WO2013171141A1

WO2013171141A1 - Installation for producing containers comprising means for transmitting movement at several speeds between a conveyor and a forming station

Info

Publication number: WO2013171141A1
Application number: PCT/EP2013/059768
Authority: WO
Inventors: Yves-Alban Duclos; Nicolas Chomel
Original assignee: Sidel Participations
Priority date: 2012-05-15
Filing date: 2013-05-13
Publication date: 2013-11-21
Also published as: FR2990638A1; EP2849927A1; FR2990638B1

Abstract

ABSTRACT: The invention concerns an installation (10) for producing containers from a thermoplastic material using preforms, the installation (10) comprising: - a thermal conditioning station (12) that is provided with a conveyor (14) for conveying preforms and a first drive shaft (24) of the conveyor (14); - a moulding station (26) that is equipped with a carousel (28) and a second drive shaft (27) of the carousel; - a motor (34) driving one of the drive shafts (24 and 27); - transmission means (38, 40, 42) for transmitting movement between the first drive shaft (24) and the second drive shaft (27); characterised in that the transmission means comprise members (40, 44, 46 and 58) controlled to selectively transmit movement between the first drive shaft (24) and the second drive shaft (27) according to a first speed ratio (R1) or according to a second speed ratio (R2).

Description

"Container manufacturing plant having multi-speed motion transmission means between a conveyor and a forming station"

The invention relates to an installation for manufacturing containers made of thermoplastic material comprising a thermal conditioning station and a molding station.

The invention relates more particularly to an installation for manufacturing containers made of thermoplastic material from preforms, the installation comprising:

a preform thermal conditioning station which is equipped with a preform conveyor, the station comprising a first drive shaft of the conveyor;

- A molding station which is equipped with a carousel carrying a plurality of molding devices which are fed in preforms by the conditioning station, the station comprising a second drive shaft of the carousel;

a drive motor of the first drive shaft or the second drive shaft;

- Motion transmission means between the first drive shaft and the second drive shaft according to a first gear ratio.

The manufacture of thermoplastic containers, such as bottles, flasks, etc. is performed during a step of forming containers in the form of a blank, which are sometimes called preforms.

Prior to the implementation of the forming step, the preforms go through a thermal conditioning step. During this step, the preforms are heated in a thermal conditioning station, or oven, so as to give them a sufficiently malleable structure for the forming process.

These preforms are then transferred to a molding station which has a plurality of molding devices. Each preform is introduced into a mold of the molding device. The molding device also comprises means for blowing or stretch-blow molding.

These facilities generally represent a significant financial investment for the container manufacturer. For this reason, it is advantageous that the same installation can be used to manufacture series of containers of various sizes.

For this purpose, the installation has many elements that are adapted to the format of the final container to obtain. These elements are sometimes called "personalization elements". Among these elements, one can for example quote the molds of the molding station. Preforms gripping means can also be mentioned to enable the conveying of preforms having necks of different sizes through the thermal conditioning station.

In the thermal conditioning station, the body of the preforms is heated for a predetermined period. In addition, depending on the shape of the final container, the body of the preforms may be heated in a non-homogeneous manner according to a determined profile. To allow precise heating of the preforms, they are conveyed in a heating tunnel of the conditioning station, along a predetermined path.

The preforms thus heated are transferred from an output of the thermal conditioning station to an entry point of the molding station. During blow molding, the molding devices are moved so that the final containers are demolded at an exit point of the installation. For this purpose, the molding devices are for example mounted on a carousel.

A blow molding or stretch blow molding cycle is substantially faster than a heat-conditioning cycle of a preform. As a result, the thermal conditioning station receives substantially more preforms as the molding station. According to a nonlimiting example, the molding station comprises a dozen molding devices while the conveyor of the packaging station is capable of accommodating a hundred preforms.

In addition, the preforms are moved through these two stations synchronously so that each preform is heated to a precise temperature when it is transferred to a molding device. To do this, the carousel of the molding station and the conveyor of the conditioning station are rotated by a common drive motor. The motor generally drives the carousel of the molding station, the drive movement being transmitted to the conveyor of the conditioning station by means of transmission means according to a precise speed ratio, said manufacturing, allowing the synchronous operation of two stations for the manufacture of containers.

In this manufacturing configuration, a so-called "non-reference" pitch of the molds is defined, which is equal to the angle of rotation of the carousel for a molding device to replace the directly preceding molding device at the level of the carousel. entry point of the molding station.

Similarly, it defines a running step of the gripping means, said "no manufacturing", which corresponds to the movement of the conveyor necessary for a gripping means to take the place of the gripping means directly preceding the output of the the thermal conditioning station. The manufacturing speed ratio makes it possible to synchronize the carousel and the conveyor so that the movement of the molds of a reference step corresponds to the movement of the gripping means of a manufacturing step.

In order to change the format of containers, it is necessary to discontinue the manufacture of containers for immobilize the installation. The old personalization elements are then replaced by new personalization elements adapted to the new container format to obtain. This step can be performed either by human operators or by automata.

When changing format, the motor is controlled so as to scroll the molding devices one after another in front of a first replacement area. At each reference step, the engine marks a stop to allow replacement operations to take place during a format change step. This is not a problem because the mussels are few and they can be changed one by one without taking too much time.

Alternatively, the replacement area is likely to accommodate two molds. We can then scroll the molds of two reference steps between each replacement operation.

Similarly, during said change of format, the gripping means must successively mark a stop in front of a second replacement zone to be replaced. The gripping means are very numerous, it is therefore advantageous to be able to replace several during each replacement operation. The gripping means being compact and light enough, it is easy to simultaneously receive a series of several gripping means in the second replacement zone.

Thus, during a change of format, it would be advantageous to scroll the gripping means of a second step larger than the manufacturing step. This second step will be called "no replacement". When the conveyor advances by a replacement step, a series of gripping means takes the place of a directly preceding series in the replacement zone. Advantageously, the gripping means are replaced at the same time as the molds in order to save time. However, if we keep the manufacturing speed ratio to scroll the gripping means, we can only replace a single gripping means at each run of a mold. This results in a waste of time.

Indeed, the gear ratio of the transmission mechanism does not allow to scroll simultaneously the carousel of a reference pitch and the conveyor of a replacement step.

To make a format change, it is therefore known to replace, initially, the personalization elements of the molding station by adopting a first pitch of the motor corresponding to the reference pitch, then, in a second step , the elements of the conditioning station by adopting a second pitch of the engine corresponding to the replacement step of the gripping means.

However, this solution does not allow a quick change of format.

In order to make it possible to optimize the format changeover time simply and inexpensively, the invention proposes an installation of the type described above, characterized in that the transmission means comprise controlled elements for selectively transmitting the movement between the first shaft. and the second drive shaft is in the first gear ratio, or in at least one second gear ratio.

According to other features of the invention:

the transmission means comprise: a first transmission mechanism according to the first gear ratio between the first drive shaft and the second drive shaft;

a second transmission mechanism according to the second gear ratio between the first drive shaft and the second drive shaft;

at least one gear selection device which selectively couples the second drive shaft with the first drive shaft via the first transmission mechanism or the second transmission mechanism;

- The gear selection device is likely to occupy a position of "neutral" in which the first shaft is not coupled with the second shaft;

each transmission mechanism comprises:

- a drive wheel which is mounted free to rotate relative to the drive shafts;

- Temporary coupling means of the second freewheel which can be controlled between an engaged state in which the freewheel is connected in rotation with the drive shafts, and a disengaged state in which the rotational link between the free wheel and the drive shafts is interrupted;

- For at least one of the transmission mechanisms, the free wheel is carried directly by one of the drive shafts;

the free wheel is carried by the drive shaft of the conveyor;

for at least one of the transmission mechanisms, the free wheel is carried by an intermediate shaft between the two drive shafts; - The free wheel is rotatably connected with at least one of the drive shafts via at least one flexible connecting member, such as a belt;

- The temporary coupling means are formed by a dog clutch system;

- The coupling means are formed by a friction clutch system.

Other features and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

- Figure 1 is a top view which schematically shows a container manufacturing plant made according to the teachings of the invention;

- Figure 2 is a side view which shows the means for transmitting movement between the carousel and the conveyor which are made according to the teachings of the invention.

In the remainder of the description, the longitudinal, vertical and transverse orientations indicated by the "L, V, T" trihedron of the figures will be adopted in a nonlimiting manner.

In the rest of the description, elements having identical structure or similar functions will be indicated by the same reference numbers.

FIG. 1 shows a plant 10 for manufacturing containers made of thermoplastic material from preforms (not shown).

Such preforms are generally obtained by injection and have a tubular cylindrical body closed at one of its axial ends, and which is extended at its other end by a neck, also tubular. The neck is usually injected so as to have already its final shape while the body of the preform is called to undergo a deformation relatively large to form the final container during the forming step.

The installation 10 comprises a preform thermal conditioning station 12 which is equipped with a conveyor 14 comprising a plurality of means (not shown) for gripping preforms.

The thermal conditioning station 12 more particularly comprises a fixed tunnel which is equipped with means (not shown) for heating, such as infrared lamps. The tunnel is traversed by the conveyor 14. The preform gripping means are arranged one behind the other on the conveyor 14 so as to be spaced apart from each other by a determined pitch.

The gripping means are intended to grip the preforms by their neck so as to allow the free body to be heated by the heating means. Each gripping means is adapted to the dimensions of the neck of the containers during manufacture. Depending on the container size, the neck may have different diameters and / or heights. These gripping means thus form personalization elements that must be changed during a container size change step.

Examples of gripping means of this type are described in more detail in patent document WO-A1-2011 / 069877.

The preforms are thus conveyed in a queue along the tunnel from an inlet 16 to an outlet 18 of the tunnel, so that their bodies are heated to a predetermined profile.

The conveyor 14 is for example formed by a chain of which each link carries a gripping means. The conveyor chain 14 is closed around two guide wheels 20, 22 which are arranged at two ends of the packaging station 12. The first guide wheel 20 is rotatably mounted about a vertical "A" axis via a first drive shaft 24, while the second guide wheel is rotatably mounted about an "B" axis. vertical. The first drive shaft 24 will hereafter be called "conveyor shaft 24".

The inlet 16 and the exit 18 of the tunnel are arranged close to the first guide wheel 20. According to this configuration, the tunnel here forms a "U", the preforms making a turn at the second guide wheel 22.

The first guide wheel 20 forms a driving wheel 20 for the conveyor 14 while the second wheel 22 forms a driven wheel 22. The rotating drive means 24 of the conveyor shaft will be detailed later.

Close to the exit 18 of the station 12 of conditioning is arranged a station 26 of molding. The molding station 26 comprises a carousel 28 which is rotatably mounted about a vertical axis "C" via a second drive shaft 27. The second drive shaft 27 will be referred to hereafter as "carousel shaft 27".

The carousel 28 carries at its periphery a plurality of molding devices (not shown). Each molding device comprises a removable mold which delimits a molding cavity. The molding cavity is intended to receive an outgoing preform still hot from the station 12 of conditioning. Each molding device also comprises a nozzle (not shown) associated blow molding or stretch-blow molding which is intended to give the container its final shape by pressing the malleable walls of the preform against the walls of the mold cavity by introduction of a fluid under pressure through the neck of the preform.

To make containers of different sizes, it is possible to replace the molds to replace them with other molds having mold cavities of different shape. The molds thus form elements of personalization.

Similarly, the nozzles have elements that are adapted to the dimensions of the neck of the container being manufactured. These personalization elements are also likely to be replaced during a format change step.

Molds of this type are for example described in EP-A1-0 0821 641.

During the container molding step, the carousel 28 is rotated to allow the preforms / end containers to move from an entry point 29 to an exit point 31. Thus, a new preform can begin the molding step while the previous preform has not yet completed its forming cycle in the associated molding device. This makes it possible to maintain a high rate for the mass production of the containers.

The molding station 26 also comprises a transfer wheel 30 which is interposed between the outlet 18 of the conditioning station 12 and the entry point 29 on the carousel 28. The transfer wheel 30 is rotatably mounted about an axis "D" vertical via a central shaft 32, which will be called thereafter "transfer shaft 32". The transfer wheel 30 has gripping members (not shown) at its periphery for transferring the hot preforms from the conveyor 14 to a mold of the carousel 28.

The molding station 26 also comprises a wheel 33 for evacuating the final containers which is arranged to receive the final containers at the exit point 31 of the carousel 28. The evacuation wheel 33 has a structure similar to that of the wheel 30 transfer.

The conveyor 14, the transfer wheel 30 and the carousel 28 must operate synchronously so that the preforms run continuously from the inlet 16 of the conditioning station 12 to the outlet point 31 of the molding station 26.

The carousel 28 is rotated by a drive motor 34 which rotates the shaft 27 of the carousel. The rotational movement of the carousel 28 is transmitted along a kinematic chain first passing through the transfer shaft 32, then the movement of the transfer shaft 32 is transmitted to the conveyor shaft 24. The motion transmission along the drive train from the carousel shaft 27 to the conveyor shaft 24 is performed by transmission means 35.

The transmission means 35 comprise, for example, belts and / or gear trains or any other known mechanical transmission means.

The transmission means 35 transmit the movement between the carousel shaft 27 and the conveyor shaft 24 in a first gear ratio "R1" determined, said ratio "R1" manufacturing speeds.

The first ratio "R1" manufacturing speeds is set so that all these movable elements are synchronized during operation in a "manufacturing" mode during the manufacture of large-scale containers. In "manufacturing" mode, the motor 34 operates continuously at a constant speed so as to cycle the preforms without interruption from the input 16 to the exit point 31.

Thus, when the carousel 28 rotates with a first "PO" reference step to bring a next mold at the point of entry 29, the conveyor 14 advances a first step "P1" of manufacture allowing bring a next gripping means at the outlet 18.

However, when it is desired to change container format, it is necessary to proceed with the replacement of elements of personalization. The motor 34 is then controlled so as to scroll each molding device step by step in front of a first replacement zone according to the first "PO" reference step, the motor 34 marking a stop time at each step to allow time. to replace the mold and other personalization elements.

The motor 34 is also controlled so as to scroll step by step a series of gripping means of the conveyor 14 in front of a second replacement zone according to a second pitch "P2" called replacement. The second replacement zone is capable of accommodating a series of several adjacent gripping means. With each step "P2" replacement, the next series of gripping means takes the place of the series that has just occupied the second replacement zone before the engine marks a new stop to allow the replacement of all means of the series which is stopped in front of the second replacement zone.

The second step "P2" replacing the gripping means is substantially larger than the first step "P1" of manufacture. Thus, the first step "P1" corresponds to a movement of the gripping means one by one in front of the replacement zone, while the second "P2" replacement step corresponds to a movement of the gripping means by series, for example ten by ten, in front of the replacement area.

However, using the first gear ratio "R1" of the "manufacturing" mode, the rotation of the carousel 28 of the first "PO" reference step causes the rotation of the conveyor 14 of the "P1" step of manufacture which does not correspond to the second no "P2" replacement of the gripping means. Thus, during the running of a molding device in front of the first zone of replacement, only one new gripping means arrives in front of the second replacement zone.

To solve this problem, the transmission means 35 of the manufacturing installation 10 comprise controlled members for selectively transmitting the movement between the carousel shaft 27 and the conveyor shaft 24 according to the first gear ratio "R1". of manufacture, or in at least a second ratio "R2" of replacement speeds.

The first gear ratio "R1" corresponds to a running of the molding devices and the gripping means in a synchronized manner during operation in the "manufacturing" mode of the installation 10 so that the rotation of the carousel 28 of a no "PO" reference causes the rotation of the conveyor 14 of the first step "P1" of manufacture. Thus, the preforms carried by each of the gripping means are successively received in a corresponding mold. By way of nonlimiting example, the first ratio "R1" of speeds between the carousel shaft 27 and the conveyor shaft 24 is equal to 0.5, in other words, the conveyor shaft 24 performs a turn when the carousel shaft 27 performs two turns.

The second speed ratio "R2" corresponds to a movement of the molds and gripping means in "format change" mode so that the rotation of the carousel 28 with a reference pitch "P0" causes the conveyor 14 to rotate. second step "P2" replacement. By way of nonlimiting example, the second ratio "R2" of speeds between the carousel shaft 27 and the conveyor shaft 24 is equal to 5, in other words, the conveyor shaft 24 performs five laps when the carousel shaft 27 makes a turn.

In the embodiment of the invention shown in FIG. 2, the control members are arranged on the kinematic chain portion which is between the transfer wheel 30 and the conveyor 14. Alternatively, it will be understood that the control members may be arranged on another portion of the drive train between the carousel shaft 27 and the conveyor shaft 24.

The transmission means 35 thus comprise a first transmission mechanism 36 according to the first gear ratio "R1" between the conveyor shaft 24 and the carousel shaft 27.

The first mechanism 36 here comprises a first toothed drive wheel 38 which is carried in rotationally manner by the transfer shaft 32 and a second toothed drive wheel 40 which is carried by the conveyor shaft 24. Subsequently these two wheels 38, 40 will be called respectively "first primary wheel 38" and "second primary wheel 40".

The second primary wheel 40 is rotatably connected to the first primary wheel 38 via a flexible connecting member 42, such as a belt.

The transmission means 35 also comprise a second transmission mechanism 48 according to the second ratio "R2" of speeds between the conveyor shaft 24 and the carousel shaft 27.

The second mechanism 48 here comprises a first toothed drive wheel 50 which is supported, in rotationally integral manner, by the transfer shaft 32 and a second toothed drive wheel 52 which is carried by the conveyor shaft 24. 14.

To obtain the second gear ratio "R2", the second mechanism 48 here comprises an intermediate vertical shaft 54 which is rotatably mounted about a vertical axis "E". The vertical shaft 54 carries a third drive wheel 56 which is arranged at the same height as the first drive wheel 50 and carries a fourth wheel 58 drive which is mounted below the third wheel 56, at the same height as the second drive wheel 52.

These four wheels 50, 52, 56, 58 will hereinafter be referred to as "first secondary wheel 50", "second secondary wheel 52", "third secondary wheel 56" and "fourth secondary wheel 58".

The third secondary wheel 56 is connected in rotation with the first secondary wheel 50 via a first flexible connecting member 60, such as a belt,

The second secondary wheel 52 is rotatably connected to the fourth secondary wheel 58 via a second flexible connecting member 62, such as a belt.

The transmission means 35 also comprise at least one speed selection device which selectively couples the carousel shaft 27 with the conveyor shaft 24 via the first transmission mechanism 36 or the second transmission mechanism 48. transmission.

To do this, for each transmission mechanism 36, 48, one of the drive wheels is free to rotate about the shaft carrying it, while all the other drive wheels are rotatably connected to the shaft which drives them. door.

The gear selection device comprises temporary coupling means of the freewheel with the shaft which carries it which can be controlled between an engaged state in which the freewheel is connected in rotation with the shaft which door, and a disengaged state in which the connection in rotation between the freewheel and the shaft which carries it is interrupted.

Thus, for the first transmission mechanism 36, the second primary wheel 40 is rotatably mounted around the conveyor shaft 24. The second primary wheel 40 is capable of being secured in rotation with the conveyor shaft 24 by means of temporary coupling means 44 which are carried by the conveyor shaft 24. The temporary coupling device 44 is for example formed by a dog clutch system between a dog element 46 which is mounted vertically sliding and rotatably connected to the conveyor shaft 24. The element 46 of dog is likely to be fitted vertically with the wheel 40 primary.

The dog element 46 is thus capable of being controlled between a lower declutching position in which the primary wheel 40 is free to rotate on the conveyor shaft 24, and an upper clutch position in which the primary wheel 40 is integral in rotation with the conveyor shaft 24 via the dog element 46.

The dog element 46 is for example controlled by means of a control fork (not shown). The command can be manual or automatic.

According to a variant not shown of the invention, the temporary coupling means are formed by a friction clutch system, plane or conical.

For the second transmission mechanism 48, it is the fourth secondary wheel 58 which is mounted free to rotate about its intermediate shaft 54 while all the other secondary wheels 50, 52, 56 are integral in rotation with the shaft 24, 32, 54 who wears them. The fourth secondary wheel 58 is capable of being connected in rotation with its intermediate shaft 54 by means of temporary coupling means 44 which are identical to those of the first mechanism 36.

During the operation of the manufacturing facility 10 in "manufacturing" mode, the means 44 for temporary coupling of the first transmission mechanism 36 occupy their engaged state, while the means 44 for temporarily coupling the second mechanism 48 occupy their state. disengaged. Thus, the conveyor shaft 24 is rotated by the carousel shaft 27 in the first gear ratio "R1". During operation of the manufacturing facility 10 in "format change" mode, the means 44 for temporary coupling of the first transmission mechanism 36 occupy their disengaged state, while the means 44 for temporary coupling of the second mechanism 48 occupy their condition engaged. Thus, the conveyor shaft 24 is rotated by the second shaft 27 of the carousel 28 according to the second gear ratio "R2".

Advantageously, the means 44 for temporary coupling of the two transmission mechanisms 36, 48 are capable of simultaneously occupying their disengaged state. The gear selection device thus occupies a "neutral" position in which the conveyor shaft 24 is not coupled with the carousel shaft 27.

The manufacturing installation 10 equipped with means 35 for transmitting at least two gear ratios produced according to the teachings of the invention makes it possible to reduce the duration of a format change step by synchronizing the reference pitch "PO" of the carousel with the step "P2" of the conveyor replacement.

In addition, such a facility is inexpensive because it includes a single motor 34 to move the conveyor and the carousel, whether in "manufacturing" mode or "format change" mode.

Claims

1. Installation (10) for manufacturing containers made of thermoplastic material from preforms, the installation (10) comprising:

a preform thermal conditioning station (12) which is equipped with a preform conveyor (14), the station (12) comprising a first drive shaft (24) of the conveyor (14);

- a molding station (26) which is equipped with a carousel (28) carrying a plurality of molding devices which are fed in preforms by the conditioning station, the station (26) comprising a second shaft (27) of carousel training;

a drive motor (34) for driving the first drive shaft (24) or the second drive shaft (27);

means (35) for transmitting motion between the first drive shaft (24) and the second drive shaft (27) in a first gear ratio (R1);

characterized in that the transmission means (35) comprise members (40, 44, 46, 58) controlled to selectively transmit motion between the first drive shaft (24) and the second drive shaft (27). according to the first gear ratio (R1), or in at least one second gear ratio (R2).

2. Installation (10) according to the preceding claim, characterized in that the transmission means (35) comprise:

- a first transmission mechanism (36) according to the first gear ratio (R1) between the first drive shaft (24) and the second drive shaft (27);

a second transmission mechanism (48) according to the second gear ratio (R2) between the first drive shaft (24) and the second drive shaft (27); at least one gear selection device (44, 46) for selectively coupling the second drive shaft (24) to the first drive shaft (27) via the first drive mechanism (36). transmission or the second transmission mechanism (48).

3. Installation (10) according to the preceding claim, characterized in that the device (44, 46) gear selection is likely to occupy a position of "neutral" in which the first shaft (24) is not coupled with the second shaft (27).

4. Installation (10) according to any one of claims 2 or 3, characterized in that each transmission mechanism (36, 48) comprises:

- a drive wheel (40, 58) which is rotatably mounted relative to the drive shafts (24, 27);

means (44, 46) for temporary coupling of the second freewheel which can be controlled between an engaged state in which the free wheel (40, 58) is rotatably connected with the shafts (24, 27) drive, and a disengaged state in which the rotational connection between the free wheel (40, 58) and the drive shafts (24, 27) is interrupted.

5. Installation according to the preceding claim, characterized in that, for at least one of the transmission mechanisms (36), the free wheel (40) is carried directly by one of the shafts (24) drive.

6. Installation (10) according to the preceding claim, characterized in that the free wheel (40) is carried by the shaft (24) for driving the conveyor (14).

7. Installation (10) according to any one of claims 4 to 6, characterized in that, for at least one of the transmission mechanisms (48), the free wheel (58) is carried by a shaft (54) intermediate between the two drive shafts (24, 27).

8. Installation (10) according to any one of claims 4 to 7, characterized in that the free wheel (40, 58) is rotatably connected to at least one of the drive shafts (24, 27). via at least one flexible connecting member (42, 60, 62), such as a belt.

9. Installation (10) according to any one of claims 4 to 8, characterized in that the temporary coupling means are formed by a dog clutch system (46).

10. Installation according to any one of claims 4 to 8, characterized in that the coupling means are formed by a friction clutch system.