in the decanting device 19 or can be received by the decanting device 19 as a transport container.

The reservoir 12 is equipped with a monitoring device 20 with which a fill level in the reservoir 12 can be determined. The monitoring device 20 is preferably an optical sensor or a light barrier, a camera with image processing or a scale for determining the weight of the storage container. It is important that the monitoring device 20 cannot only differentiate between “filled” and “empty”. Rather, what is required is the detection of different fill levels in order to compare them with one or more limit values.

In a similar way, a monitoring device 21 is provided on the transfer device 19, with which the content or the presence of the filling container 18 can be detected. However, a distinction between "Filled" and "Empty" or "Available" and "Not available" is sufficient here. The monitoring device 21 can preferably be a button, a light barrier _, a camera with image processing or a scale.

The decanting device 19 is controlled by an electronic control device 22, in particular as a function of the values determined in the monitoring devices 20, 21. In addition, the control unit 22 controls a signaling device 23 for outputting an optical or acoustic signal. Finally, the control device 22 can also be connected to conveyors of the delivery flow 13, for example for drive control or for detecting a condition. Furthermore, the control device 22 can also be provided for controlling the other components of the system 10 or can be connected to a central control device for this purpose.

In the 1 until 8th are electrical lines 24, 25, 26, 27, 28 between the control unit 22 and the said system components 13, 19, 20, 21, 23 are shown. Depending on the task of the plant part in question, information and/or instructions can be transmitted.

• Zum Zeitpunkt 1 gemäß 1 sind Vorratsbehälter 12 und Füllbehälter 18 mit Vorformlingen gefüllt, siehe Füllstand 29 und Befüllungszustand 30. Mit dem Förderstrom 13 werden die Vorformlinge quasi-kontinuierlich aus dem Vorratsbehälter 12 entnommen. Entsprechend verringert sich der Füllstand 29 kontinuierlich.

The following sequence results from proper operation of the system:

• At time 1 according to 1 If the storage container 12 and filling container 18 are filled with preforms, see filling level 29 and filling state 30. The preforms are removed from the storage container 12 quasi-continuously with the conveying flow 13. The fill level 29 decreases accordingly.

At time 2 according to 2 Most of the preforms are removed from the storage container 12, so that the fill level 29 has dropped to a first limit value 31. The filling container 18 is still full.

Due to the first limit value 31 being reached in the storage container 12, the control unit 22 controls the decanting device 19 to empty the filling container 18, so that the contents of the filling container 18 are emptied into the storage container 12 and the highest filling level 29 is briefly reached again, see point in time 3 according to 3 . The preforms are being removed from the storage container 12 at all times.

At time 4 according to 4 is the filling container 18 from the tilted transfer position according to 3 moves back to its upright starting position and remains empty until further notice, while the level 29 in the reservoir 12 drops. After the filling container 18 has been moved back into the starting position, or beforehand when the filling container 18 is being emptied, the control unit 22 receives a specific signal B from the monitoring device 21. The signal B is interpreted by the control unit 22 as "filling container empty" and is deleted in the control unit 22 any other signal still present.

At time 5 according to 5 the fill level 29 in the reservoir 12 has dropped to a second limit value 32 which is above the first limit value 31 here. The control unit 22 then controls the signaling device 23 to output a filling signal. The filling container 18 is then filled by the operating personnel or the empty filling container 18 is exchanged for a full filling container. After replacing the filling container 18 or after filling it, the control unit 22 receives a specific signal A from the monitoring device 21. The signal A is interpreted by the control unit 22 as "filling container full" and deletes any other signal that may still be present in the control unit 22.

A full filling container 18 is then available in the starting position, while the storage container 12 is almost empty, see point in time 6 according to FIG 6 with filling level 29, which here reaches the limit value 31 more by chance, but can also be below or above it.

So that the storage container 12 is not completely emptied, the filling container 18 is immediately emptied into the storage container 12 by means of the decanting device 19, see point in time 7 according to FIG 7 . The control unit 22 again receives the signal B "Filling container empty". The reservoir 12 briefly reaches its highest filling level 29, as shown in 1 and 3 .

Finally, the filling container 18 is refilled or exchanged for a full filling container, see point in time 8 according to FIG 8th . The control unit 22 again receives the signal A "filling container full". The reservoir 12 is still almost full and continues to empty.

In the further course, the phases of 2 until 8th run through again or several times.

The sequence of the phases from point in time 5 to point in time 8 is particularly important. These phases follow one another immediately and without waiting time. During these phases, the hopper 18 is filled twice or exchanged for a full hopper, although the hopper 18 is emptied into the reservoir 12 only once in the sequence of times 5 through 8. The other or, depending on the point of view, the first or second emptying takes place after time 2, namely after the fill level 29 in the storage container 12 has reached its first limit value 31.

With the method and the device shown, the effort involved in handling the filling container 18 can be reduced. At the very least, the pauses between handling the filling container 18 are lengthened significantly.

The two limit values 31, 32 can theoretically also match. Second limit value 32 is preferably above first limit value 31, so that there is a time buffer for filling up filling container 18, because after reaching second limit value 32 and before filling storage container 12, filling container 18 must first be filled up or replaced.

The function of the control unit 22 is important in this context. Once the second limit value 32 in the storage container 12 has been undershot, this recognizes the refilling and the replacement of the filling container 18, controls the emptying of the filling container 18 into the storage container 12 and expects the filling or replacement to take place as soon as possible of the filling container 18. As mentioned above, the filling status of the filling container 18 is monitored by the monitoring device 21. If the control device 22 determines that the filling container 18 has not been refilled or replaced within a short, defined period of time, a signal is output via the signaling device 23 . Such a short period of time is in the range of minutes, for example.

In other words: the storage container 12 is cyclically filled with preforms, while the preforms are continuously removed from the conveying flow 13 . In contrast, the filling container 18 is only emptied in one period and filled, emptied and filled again in another period. The cycles of filling the filling container 18 thus differ from the cycles of emptying the filling container 18 or filling the storage container 12.

The detection of the filling level 29 in the storage container 12 by weighing it also enables an exact determination of the preforms still to be filled in at the end of production. The number of containers that have been completely formed and released from the working wheel 11 is known in any case, because the machines used generally record this. As a rule, the number of preforms located in front of the working wheel 11, ie in the conveying stream 13 up to the transfer conveyor 16, and the number of preforms that may have been discharged are also known. From this it is possible to calculate the number of preforms still to be poured for a total required production volume of containers. Accordingly, the filling container 18 is only filled with the quantity of preforms that is still required.

Alternatively, only the amount of preforms that is still required is filled from the filling container 18 into the storage container 12 . This can be controlled by weighing the storage container 12 in conjunction with a signal or by automatically pivoting the filling container 18 back. For example, a visual traffic light display can be provided which indicates when the storage container 12 has reached the required filling level and further filling has not more should be done. Finally, the weighing of the storage container 12 can be replaced by a light barrier. The measurement is then only inaccurate.

Based on 10 until 15 An example of the method according to the invention is explained below with the representation of the fill level 29 in the reservoir 12 . The filling level 29 relates to the preforms present as filling material in the storage container 12 .

An upright section through the storage container 12 is shown. The latter is open at the top and has a gap on its underside that cannot be seen in this view, parallel to a discharge conveyor 33 arranged underneath, with which the filling material can be conveyed from right to left into a transfer area 34. There the preforms from the discharge conveyor 33 to the in the 10 until 15 conveyor 13 not shown passed.

A roof-shaped guide profile 35 is arranged inside the storage container 12 at a distance from the discharge conveyor 33 and extends from an end face 36 to the end face 37 on the transfer side. The guide profile 35 prevents the entire load of the preforms present in the storage container 12 from acting on the discharge conveyor 33 . The preforms can only slide onto the discharge conveyor 33 from a lateral direction, ie perpendicularly to the conveying direction 38 onto the discharge conveyor 33 .

while in the 1 until 8th the monitoring device 20 is shown rather abstractly, are in the 10 until 15 More concrete measures shown, namely a first light barrier 40 above the guide profile 35 and parallel to the conveying direction 38. The light barrier 40 defines a linear area 41 of the monitoring.

In addition, a second light barrier 42 is arranged above, at a distance from the first light barrier 40 and perpendicular to it. The second light barrier 42 defines a linear region 43 which extends perpendicularly to the image plane, ie runs approximately in the horizontal direction and therefore in the 10 until 15 is shown only as a point.

The two light barriers 40, 42 form in the embodiment of 10 until 15 the in the 1 until 8th shown monitoring device 20 or are at least part of the same. The two limit values 31, 32 for the filling level 29 are monitored with the two light barriers 40, 42, and the reaching of the two limit values 31, 32 is detected.

In 10 the reservoir 12 is half full, in 11 almost complete. The level 29 in 11 corresponds approximately 1 .

In the ongoing production process, the preforms gradually slide onto the discharge conveyor 33 and are conveyed away in the conveying direction 38 from right to left. As a result, the filling level 29 decreases asymmetrically, predominantly first on the right-hand side near the end face 36, see 12 . The fill level 29 drops below the level of the second light barrier 42.

At this point in time it is further assumed that the filling container 18 is full. The control unit 22 controls the decanting device 19 and the content of the filling container 18 is emptied into the storage container 12, so that the filling level 29 is set above the second light barrier 42, as in 13 recognizable and analogous to 3 . The filling container 18 remains empty, as in 4 shown.

In the further course, the filling level 29 in the reservoir 12 drops again below the second light barrier 42, see FIG 14 . The control unit 22 then controls the signaling device 23 and a signal is output there, see FIG 5 . An operator fills up the hopper 18 or exchanges the empty hopper 18 for a full hopper. At the same time, the filling level 29 continues to drop until it reaches or below the first light barrier 40, see FIG 15 and as well 6 .

The control unit 22 recognizes that the filling container 18 is full and controls the decanting device 19 . The filling container 18 is emptied into the reservoir 12, so that the level 29 according to 10 or even according to 11 adjusts The filling container 18 is then refilled or replaced by operating personnel. The control unit 22 again recognizes that the filling container 18 is full. If the filling level 29 falls below the second light barrier 42 again, the filling container 18 can be automatically emptied into the storage container 12 by the decanting device 19, without intervention by the operating personnel.

When filling the reservoir 12 in the transition from 15 to 10 and 11 It may also be useful or necessary to fill or replace the filling container 18 three times in total, depending on the capacity. After the first filling or replacement and emptying into the reservoir 12, the level 29 according to FIG 10 . After the second emptying or replacement and filling of the reservoir 12, the fill level 29 in 11 and with the third filling or replacement of the filling container 18, the latter is in waiting position for the intermediate filling corresponding to the transition from 12 to 13 .

Reference List

10

attachment

11

working wheel

12

reservoir

13

sponsor

14

separation unit

15

temperature control device

16

transfer conveyor

17

removal conveyor

18

filling container (transport container)

19

transfer device

20

Monitoring Device (Reservoir)

21

Monitoring device (filling container)

22

control unit

23

signaling device

24

signaling device

25

electrical line

26

electrical line

27

electrical line

28

electrical line

29

fill level of the reservoir

30

Filling status of filling container

31

first limit

32

second limit

33

conveyor

34

transfer area

35

leading profile

36

face

37

face

38

conveying direction

39

inclined ground

40

first light barrier

41

linear area

42

second light barrier

43

linear area

QUOTES INCLUDED IN DESCRIPTION

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

Patent Literature Cited

• DE 102018107676 A1 [0043]

Claims (28)

Method for providing and feeding preforms to a device for the production of containers by forming the preforms by means of pressurization with a fluid, comprising: a) placing the preforms in a filling container (18) in a transfer device (19) for transferring the preforms into a reservoir (12), b) monitoring a level (29) in the reservoir (12), c) automatic emptying of the filling container (18) into the reservoir (12) when the level (29) in the reservoir (12) exceeds a first limit value ( 31), d) removal of the preforms from the storage container (12) in a conveying flow, characterized in that a second limit value (32) of the fill level (29) is monitored at the storage container (12), the second limit value (32) being greater or is equal to the first limit value (31), that a filling state (30) is determined at the filling container (18), and that when the second limit value (32) in the reservoir is undershot container (12) the filling state (30) in the filling container (18) is evaluated in order to control a filling of the filling container (18) or a replacement of the same by a filled filling container (18). procedure after claim 1 , characterized in that when the second limit value (32) in the storage container (12) and at the same time empty filling container (18) is fallen below, the filling container (18) is filled or is replaced by a filled filling container (18), the filled filling container (18) automatically is emptied into the reservoir (12), and the filling container (18), which is now empty again, is filled or replaced by a filled filling container (18), without waiting for the filling level to fall below one of the limit values (31, 32). procedure after claim 1 or 2 , characterized in that a signal is generated at least when a) the filling level in the storage container (12) falls below the second limit value (32) and at the same time the filling container (18) is empty, or b) the filling or replacement of the automatically in the Reservoir (12) emptied filling container (18) does not take place within a defined period of time. procedure after claim 3 , characterized in that the signal is an optical or acoustic signal. Procedure according to one of Claims 1 until 4 , characterized in that the filling container (18) is used as a transport container and in that filled transport containers are fed to the decanting device (19) and emptied transport containers are removed. Procedure according to one of Claims 1 until 5 , characterized in that the filling level in the storage container (12) is determined by one or more light barrier measurements on the storage container (12). Procedure according to one of Claims 1 until 6 , characterized in that the limit values (31, 32) are monitored by optical sensors (40, 42). Procedure according to one of claim 7 , characterized in that the optical sensors (40, 42) monitor at least two linear areas (41, 43) in the reservoir (12), which are spaced one above the other and in particular run transversely to one another. Procedure according to one of Claims 1 until 5 , characterized in that the fill level in the storage container (12) is determined by measuring the weight of the storage container (12). Procedure according to one of Claims 1 until 9 , characterized in that for the filling state of the filling container (18) a distinction is made only between "full" and "empty". Procedure according to one of Claims 1 until 10 , characterized in that for the filling container (18) a filling state "full" is determined by inserting the filling container (18) into the decanting device (19) is established or detected. Procedure according to one of Claims 1 until 11 , characterized in that an "empty" filling state is determined for the filling container (18) in that - the filling container (18) is tilted, - the filling container (18) leaves an initial position, - the filling container (18) moves out of the starting position in a transfer position, - reaching the transfer position, - leaving the transfer position, - moving back into the starting position or - reaching the starting position can be determined or detected. Process for producing containers by providing preforms, feeding the preforms in a conveying stream, thermal conditioning of the preforms and subsequent forming into containers by means of pressurization with a fluid, characterized by a method for providing and feeding the preforms according to one of Claims 1 until 12 . Device for providing preforms for a device for manufacturing containers by shaping the preforms by means of pressurization with a fluid, comprising: a) a storage container (12) from which the preforms can be removed in a conveying flow, b) a first monitoring device (20) for monitoring a filling level (29) of preforms in the storage container (12), c) a filling container (18) in which the preforms are placed, d) a transfer device (19) for automatically transferring the preforms from the filling container (18) into the Reservoir (12) as a function of a first limit value (31) of the fill level (29) in the reservoir (12), characterized by a second monitoring device (21) for determining a filling status in the filling container (18). device after Claim 14 , characterized in that the first monitoring device (20) for monitoring the first limit value (31) and a second limit value (32) of the fill level (29) is provided. device after claim 15 , characterized by a signaling device (23) with which a signal can be output at least when a) the filling level (29) in the storage container (12) falls below the second limit value (32) and at the same time the filling container (18) is empty, or b ) the filling or replacement of the filling container (18), which is automatically emptied into the storage container (12), does not take place within a defined period of time. device after Claim 16 , characterized in that the signaling device (23) emits an optical or acoustic signal. Device according to one of Claims 14 until 17 , characterized in that the first monitoring device (20) includes at least one optical sensor. Device according to one of Claims 14 until 18 , characterized in that the monitoring device (20) has a first sensor (40) for monitoring the first limit value (31) and a second sensor (42) for monitoring the second limit value (32). device after claim 19 , characterized in that the in particular optical sensors (40, 42) monitor at least a first linear area (41) for the first limit value (31) and a second linear area (43) for the second limit value (32). device after claim 20 , characterized in that the two linear areas (41, 43) run transversely to one another. device after claim 20 or 21 , characterized in that the first linear area (41) runs in the direction (38) of the flow. Device according to claim one of Claims 14 until 22 , characterized in that the first monitoring device (20) includes at least one sensor for determining a weight of the storage container (12). Device according to one of Claims 14 until 23 , characterized in that an optical sensor is provided to determine the filling status in the filling container (18). Device according to one of Claims 14 until 23 , characterized in that a sensor for determining a weight of the filling container (18) is provided to determine the filling level in the filling container (18). Device according to one of Claims 14 until 25 , characterized in that the filling container (18) is also provided and suitable as a transport container. Device according to one of Claims 14 until 26 , characterized by a controller (22) at least for evaluating the filling level (29) in the storage container (12), the filling status (30) in the filling container (18) and for controlling the transfer device for automatically transferring the preforms from the filling container (18) into the reservoir (12). Plant (10) for producing containers by providing preforms, feeding the preforms in a conveying stream (13), thermal conditioning of the preforms and subsequent forming into containers by means of pressurization with a fluid, characterized by a device according to one of the Claims 14 until 27 .

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