WO2021165615A1

WO2021165615A1 - Installation for the manufacture of aluminium or aluminium alloy containers, preferably designed to contain a beverage, the forming unit of which comprises retractable fingers

Info

Publication number: WO2021165615A1
Application number: PCT/FR2021/050279
Authority: WO
Inventors: Laurent LASZCZYK; Thierry BAYLE
Original assignee: Constellium Neuf-Brisach; Constellium Muscle Shoals Llc
Priority date: 2020-02-18
Filing date: 2021-02-17
Publication date: 2021-08-26
Also published as: FR3107199A1; FR3107199B1

Abstract

What is described is an installation for the manufacture of aluminium or aluminium alloy containers. A punch nose (22) varies between a first configuration in which it delimits a first spatial imprint such that, during the passage of the punch (20) from a retracted position to a first intermediate position, the punch (20) and the die assemblies, including the third die assembly (30), progressively deform by forming the unitary cup (500) in a manner making it possible to temporarily form a preform (100'), a bottom wall (102) and a connecting wall (103) of which have a constant cross section around a longitudinal axis (X), and a second configuration in which it delimits a second spatial imprint such that, in an extended position of the punch (20), the connecting wall (103) of the container (100) obtained by forming between the punch (20) and the third die assembly (30) has a variable cross section around the longitudinal axis (X).

Description

DESCRIPTION

TITLE: Installation for the manufacture of aluminum or aluminum alloy containers, preferably adapted to contain a beverage, the forming unit of which includes retractable fingers

Technical field of the invention

The present invention relates to an installation for the manufacture of aluminum or aluminum alloy containers, preferably adapted to contain a beverage, configured so that each manufactured container is formed in one piece and defines a cylindrical side wall, a wall of essentially concave bottom and a connecting wall connecting the side wall and the bottom wall, the side wall having an upper edge opposite the bottom wall allowing the subsequent sealed attachment of a cover to form a closed box, the connecting wall delimiting: a support ring having a convexity oriented on the side opposite to the internal volume delimited by the side wall, and a connecting portion between the support ring and the side wall, the installation comprising a forming unit adapted to transform a unitary cup so as to form the bottom wall, the connecting wall and all or part of the side wall, the unit of f ormage comprising: a frame delimiting a passage comprising a longitudinal axis, a punch disposed in the passage delimited by the frame movably along the longitudinal axis between a retracted position and an extended position, the punch delimiting a main body and a punch nose located at one end of the main body, three successive die sets cooperating with the punch, so that, during the passage of the punch from the retracted position to the extended position, each unit cup placed between one of the sets- dies and the punch undergoes a reduction in diameter (first assembly-die), then stretching to form the side wall (second assembly-die), then shaping of the bottom wall and of the connecting wall of the preform (third set-matrix).

State of the art

There are already facilities capable of manufacturing aluminum or aluminum alloy containers, preferably adapted to contain a drink. Once the cover is fixed to the upper edge of the container, in particular after filling the container, the result is the manufacture of a closed and sealed box. The manufacture of containers is carried out at a very high rate, typically of the order of 200 to 400 containers manufactured per minute.

It is known that the installation comprises a first cutting unit suitable for cutting individual discs in an aluminum or aluminum alloy strip. A known installation also comprises a stamping unit adapted to transform each unit disc into a unit cup by stamping. Then, within a forming unit, each unit cup undergoes a reduction in diameter thanks to a first re-stamping die assembly to obtain a re-stamped cup, then a stretching operation to form the side wall and obtaining a preform by means of a second assembly-drawing die, then a shaping operation allowing the lower part of the preform to be shaped by means of a third assembly-shaping die to obtain a container. An installation then comprises a second cutting unit for cutting the upper edge of the side wall of the container, a cleaning unit, a coating unit for forming a suitable coating on the interior face of the container, a unit for forming exterior decorations on it. the outer face of the container, typically by printing, a heating unit to subject the container to the appropriate heat treatments, a shrinkage unit to form a narrowed neck at the level of the upper edge of the side wall of the container, a possible reforming step of the bottom, a possible blowing unit in which the container undergoes a controlled expansion in order to shape it. After filling, the container is intended to allow, at its upper edge, the tight fixing of a cover to obtain a box.

Conventionally, a forming unit comprises a frame delimiting a passage comprising a longitudinal axis, a punch disposed in the passage delimited by the frame movably along the longitudinal axis between a retracted position and an extended position, the punch delimiting a main body and a punch nose located at one end of the main body, a moving actuator urging the main body so as to move the punch at least from the retracted position to the extended position, and three successive die sets cooperating with the punch . The first re-stamping die assembly typically includes a cup clamp and a re-stamping ring. The second drawing die assembly generally comprises several successive drawing rings (for example 3), having decreasing diameters in order to increase the height while reducing the thickness of the. side wall. The third set-die generally comprises a support allowing the shaping of the bottom wall and of the connecting wall. The die assemblies and the punch cooperate together and are configured such that, during the passage of the punch from the retracted position to the extended position:

- Each unit cup placed between the first set-die and the punch undergoes a reduction in diameter to obtain a re-stamped cup;

- Then each re-stamped cup placed between the second die assembly and the punch undergoes stretching to form the side wall and obtain a preform;

- Then each preform placed between the third assembly-die and the punch undergoes shaping of the bottom wall and of the connecting wall of the preform to obtain a container.

It is necessary to ensure that the container has sufficient mechanical rigidity for further manufacture and for its use. This mechanical resistance relates in particular to the axial resistance to allow the crimping of the lid and the stacking of the boxes, the resistance to internal pressure which is liable to vary during the filling of the container and during the transport and storage of the boxes, the resistance to falling boxes after filling, etc ...

To provide sufficient mechanical resistance, it has already been imagined to structure the bottom wall and / or the connecting wall, so as to increase the mechanical resistance locally according to a principle of ribs or bosses in the lower part of the container. .

By way of example, such solutions have been described in documents US Pat.

But one of the difficulties is to achieve the manufacture of such containers in a simple, efficient, economical, and with great reliability to avoid as much as possible the manufacturing problems and untimely stoppages of the manufacturing line which are likely to occur. to have very large impacts given the very high production rates. Indeed, it was determined by simulations and tests that the presence of a non-homogeneous geometry at the level of the connecting wall, in particular at the level of the support ring and / or of the connecting portion between the support ring and the side wall, has the effect of opposing the sliding of the material during forming between the punch and the die assembly.

There is first a risk of rupture, in the form of tearing of the material of the bottom of the unit cup because of the punch having asymmetrical shapes, for example crenellations, at the time of re-stamping for reduction of diameter of the unitary cup. There is also a risk of reduction of thickness, or even of rupture, during the shaping of the final bottom wall. Finally, there is a risk of seeing folds appear during the shaping of the bottom or the re-stamping due to the asymmetry of the cutting section.

Object of the invention

The object of the present invention is to provide an installation for the manufacture of aluminum or aluminum alloy containers which meets all or part of the problems presented above.

In particular, the aim of the invention is to provide an installation for the manufacture of aluminum or aluminum alloy containers which meets at least one of the following objectives: to be simple and economical, to be efficient and to guarantee a high rate. workmanship, be reliable.

This goal can be achieved through the implementation of an installation for the manufacture of aluminum or aluminum alloy containers, preferably adapted to contain a drink, configured so that each container manufactured is formed in one piece and delimits a cylindrical side wall, a substantially concave bottom wall and a connecting wall connecting the side wall and the bottom wall, the side wall having an upper edge opposite the bottom wall allowing the subsequent sealed attachment of a cover for constitute a closed box, the connecting wall delimiting: a support ring having a convexity oriented on the side opposite the internal volume delimited by the side wall, and a connecting portion between the support ring and the side wall, installation comprising a forming unit adapted to transform a unitary cup so as to form the bottom wall, the connecting wall and all or part of the wall l lateral, the forming unit comprising: a frame delimiting a passage comprising a longitudinal axis, a punch disposed in the passage delimited by the frame movably along the longitudinal axis between a retracted position and an extended position, the punch delimiting a main body and a punch nose located at one end of the main body, a first re-stamping die assembly comprising a cup clamp and a re-stamping ring, a second drawing die assembly comprising a plurality of rings successive draws (e.g. 3), having decreasing diameters in order to increase the height while reducing the thickness of the side wall, a third bottom wall and connecting wall forming die assembly, the die assemblies and the punch cooperating together and being configured such that during passage of the punch from the retracted position to the extended position:

- each unit cup placed between the first set-die and the punch undergoes a reduction in diameter to obtain a re-stamped cup,

- then each re-stamped cup placed between the second assembly-die and the punch undergoes stretching to form the side wall and obtain a preform,

- then each preform placed between the third assembly-die and the punch undergoes shaping of the bottom wall and of the connecting wall of the preform to obtain a container, the installation being such as a functional element belonging to the group comprising the third die assembly and the punch nose, is configured to vary between: a first configuration, automatically adopted when the punch is axially positioned between the retracted position and a first intermediate position situated between the retracted position and the position outlet, in which the functional element defines a first spatial imprint such that, during the passage of the punch from the retracted position to the first intermediate position, the punch and the die sets, including the third die set, progressively deform by forming the unitary cup in such a way as to temporarily form a preform of which the bottom wall is shaped a dome having a constant cross section around the longitudinal axis and the connecting wall of which has a constant cross section around the longitudinal axis, a second configuration, automatically adopted when the punch is in the extended position, in which the functional element defines a second spatial imprint such as in the extended position of the punch, the connecting wall, in particular at the level of the support ring (104) and / or of the connecting portion (111) between the support ring (104) and the side wall (101), of the container obtained by forming between the punch and the third die assembly has a variable section of cut around the longitudinal axis, the passage of the first configuration to the second configuration being caused automatically by the mechanical forces exerted between the third assembly-die and the punch nose during the passage of the punch from the first intermediate position to the position tion output. According to the arrangements presented above, the result is that the forming unit advantageously divides the forming operations of the lower part of each preform and then each container into two phases. In a first phase, which corresponds to the period of movement of the punch from the retracted position to the first intermediate position, the forming unit makes it possible to form the bottom wall and the connecting wall of the preform in such a way that the wall bottom and the connecting wall both have an axial symmetry about the longitudinal axis. Then, in a second posterior phase, which corresponds to the period of movement of the punch from the first intermediate position to the extended position, the forming unit makes it possible to form the connecting wall of the container in such a way that, on the contrary, of the preform obtained temporarily at the end of the first phase, the connecting wall has an axial asymmetry around the longitudinal axis. For example, this results in the possibility of shaping, in the connecting wall, in particular at the level of the support ring and / or of the connecting portion between the support ring and the side wall, concave deformations distributed at regular intervals while rotating around the longitudinal axis, the concavity of these concave deformations being oriented towards the side of the internal volume delimited by the lateral wall of the container, these concave deformations being however absent at the end of the first phase and being generated only during the second phase. Therefore, the forming unit makes it possible to create the axially asymmetric structural elements intended to increase the mechanical rigidity of the lower part of the container during the second phase, after the connecting wall and the bottom wall both, possibly temporarily, axially symmetrical were obtained during the first phase. The numerical simulations carried out by the Applicant have shown that for given material thicknesses where previous forming techniques led to the rupture of the container during forming, the forming unit described in this document guarantees that the container thus formed does not break. during forming, with great reliability.

Certain preferred but non-limiting aspects of the installation are now given below, these can be implemented in isolation or in combination.

The second spatial imprint delimited by the functional element in the second configuration has a shape complementary to the shape of a constant spatial imprint permanently delimited by the other element than the functional element among the group comprising the third set-matrix and the punch nose. The second spatial imprint delimited by the functional element in the second configuration is such that in the extended position of the punch, the connecting wall of the container obtained by forming between the punch and the third die assembly comprises, in particular at the level of the 'support ring and / or the connecting portion between the support ring and the side wall, concave deformations, the concavity of which is oriented on the side of the internal volume delimited by the side wall of the container, and distributed at regular intervals around the longitudinal axis.

In a first variant, the functional element is constituted by the punch nose, the punch nose comprising a fixed part integral with the main body and a plurality of retractable fingers where each retractable finger is mounted on the fixed part of the punch nose. 'a manner movable along the longitudinal axis so as to be able to vary between a deployed position and a retracted position, the punch nose being such that the punch nose delimits: a first forming surface, corresponding to the first spatial impression, having a constant section of cut around the longitudinal axis when each retractable finger occupies the deployed position, a second forming surface, corresponding to the second spatial impression, having a variable section of cut around the longitudinal axis when each retractable finger occupies its retracted position, so as to delimit depressions at the level of each retractable finger in the retracted position where lesd these depressions have spatial shapes corresponding to the concave deformations of the connecting wall of the container.

The punch nose comprises a movable part mounted on the fixed part of the punch nose movably along the longitudinal axis, said movable part being made in one piece and delimiting the plurality of retractable fingers.

The forming unit comprises at least one bias actuator exerting a predetermined mechanical bias of the movable part of the punch nose relative to the fixed part of the punch nose having a threshold value and constraining the movable part of the punch nose in a direction tending to move the retractable fingers towards their deployed position, the retractable fingers being moved towards their retracted position when the movable part of the punch nose undergoes a mechanical force along the longitudinal axis oriented in a direction opposite to the direction according to wherein said predetermined mechanical stress is applied having a value greater than said threshold value. The stress actuator includes a pressure chamber in which an operating fluid is present and the predetermined mechanical stress is obtained by pressurizing the operating fluid.

In a second variant, the functional element is constituted by the third set-die, the third set-die comprising a fixed part and a plurality of retractable fingers where each retractable finger is mounted on the fixed part of the third assembly-die. a manner movable along the longitudinal axis so as to be able to vary between a deployed position and a retracted position, the third die assembly being such that it delimits: a first forming surface, corresponding to the first spatial imprint, having a section of constant cut around the longitudinal axis when each retractable finger occupies its deployed position, a second forming surface, corresponding to the second spatial impression, having a variable section of cut around the longitudinal axis when each retractable finger occupies its position retracted, so as to delimit depressions at each retractable finger in the retracted position where the said depressions have spatial shapes complementary to the projecting portions present between the concave deformations of the connecting wall of the container.

In a third variant, the functional element is constituted by the third set-die, the third set-die comprising a fixed part and a plurality of retractable fingers where each retractable finger is mounted on the fixed part of the third assembly-die. a manner movable along the longitudinal axis so as to be able to vary between a retracted position and a deployed position, the third die assembly being such that it delimits: a first forming surface, corresponding to the first spatial imprint, having a section of constant cut around the longitudinal axis when each retractable finger occupies its retracted position, a second forming surface, corresponding to the second spatial impression, having a variable section of cut around the longitudinal axis when each retractable finger occupies its position deployed, so as to delimit bumps at each retractable finger in the deployed position, where the di your bumps have spatial shapes corresponding to the concave deformations of the connecting wall of the container.

The third die assembly comprises a central fixed die along the longitudinal axis and a movable die having an annular shape delimiting a central opening capable of accommodating the fixed die and movable along the longitudinal axis so as to vary between a lowered position in which the fixed die is disposed in the movable die and a raised position in which the movable die is axially positioned between the fixed die and the punch nose, the movable die being mechanically biased by a mechanism return with respect to the fixed die along the longitudinal axis in a direction urging the movable die towards its raised position, the movable die:

- occupying the raised position when the punch is positioned between the retracted position and a second intermediate position located between the retracted position and the first intermediate position, and automatically moving from the raised position to the lowered position, as opposed to the action of the return mechanism, under the action of moving the punch from the second intermediate position to the extended position.

The mobile die occupies a partially lowered position, axially situated between the lowered position and the raised position, when the punch occupies its first intermediate position.

The punch nose and the main body can be shaped so that in the extended position of the punch, the connecting wall of the container obtained by forming between the punch and the third die assembly comprises, between the support ring and the side wall, a connecting portion having, seen in any section plane passing through the longitudinal axis, a section with a rectilinear profile according to a variant of the present invention. According to another variant, the connecting portion has a variable cross section around the longitudinal axis.

Brief description of the drawings

Other aspects, aims, advantages and characteristics of the invention will become more apparent on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings. on which ones :

[Fig. 1] Figure 1 is a perspective view of the punch of a forming unit of an exemplary installation according to the invention, in the first configuration.

[Fig. 2] Figure 2 is a radial view of the punch of Figure 1.

[Fig. 3] Figure 3 is a radial sectional view showing the punch according to the section plane A-A visible in Figure 2, with two intersecting half-planes at an angle of 15 °.

[Fig. 4] Figure 4 is a perspective view of the punch of Figure 1 in the second configuration. [Fig. 5] Figure 5 is a perspective view of part of the third assembly-die used in an example of installation according to the invention, that is to say the fixed die 31.

[Fig. 6] Figure 6 illustrates in radial section half of the lower part of the container obtained by means of the forming unit.

[Fig. 7] Figure 7 shows schematically in radial section certain parts of the forming unit at a first instant when the punch is in the retracted position.

[Fig. 8] Figure 8 shows schematically in radial section certain parts of the forming unit at a second instant when the punch occupies the second intermediate position.

[Fig. 9] Figure 9 shows schematically in radial section certain parts of the forming unit at a third instant when the punch occupies the first intermediate position.

[Fig. 10] Figure 10 shows schematically in radial section certain parts of the forming unit at a fourth time when the punch occupies the extended position.

[Fig. 11] Figure 11 schematically shows a first cutting unit, before cutting a unit disc.

[Fig. 12] Fig. 12 schematically shows the first cutting unit in the situation after cutting a single disc.

[Fig. 13] Figure 13 shows schematically a stamping unit, in a situation where the unitary disc is partially stamped and the unitary cup is therefore partially formed.

[Fig. 14] Figure 14 shows the stamping unit in the post-stamping situation with the unit cup being formed.

It should be noted that the first and the second die sets are not shown in the figures, because they are well known to those skilled in the art and form part of their general knowledge. This general knowledge can in particular be illustrated by the document “The Aluminum Beverage Can”, William F. Hosford and John, L. Duncan, Scientific American, Sept.1994.

detailed description

In FIGS. 1 to 14 and in the remainder of the description, the same references represent identical or similar elements. In addition, the various elements are not represented to scale so as to favor the clarity of the figures. Furthermore, the different embodiments and variants are not mutually exclusive and can be combined with one another.

The invention relates to an installation for the manufacture of aluminum or aluminum alloy containers, preferably suitable for containing a beverage.

Each container 100 is formed in one piece and delimits a side wall 101 of cylindrical shape, an essentially concave bottom wall 102 and a connecting wall 103 connecting the side wall 101 and the bottom wall 102. The connecting wall 103 defines : a support ring 104 having a convexity oriented on the side opposite to the internal volume 105 delimited by the side wall 101, and a connecting portion 111 between the support ring 104 and the side wall 101. The upper edge of the side wall 101 of the container 100, axially opposite to the bottom wall 102, is intended to subsequently allow the sealed attachment of a cover, not shown, to form a closed box.

Referring to Figures 11 and 12, the installation comprises a first cutting unit suitable for cutting individual discs 200 in a strip 300 of aluminum or aluminum alloy. Typically, it is an AA3101 material, for example in the H14 or H19 metallurgical state. Typically, it is an AA3104 or AA3105 material, for example in the H14 or H19 metallurgical state. The strip 300 may have a thickness of 150 to 300 μm, preferably of 200 to 265 μm, and more preferably between 210 to 245 μm.

FIG. 11 schematically represents the first cutting unit before cutting a unitary disc 200. The strip 300 is placed in a cutting die 400 capable of moving according to a displacement 401 relative to the strip 300 transversely thereto. , that is, in the direction 402 corresponding to its thickness after the strip 300 is placed in the cutting die 400.

Fig. 12 schematically shows the first cutting unit in the situation after cutting the unit disc 200, i.e. after moving 401 of the cutting die 400 in the direction 402 with respect to the web 300.

The installation comprises a stamping unit adapted to transform the unit disc 200 into a unit cup 500 by stamping. In the particular example, maximizing the effectiveness, size, costs, efficiency, practicality and efficiency, the stamping unit is formed at least partially inside the first cutting unit d 'such that the single disk 200 produced by the first cutting unit is used by the stamping unit directly after it is obtained by means of the first cutting unit, without any transfer from the first cutting unit to the stamping unit. In this case, it is then a matter of a first cutting and stamping unit, the first cutting and stamping being carried out in the same unit, one directly following the other.

The stamping unit comprises a stamping die 600 receiving the unit disc 200 with a possibility of stretching and sliding and a stamping punch 601 capable of performing a displacement 603 relative to the stamping die 600 in a direction 602 oriented transversely to the unitary disc 200, that is to say along the thickness of the unitary disc 200.

Fig. 13 schematically shows the stamping unit, in a situation where the unitary disc 200 has been partially stamped and the unitary cup 500 is therefore partially formed. FIG. 14 shows the stamping unit in the situation after stamping, the unit cup 500 having been formed after the movement 603 of the stamping punch 601 relative to the stamping die 600.

The installation comprises a forming unit suitable for transforming the unit cup 500 by forming so as to shape all or part of the container 100, in particular the lower part where the connecting wall 103 and the bottom wall 102 are present.

With reference to FIG. 3, the forming unit comprises a frame 10 delimiting a passage 11 comprising a longitudinal axis X. The nature of the frame 10 and of the passage 11 is of no particular importance and may be of any kind.

The forming unit comprises a punch 20 disposed in the passage 11 delimited by the frame 10 movably along the longitudinal axis X between a retracted position and an extended position.

The punch 20 defines a main body 21 and a punch nose 22 located at one end of the main body 21. The main body 21 and the punch nose can be formed in a one-piece punch and can be made of two separate pieces attached to the punch. one over the other.

The forming unit comprises a moving actuator (not shown) urging the main body 21 so as to move the punch 20 at least from the retracted position shown in Figure 7 to the extended position shown in Figure 10. The nature of the moving actuator has no particular importance and can be arbitrary. It can typically be a moving actuator operating by pneumatic. The return of the punch 20 from the extended position to the retracted position can be achieved by the moving actuator or by an elastic return means of a mechanical, pneumatic or hydraulic nature.

The forming unit comprises a first and a second die set (not shown) and a third die set 30 cooperating with the punch 20, the die sets, including the third die set 30, and the punch 20 being configured. so that, during the passage of the punch 20 from the retracted position (figure 7) to the extended position (figure 10), each unit cup 500, then each re-drawn cup then each preform 100 ', placed between an assembly-die and the punch 20 undergoes a reduction in diameter (first assembly-die, not shown), then a stretching to form the side wall 101 of the preform 100 '(second assembly-die, not shown), then a shaping of the bottom wall 102 and the connecting wall 103 of the container 100 (third set-matrix 30).

Advantageously, a functional element, which is constituted by the third assembly-die 30 in one variant or by the punch nose 22 in another variant, is configured so as to vary between: a first configuration in which the functional element delimits a first spatial imprint such that, during the passage of the punch 20 from the retracted position (Figure 7) to a first intermediate position shown in Figure 9 located between the retracted position and the extended position, the punch 20 and the die sets, including the third die assembly 30, progressively deform by forming the unitary cup 500 in a manner allowing to form a preform 100 'whose bottom wall 102 has the shape of a dome having a constant cross section around the axis longitudinal X and the connecting wall 103 of which also has a constant cross section around the longitudinal axis X, a second configuration in which the element functions ctional delimits a second spatial imprint different from the first spatial imprint and such that in the extended position (FIG. 10) of the punch 20, the connecting wall 103 (in particular at the level of the support ring and / or of the portion connection between the support ring and the side wall) of the container 100 obtained by forming between the punch 20 and the third die assembly 30 has a variable section of cut around the longitudinal axis X.

The first configuration is automatically adopted as long as the punch 20 is axially positioned between the retracted position (Figure 7) and the first intermediate position (Figure 9). The second configuration is automatically adopted when the punch 20 is in the extended position.

The passage from the first configuration to the second configuration is caused automatically by the mechanical forces Fl exerted between the third assembly-die 30 and the punch nose 22 during the passage of the punch 20 from the first intermediate position (FIG. 9) to the position outlet (figure 10).

In general, the second spatial imprint delimited by the functional element adopting the second configuration has a shape complementary to the shape of a constant spatial imprint permanently delimited by the other element than the functional element from among the group comprising the third. die set 30 and the punch nose 22.

The second spatial imprint delimited by the functional element adopting the second configuration is such that in the extended position of the punch 20 (FIG. 10), the connecting wall 103 (in particular at the level of the support ring 104 and / or of the connecting portion 111 between the support ring 104 and the side wall 101) of the container 100 obtained by forming between the punch 20 and the third die assembly 30 comprises concave deformations 106 (FIG. 6), the concavity of which is oriented on the side of the internal volume 105 delimited by the side wall 101 of the container 100, and distributed at regular intervals around the longitudinal axis X.

The depth of the concave deformations 106 counted along the longitudinal axis X is from 0.5 to 1 mm, preferably from 0.7 to 0.8 mm.

In a first embodiment as illustrated in the figures, the functional element is constituted by the punch nose 22. To this end, the punch nose 22 comprises a fixed part 220 integral with the main body 21 and a plurality of retractable fingers 221 where each retractable finger 221 is mounted on the fixed part 220 of the punch nose 22 in a manner movable along the longitudinal axis X so as to be able to vary between a deployed position (figure 1) and a retracted position (figure 4).

Referring to Figures 1 to 4 and 7 to 10, the punch nose 22 is shaped so as to be able to delimit: a first forming surface (Figures 1 and 7 to 9), corresponding to the first spatial imprint, having a section of constant cutting around the longitudinal axis X when each retractable finger 221 occupies the deployed position, a second forming surface (Figures 4 and 10), corresponding to the second spatial imprint, having a cutting section which varies around the axis longitudinal X when each retractable finger 221 occupies its retracted position, so as to delimit depressions 222 at each retractable finger 221 in the retracted position.

Said depressions 222 have spatial shapes corresponding to the concave deformations 106 of the connecting wall 103 of the container 100 obtained by forming between the punch 20 and the third assembly-die 30. In an identical manner to the concave deformations 106, the depressions 222 and therefore more generally the retractable fingers 221 are distributed at regular intervals around the longitudinal axis X.

The second spatial imprint delimited by the functional element constituted by the punch nose 22 when the latter adopts the second configuration is shown in FIG. 4. This second spatial imprint has a shape complementary to the shape of a delimited constant spatial imprint. permanently by the other element than the functional element from the group comprising the third die assembly 30 and the punch nose 22, that is to say the third die assembly 30 in this case. The constant spatial footprint delimited by the third set-matrix 30 is visible in FIG. 5. A fixed matrix 31 described later comprises protrusions 310 having shapes complementary to the depressions 222. The protrusions 310 and the depressions 222 are adapted to come. into each other by interlocking when the punch 20 comes to occupy the extended position in a manner then creating the concave deformations 106. In an identical manner to the concave deformations 106 and to the depressions 222, the projections 310 are distributed at regular intervals around the 'longitudinal axis X. The protrusions 310 are connected by annular groove portions 311 of complementary shapes to the protruding portions 223 of the fixed part 220 located between the depressions 222, so that these protruding portions 223 of the fixed part 220 can come s 'fit into the annular groove portions 311 when the punch 20 is in the extended position in a manner creating the porti ons protruding 110 (Figure 6) located between the concave deformations 106.

According to a particular non-limiting embodiment, the punch nose 22 comprises a movable part 224 mounted on the fixed part 220 of the punch nose 22 in a movable manner along the longitudinal axis X, this movable part 224 being made up of a single piece and delimiting the plurality of retractable fingers 21 as a unit.

The forming unit comprises at least one bias actuator 40 exerting a predetermined mechanical bias F2 of the movable part 224 with respect to the fixed part 220 of the punch nose 22 having a threshold value and constraining the movable part 224 of the punch nose 22 in a direction tending to move the fingers retractable 221 to their deployed positions. The retractable fingers 221 are moved towards their retracted positions when the movable part 224 undergoes a mechanical force F3 along the longitudinal axis X oriented in a direction opposite to the direction in which the predetermined mechanical stress F2 is applied, having a value greater than said threshold value.

Advantageously, the stress actuator 40 can comprise a pressure chamber in which an operating fluid is present and the predetermined mechanical stress F2 is obtained by pressurizing the operating fluid.

For a better understanding, the mechanical forces F1 mentioned above, corresponding to the interaction forces between the third assembly-die 30 and the punch nose 22, include the mechanical force F3 applied by the third assembly-die 30 on the mobile part. 224 and the mechanical force applied by the third assembly-die 30 on the fixed part 220, during the passage of the punch 20 from the first intermediate position to the extended position.

According to a second variant not shown in the figures, the functional element is constituted by the third assembly-matrix 30. For this purpose, the third assembly-matrix 30 may then comprise a fixed part and a plurality of retractable fingers where each retractable finger is mounted on the fixed part of the third set-die 30 in a manner movable along the longitudinal axis X so as to be able to vary between a deployed position and a retracted position, the third set-die 30 being such that it can delimit : a first forming surface, corresponding to the first spatial impression, having a constant section of cut around the longitudinal axis X when each retractable finger occupies the deployed position, a second forming surface, corresponding to the second spatial impression, having a variable cutting section around the longitudinal axis X when each retractable finger occupies its retracted position, so as to delimit er depressions at each retractable finger in the retracted position where said depressions have complementary spatial shapes of the projecting portions 110 present between the concave deformations 106 of the connecting wall 103 of the container 100 obtained by forming between the punch 20 and the third assembly - matrix 30.

According to a third variant not shown in the figures, the functional element is constituted by the third set-matrix 30. For this purpose, the third set-matrix 30 can then comprise a fixed part and a plurality of fingers. retractable where each retractable finger is mounted on the fixed part of the third die assembly 30 in a manner movable along the longitudinal axis X so as to be able to vary between a retracted position and a deployed position, the third die assembly 30 being such that it can delimit: a first forming surface, corresponding to the first spatial impression, having a constant cross section around the longitudinal axis X when each retractable finger occupies the retracted position, a second forming surface, corresponding to the second spatial imprint, having a variable section of cut around the longitudinal axis X when each retractable finger occupies its deployed position, so as to delimit bumps at the level of each retractable finger in the deployed position, where said bumps have corresponding spatial shapes to the concave deformations 106 of the connecting wall 103 of the container 100 obtained by forming between the punch 20 and the third set-die 30.

According to a particular non-limiting embodiment, with reference to the figures, the third die assembly 30 comprises the central fixed die 31 already mentioned, which is fixed along the longitudinal axis X, and a movable die 32 having an annular shape. delimiting a central opening 33 capable of axially receiving the fixed die 31 and movable along the longitudinal axis X so as to vary between a lowered position (FIG. 10) in which the fixed die 31 is arranged in the movable die 32 and a raised position (Figure 7) in which the mobile die 32 is axially positioned between the fixed die 31 and the punch nose 22.

The movable die 32 is mechanically biased by a return mechanism 50 relative to the fixed die 31 along the longitudinal axis X in a direction urging the movable die 32 towards its raised position, the movable die 32: occupying the raised position (Figure 7) when the punch 20 is positioned between the retracted position and a second intermediate position located between the retracted position and the first intermediate position, and automatically moving from the raised position to the lowered position, as opposed to the action of the return mechanism 50, under the action of displacement of the punch 20 from the second intermediate position to the extended position.

The second intermediate position which the punch 20 can occupy is shown in FIG. 8; this is the position occupied by the punch 20 when it comes into contact with the mobile die 32 when the latter is in the raised position. The movable die 32 occupies a partially lowered position (FIG. 9), axially situated between the lowered position and the raised position, when the punch 20 occupies its first intermediate position.

The displacement marked DI in FIG. 7 symbolizes the displacement of the punch 20 from the retracted position of FIG. 7 to the second intermediate position, that is to say until it comes into contact with the mobile die 32 .

The movement marked D2 in FIG. 8 symbolizes the simultaneous movement of the punch 20 and of the mobile die 32 (the mobile die 32 being driven by the punch 20 in opposition to the action of the return mechanism 50) when the punch 20 passes from the second intermediate position to the first intermediate position. At the end of the movement D2, the mobile die 32 occupies its partially lowered position, which corresponds to the arrangements in FIG. 9.

The movement marked D3 in FIG. 9 symbolizes the simultaneous movement of the punch 20 and of the mobile die 32 (the mobile die 32 being driven by the punch 20 in opposition to the action of the return mechanism 50) when the punch 20 passes from the first intermediate position to the extended position. This leads to the arrangements in Figure 10.

During the movement D3 of the punch 20, which corresponds to the passage from Figure 9 to Figure 10, the retractable fingers 221 move relative to the fixed part 220 of the punch nose 22. This movement of the retractable fingers 221, due to the that the value of the mechanical force F3 becomes greater than the threshold value of the predetermined mechanical stress F2, is symbolized by the arrow D4 in FIG. 9.

FIG. 10 illustrates the situation at the end of the movement D3 of the punch 20, that is to say when it occupies its extended position.

According to a particular non-limiting embodiment, the punch nose 22 and the main body 21 are configured so that in the extended position of the punch 20, the connecting wall 103 of the container 100 obtained by forming between the punch 22 and the third die assembly 30 comprises, between the support ring 104 and the side wall 101, a connecting portion 111 having, seen in any section plane passing through the longitudinal axis X, a section with a rectilinear profile. According to another embodiment, the connecting portion 111 has a variable cross section around the longitudinal axis X.

The installation for the manufacture of aluminum or aluminum alloy containers which has just been described is advantageously simple and economical, has high efficiency and guarantees a high production rate, while being very reliable.

Claims

1. Installation for manufacturing containers (100) of aluminum or aluminum alloy, preferably adapted to contain a beverage, configured so that each container (100) manufactured is formed in one piece and defines a side wall (101 ) cylindrical, a substantially concave bottom wall (102) and a connecting wall (103) connecting the side wall (101) and the bottom wall (102), the side wall (101) having an upper edge opposite the wall bottom (102) allowing the subsequent sealed fixing of a cover to form a closed box, the connecting wall (103) delimiting: a support ring (104) having a convexity oriented on the side opposite to the internal volume (105) delimited by the side wall (101), and a connecting portion (111) between the support ring (104) and the side wall (101), the installation comprising a forming unit adapted to transform a unit cup (500 ) so as to form the bottom wall (102), the a connecting wall (103) and all or part of the side wall (101), the forming unit comprising: a frame (10) defining a passage (11) comprising a longitudinal axis (X), a punch (20) disposed in the passage (11) delimited by the frame (10) movably along the longitudinal axis (X) between a retracted position and an extended position, the punch (20) delimiting a main body (21) and a punch nose (22) located at one end of the main body (21), a first re-stamping die assembly comprising a cup clamp and a re-stamping ring, a second drawing die assembly comprising a plurality of rings of successive draws (for example 3), having decreasing diameters in order to increase the height while reducing the thickness of the side wall, a third die assembly (30) for shaping the bottom wall and the connecting wall, the die assemblies and the punch (20) cooperating together and being configured as one such that, during the passage of the punch from the retracted position to the extended position:

- each unit cup (500) placed between the first set-die and the punch (20) undergoes a reduction in diameter to obtain a re-stamped cup,

- then each re-stamped cup placed between the second die assembly and the punch (20) undergoes stretching to form the side wall and obtain a preform (100 '),

- then each preform (100 ') placed between the third set-die (30) and the punch (20) undergoes shaping of the bottom wall (102) and of the connecting wall (103) of the preform (100 ') to obtain a container (100), the installation being characterized in that a functional element belonging to the group comprising the third die assembly (30) and the punch nose (22) is configured to vary between: a first configuration, automatically adopted when the punch (20) is axially positioned between the retracted position and a first intermediate position located between the retracted position and the extended position, in which the functional element defines a first spatial imprint such that, during the passage of the punch (20) from the retracted position to the first intermediate position, the punch ( 20) and the die sets, including the third die set (30), progressively deform by forming the unit cup (500) in a manner allowing to temporarily form a preform (100 ') whose wall of bottom (102) has the shape of a dome having a constant cross section around the longitudinal axis (X) and whose connecting wall (103) has a constant cross section around the longitudinal axis (X) , a second configuration, automatically adopted when the punch (20) is in the extended position, in which the functional element defines a second spatial imprint such as in the extended position of the punch (20), the connecting wall (103), in particular at the level of the support ring (104) and / or of the connecting portion (111) between the support ring (104) and the side wall (101), of the container (100) obtained by forming between the punch (20) and the third set-die (30) has a variable cutting section around the longitudinal axis (X), the passage from the first configuration to the second configuration being caused automatically by the mechanical forces ( Fl) exerted between the third set- matrix (30) and the nose of poin lesson (22) during the passage of the punch (20) from the first intermediate position to the extended position.

2. Installation according to claim 1, wherein the second spatial imprint delimited by the functional element in the second configuration has a shape complementary to the shape of a constant spatial imprint permanently delimited by the other element than the functional element. from the group comprising the third die assembly (30) and the punch nose (22).

3. Installation according to one of claims 1 or 2, wherein the second spatial footprint delimited by the functional element in the second configuration is such that in the extended position of the punch (20), the connecting wall (103), in particular at the level of the support ring (104) and / or of the connecting portion (111) between the ring support (104) and the side wall (101), of the container (100) obtained by forming between the punch (20) and the third die assembly (30) comprises concave deformations (106), the concavity of which is oriented from the side of the internal volume (105) delimited by the side wall (101) of the container (100), and distributed at regular intervals around the longitudinal axis (X).

4. Installation according to claim 3, wherein the functional element is constituted by the punch nose (22), the punch nose (22) comprising a fixed part (220) integral with the main body (21) and a plurality of retractable fingers (221) where each retractable finger (221) is mounted on the fixed part (220) of the punch nose (22) in a manner movable along the longitudinal axis (X) so as to be able to vary between a deployed position and a retracted position, the punch nose (22) being such that the punch nose (22) delimits: a first forming surface, corresponding to the first spatial impression, having a constant section of cut around the longitudinal axis ( X) when each retractable finger (221) occupies the deployed position, a second forming surface, corresponding to the second spatial impression, having a section of cut variable around the longitudinal axis (X) when each retractable finger (221) occupies its retracted position , so as to delimit depressions (222) at each retractable finger (221) in the retracted position where said depressions (222) have spatial shapes corresponding to the concave deformations (106) of the connecting wall (103) of the container ( 100).

5. Installation according to claim 4, wherein the punch nose comprises a movable part (224) mounted on the fixed part (220) of the punch nose (20) in a movable manner along the longitudinal axis (X), said movable part (224) being made in one piece and delimiting the plurality of retractable fingers (221).

6. Installation according to claim 5, wherein the forming unit comprises at least one biasing actuator (40) exerting a predetermined mechanical bias (F2) of the movable part (224) of the punch nose (22) relative to the fixed part (220) of the punch nose (22) having a threshold value and constraining the movable part (224) of the punch nose (22) in a direction tending to move the retractable fingers (221) to their deployed positions, them retractable fingers (221) being moved towards their retracted positions when the movable part (224) of the punch nose (22) undergoes a mechanical force (F3) along the longitudinal axis (X) oriented in a direction opposite to the direction in which said mechanical stress predetermined (F2) is applied, having a value greater than said threshold value.

7. Installation according to claim 6, wherein the bias actuator (40) comprises a pressure chamber in which an operating fluid is present and the predetermined mechanical stress (F2) is obtained by pressurizing the operating fluid.

8. Installation according to any one of claims 1 to 3, wherein the functional element is constituted by the third assembly-die (30), said third assembly-die (30) comprising a fixed part and a plurality of retractable fingers. wherein each retractable finger is mounted on the fixed part of the third die assembly (30) in a manner movable along the longitudinal axis (X) so as to be able to vary between a deployed position and a retracted position, the third die assembly (30) being such that it delimits: a first forming surface, corresponding to the first spatial impression, having a constant cross section around the longitudinal axis (X) when each retractable finger occupies the deployed position, a second surface of forming, corresponding to the second spatial impression, having a variable section of cut around the longitudinal axis (X) when each retractable finger occupies its retracted position, so as to deli miter depressions at each retractable finger in the retracted position where said depressions have spatial shapes complementary to the protruding portions present between concave deformations (106) of the connecting wall (103) of the container (100).

9. Installation according to any one of claims 1 to 3, wherein the functional element is constituted by the third assembly-die (30), said third assembly-die (30) comprising a fixed part and a plurality of retractable fingers. where each retractable finger is mounted on the fixed part of the third die assembly (30) in a manner movable along the longitudinal axis (X) so as to be able to vary between a retracted position and a deployed position, the third die assembly (30) being such that it defines: a first forming surface, corresponding to the first cavity spatial, having a constant cutting section around the longitudinal axis (X) when each retractable finger occupies the retracted position, a second forming surface, corresponding to the second spatial impression, having a variable cutting section around the axis longitudinal (X) when each retractable finger occupies its deployed position, so as to delimit bumps at the level of each retractable finger in the deployed position, where said bumps have spatial shapes corresponding to the concave deformations (106) of the connecting wall (103) ) of the container (100).

10. Installation according to any one of claims 1 to 9, wherein the third die assembly (30) comprises a fixed die (31) central along the longitudinal axis (X) and a movable die (32) having an annular shape delimiting a central opening (33) capable of accommodating the fixed die (32) and movable along the longitudinal axis (X) so as to vary between a lowered position in which the fixed die (31) is arranged in the movable die (32) and a raised position in which the movable die (32) is axially positioned between the fixed die (31) and the punch nose (22), the movable die (32) being mechanically biased by a mechanism of return (50) relative to the fixed die (31) along the longitudinal axis (X) in a direction urging the movable die (32) towards its raised position, the movable die (32): occupying the raised position when the punch (20) is positioned between the retracted position and a second position intermediate position between the retracted position and the first intermediate position, and moving automatically from the raised position to the lowered position, as opposed to the action of the return mechanism (50), under the movement of the punch (20) from the second intermediate position to the extended position.

11. Installation according to claim 10, wherein the movable die (32) occupies a partially lowered position, axially located between the lowered position and the raised position, when the punch (20) occupies its first intermediate position.