Extrusion machine using a multibelt guide system to engage and guide an extruded profile member against a cooling roller

Abstract

The present invention relates to an extrusion machine (1) comprising a die (2) for producing a profile member (3), a receiving roller (4) for receiving the profile member (3) and conveying it according to a feed movement (FWD), and a guide device (10) that comprises a series of multiple conveying modules (11) which are distributed azimuthally around the central axis (X4) of the receiving roller and which each comprise a first auxiliary roller (14) and a second auxiliary roller (15) carrying a conveyor belt (16) that has, opposite the receiving roller (4), a feedthrough section (16A) which is driven in the direction of the feed movement (FWD) so as to define, together with the surface of the receiving roller (4), a guide path (17) into which the profile member (3) produced by the die (2) is inserted and through which it moves while remaining contained between the receiving roller (4) and the feedthrough section (16A) of the conveyor belt (16).

Description

EXTRUSION MACHINE USING A MULTI-BELT GUIDE SYSTEM TO ENGAGE AND GUIDE AN EXTRUDED PROFILE AGAINST A CHILL ROLLER

[0001] The present invention relates to the field of extrusion machines intended to manufacture profiles, such as strips of elastomeric material intended to be used in the manufacture of pneumatic tires.

[0002] The invention relates more particularly to guiding devices called "clamping devices" which make it possible to guide the profile at the outlet of a die, and in particular which make it possible to engage and place said profile coming from said die on the receiving surface of a cooled roller, on which said profile can cool and stabilize in a controlled manner, that is to say adopt its final shape and dimensions, in contact with said receiving surface, under the effect of the cooling of the elastomer material and the relaxation of the internal stresses which were born from the extrusion process.

[0003] On known extrusion machines, it sometimes happens, particularly at the start of the extrusion process, when the front of the profile begins to emerge from the die while the extrusion machine has not reached a perfectly established regime and therefore potentially presents some deviations in its thermal regulation or some irregularities in the flow of the extruded material(s), that said front of the profile presents certain heterogeneities in its shape and dimensions, such as for example an excess thickness of material forming a frontal bead, or even a certain variability in its mechanical properties or its degree of adhesion known as "tack".

[0004] It also happens, when an extrusion operation is resumed following an emergency stop, that the profile, instead of appearing in the form of a continuous and united block within which the different rubber flows are joined together, appears in the form of a disordered bundle split into several disunited or discontinuous pieces of rubber.

[0005] It is then sometimes difficult to take charge of these different pieces of rubber, and therefore to properly engage the profile on the cooling roller, and more generally in the conveyor circuit which takes charge of said profile downstream of the die.

[0006] In some cases, these situations can cause a blockage, known as "jamming", of the said guide circuit, which requires the machine to be stopped for a cleaning operation. This results in a loss of productivity and a waste of the raw materials used to make the profile.

[0007] To remedy these defects, the applicant has proposed in particular a guide device, described in patent application FR-3 105 064, which uses a chain whose articulated links carry rollers, in order to press the profile against the cooling roller.

[0008] Although such a device is generally satisfactory, it has become apparent that, depending on the composition of the rubbers, it could be somewhat sensitive to fouling, and that fouling could be all the more problematic as cleaning the rollers is in practice quite tedious.

[0009] Furthermore, the inventors have found that the combined action of the circumferential thrust exerted on the profile by the rotation of the chill roll and the free rotation of the chain rollers, which potentially allows said rollers to rotate in either direction, could in certain cases promote a straightening of the profile front, which causes the profile to leave the receiving surface of the chill roll and to return on itself by rolling on a chain roller which folds said profile front upstream, so that the profile front tends to spiral around itself and thus form a bead, which bead tends to grow as it is fed by the material leaving the die. However, such a situation is likely to cause a blockage which requires stopping and cleaning the extrusion installation.

[0010] The objects assigned to the invention therefore aim to remedy the aforementioned drawbacks and to propose an extrusion machine provided with a new improved guiding device which guarantees suitable and reliable conveying of the profiled in all circumstances, particularly during transitional periods of starting or restarting the extrusion machine.

[0011] The objects assigned to the invention are achieved by means of an extrusion machine comprising a die for generating a profile from one or more extruded materials, as well as a receiving roller which has on its circumference a receiving surface centered on a central axis, said receiving roller being mounted in rotation around said central axis so as to make said receiving surface scroll opposite the die, so that said receiving surface can receive the profile which leaves the die and convey said profile in a circumferential advance movement around the central axis, said machine being characterized in that it is provided with a guide device which comprises a succession of several conveying modules which are distributed in azimuth around the central axis, opposite the receiving surface, and which each have: - a drive system which is driven by a drive motor and which comprises at least a first auxiliary roller and a second auxiliary roller which are located at different azimuths around the central axis so that the first auxiliary roller forms an upstream auxiliary roller and the second auxiliary roller forms a downstream auxiliary roller in consideration of the direction of the forward movement, and that the center distance between the first auxiliary roller and the second auxiliary roller covers, in azimuth around the central axis, a predetermined non-zero angular sector, called "elementary angular sector", - a conveyor belt which is carried by said first and second auxiliary rollers so as to present, opposite the receiving surface, a section of said conveyor belt, called the "accompanying section", which is driven by the drive motor in the direction of the forward movement and which covers the elementary angular sector concerned so as to delimit, with the receiving surface, on said elementary angular sector, a guide path in which the profile coming from the die engages and progresses while remaining contained between the receiving surface and the accompanying section of the conveyor belt.

[0012] Advantageously, the guiding device according to the invention makes it possible to discretize the curvature that the profile must follow to fit the receiving roller, by means of a set of successive sections of conveyor belt which are substantially tangent to the receiving surface of the receiving roller, and which actively drive the front of the profile. in the same direction as the desired feed movement, such that said feed movement is imparted by the receiving roller.

[0013] Advantageously, the succession of conveyor belt sections ensures support for the profile which prevents said profile from deviating significantly from the trajectory of the receiving surface, and which on the contrary allows, when necessary, to fold the profile towards said receiving surface. In this respect, the fact that the support sections are driven at a speed whose direction corresponds to the direction of the circumferential speed of the receiving surface allows the profile to converge in the direction of the desired forward movement, and in particular prevents the front of the profile from returning backwards and more particularly from folding back on itself, forming a large bead.

[0014] Furthermore, the conveyor belt sections each provide a conveying surface that is continuous, and therefore impermeable to the material constituting the profile and easy to clean if necessary. Collectively, the successive conveyor belt sections can also be arranged at a very short distance from each other, so as not to provide, at the transition between one conveyor module and the next conveyor module, gaps that would be wide enough to allow the materials constituting the profile to easily escape from the guide path. Thus, the device according to the invention is very little sensitive to fouling, and can moreover be cleaned easily and in a short time whenever necessary.

[0015] Finally, as will be detailed below, the guiding device according to the invention advantageously makes it possible to define a spacing distance between the receiving surface of the receiving roller and the accompanying sections of the conveying modules, and therefore a radial height of the guiding path, which is on the one hand sufficiently narrow so that the conveying modules actively contribute to the embedding, that is to say to the engagement of a profile front on the receiving roller, in transient conditions of starting or restarting an extrusion operation, and on the other hand sufficiently wide so that the conveying modules no longer interfere, in steady conditions, with the profile once said profile is embeded, that is to say once said profile is actually embarked by the receiving roller.

[0016] Other objects, characteristics and advantages of the invention will appear in more detail on reading the description which follows, as well as with the aid of the appended drawings, provided for purely illustrative and non-limiting purposes, among which:

[0017] Figure 1 illustrates, in a simplified view, in a plane normal to the central axis, the handling of a profile by a receiving roller assisted by a guiding device according to the invention.

[0018] Figure 2 is a perspective view of Figure 1.

[0019] Figure 3 illustrates, in an overall perspective view, a part of an extrusion machine according to the invention which is provided with a guiding device corresponding to that whose principle is illustrated in Figures 1 and 2.

[0020] Figure 4 is a detailed perspective view of the guide device implemented within the extrusion machine of Figure 3, and which shows the radially internal face of said guide device, and more particularly the radially internal face of each of the successive accompanying sections belonging to the different conveying modules.

[0021] Figure 5 is a sectional view, in a plane normal to the central axis, of the extrusion machine of Figure 3 and of the guide device placed in the working position, with a detailed view of the interstitial zone located at the transition between two successive accompanying sections.

[0022] Figure 6 illustrates, in a sectional view in the same sectional plane as that of Figure 5, the machine of Figure 3 with this time the guide device moved back into the retracted position, in order to clear access to the receiving surface of the receiving roller and to the internal faces of the conveyor modules.

[0023] Figure 7 is a sectional view, in another plane normal to the central axis, of the machine of Figures 5 and 6, showing a cascade of gears which allows the transmission and synchronization, between the different conveying modules, of the drive movement imparted to the accompanying sections.

[0024] The present invention relates to an extrusion machine 1 which comprises a die 2 for generating a profile 3 from one or more extruded materials.

[0025] Said material(s) are preferably mixtures of elastomers, for example mixtures based on unvulcanized rubber.

[0026] The profile 3 may, for example, be intended to form a tread of a tire, in particular a pneumatic tire, or at least to be part of the composition of such a pneumatic tire.

[0027] For information purposes, profile 3 may have a desired thickness E3, known as “nominal thickness” E3, which will be between 0.3 mm and 40 mm.

[0028] It will be noted in this respect that the extrusion machine 1 according to the invention can be adapted to produce very thin profiles, for example with a thickness E3 of between 0.2 mm and 0.3 mm, which can be used in particular as connecting rubbers, to form interfaces between different layers of a bandage. The machine 1 can also be adapted to generate complex profiles, grouping together several extruded materials of different compositions, intended to form treads and whose thickness E3 can for example be between 6 mm and 20 mm for bandages intended for passenger vehicles, and between 20 mm and 40 mm for bandages intended for heavy goods vehicles.

[0029] In a manner known per se, the die 2, which is here shown schematically in dotted lines in Figures 1 and 5, makes it possible to give the section of said profile 3 the desired shape and dimensions, and where appropriate, when the profile is a complex profile resulting from the assembly of several extruded materials of different compositions, to bring together said extruded materials into a profile 3, by shaping and distributing said materials within the section of said profile.

[0030] The die 2 is connected to an extrusion head (not shown) which comprises at least one channel, and more preferably several channels each connected to an extruder which is responsible for feeding said channel with one of the materials constituting the profile 3. The extruders can be of any suitable type, for example screw extruders, piston extruders, or gear pumps.

[0031] The machine 1 also comprises a receiving roller 4 which has on its circumference a receiving surface 4A centered on a central axis X4.

[0032] Said receiving roller 4 is mounted in rotation around said central axis X4 so as to cause said receiving surface 4A to move opposite the die 2, so that said receiving surface 4A can receive the profile 3 which comes out of the die 2 and convey said profile 3 according to a circumferential FWD advance movement around the central axis X4.

[0033] The extrusion machine 1 advantageously comprises for this purpose a frame 5 provided with bearings 6 which carry the receiving roller 4 and allow the rotation of said receiving roller 4 around its central axis X4.

[0034] The central axis X4 is preferably horizontal, as can be seen in figures 1, 3 and 5, the die 2 then preferably opening at the lowest point of the receiving surface 4A.

[0035] The receiving roller 4 is driven in rotation by a motor 7 called “main motor 7”, preferably an electric motor.

[0036] The receiving roller 4, and more particularly its radially external receiving surface 4A, has a shape of revolution around the central axis X4, preferably a cylindrical shape with a circular base.

[0037] The receiving roller 4 will advantageously form a stabilizing cooling roller, allowing cooling and dimensional stabilization of the profile 3.

[0038] The diameter of the receiving roller 4 is chosen to be sufficient so that its circumference, and more particularly the portion of its circumference which is covered by the profile 3 in steady state, allows, in particular with regard to the linear speed of formation and progression of the profile 3, and therefore with regard to the duration of passage of said profile 3 over the receiving surface 4A, satisfactory cooling and dimensional stabilization of said profile 3.

[0039] For information purposes, the diameter of said receiving roller 4 will preferably be between 15 cm and 300 cm. In practice, it will be possible in particular to use a receiving roller 4 whose diameter is at least equal to 100 cm, preferably equal to or greater than 150 cm, or even equal to or greater than 200 cm.

[0040] The width W4 of the receiving surface 4A, considered along the central axis X4, and therefore transversely to the direction of the forward movement FWD, will preferably be between 50 mm and 1000 mm. For information purposes, for the manufacture of profiles 3 forming treads for passenger vehicles, a receiving surface 4A may be used whose width W4 is between 400 mm and 450 mm, for example equal to 420 mm. For the manufacture of profiles 3 forming treads for heavy goods vehicles, a receiving surface 4A may be used whose width W4 is between 500 mm and 550 mm, for example equal to 520 mm.

[0041] According to the invention, the extrusion machine 1 is provided with a guide device 10 which comprises a succession of several conveying modules 11 which are distributed in azimuth around the central axis X4, opposite the receiving surface 4A, and which each have: - a drive system 12 which is driven by a drive motor 13 (visible in FIG. 3) and which comprises at least a first auxiliary roller 14 and a second auxiliary roller 15 which are located at different azimuths around the central axis so that the first auxiliary roller 14 forms an upstream auxiliary roller and the second auxiliary roller 15 forms a downstream auxiliary roller in consideration of the direction of the advance movement FWD, and that the center distance LU between the first auxiliary roller 14 and the second auxiliary roller 15 covers, in azimuth around the central axis, a predetermined non-zero angular sector Ai l, called “elementary angular sector” Al 1, - a conveyor belt 16 which is carried by said first and second auxiliary rollers 14, 15 so as to present, opposite the receiving surface 4A, a section 16A of said conveyor belt, called the “accompanying section” 16A, which is driven by the drive motor 13 in the direction of the advance movement FWD and which covers the elementary angular sector Al 1 concerned so as to delimit, with the receiving surface 4A, on said elementary angular sector Al 1, a guide path 17 in which the profile 3 coming from the die 2 engages and progresses while remaining contained between the receiving surface 4A and the accompanying section 16A of the conveyor belt 16.

[0042] Advantageously, the plurality of conveying modules 11 makes it possible to guide the profile 3 over several successive elementary angular sectors A11, by a succession of accompanying sections which substantially match the curvature of the surface of receiving surface 4A, at a slight radial distance from said receiving surface 4A. Thus, the plurality of conveyor modules 11 makes it possible to maintain said profile 3 in the immediate vicinity of the receiving surface 4A of the receiving roller 4, to promote the adhesion of said profile 3 to said receiving surface 4A, and thus prevent said profile 3 from detaching from said receiving surface 4A and from deviating from the portion of circular trajectory that it is desired to describe said profile 3 around the central axis X4, in contact with the receiving roller 4.

[0043] It will be noted in this respect that it is preferable to accompany and convey the profile 3 on the receiving surface 4A on a portion of circular trajectory which extends from the exit of the die 2, to the low point of the receiving roller 4, up to, at least, the highest point of the roller 4, diametrically opposite the low point.

[0044] The active movement M16 which is imparted to the accompanying sections 16A by the drive motor 13 and which converges with the advance movement FWD of the receiving surface 4A which results from the rotation of the receiving roller 4, advantageously makes it possible to obtain a swallowing effect according to which the profile 3 is in a way “sucked” into and along the guide path 17 by the receiving surface 4A and the accompanying sections 16A which form movable side walls of said guide path 17. The front of the profile 3 cannot therefore turn back to feed the formation and thickening of a bead.

[0045] Preferably, the axis X14 of the first auxiliary roller 14 and the axis X15 of the second auxiliary roller 15, around which said first and second auxiliary rollers 14, 15 are mounted to rotate on themselves, are parallel to each other and parallel to the central axis X4.

[0046] Preferably, the diameter of the second auxiliary roller 15, forming the downstream roller, is greater than the diameter of the first auxiliary roller 14 forming the upstream roller.

[0047] This makes it possible to refine the upstream part of the guide device 10, in order to facilitate the insertion of said guide device 10, in the form of a point, close to the outlet of the die 2, as can be seen in Figures 3 and 5, in an area of ​​the machine 1 which is particularly congested, in particular due to the presence of the extrusion head and several extruders.

[0048] This also makes it possible to use, according to a preferred characteristic, the second auxiliary roller 15, that is to say the downstream auxiliary roller of each conveying module 11, as a motorized auxiliary roller, which receives the movement of the drive motor 13 and transmits this movement to the accompanying section 16A. Thus, within each conveying module 11, said accompanying section 16A is advantageously pulled downstream, in the direction of the FWD advance movement, by the second auxiliary roller 15.

[0049] The width W16 of the conveyor belt 16, and therefore more particularly the width W16 of the accompanying section 16A, considered along the central axis X4, and therefore transversely, here perpendicularly, to the direction of the advance movement FWD, preferably represents between 40% and 80%, for example 70%, of the width W4 of the receiving surface 4A.

[0050] For information purposes, the width W16 of the conveyor belt 16, and more particularly the width of the accompanying section 16A, is preferably between 100 mm and 800 mm, for example between 100 mm and 500 mm, and may in particular be equal to 280 mm or 420 mm.

[0051] Preferably, the accompanying section 16A of at least one conveyor module 11, and more preferably each accompanying section 16A of several conveyor modules 11 or even more preferably of all the conveyor modules 11, will form a taut strand of the conveyor belt 16, taut between the first auxiliary roller 14 and the second auxiliary roller 15, and which therefore extends rectilinearly from the first auxiliary roller 14 to the second auxiliary roller 15, in a plane which is parallel to the central axis X4.

[0052] In this preferred configuration, the succession of accompanying sections 16A forms, in a plane normal to the central axis X4, a succession of straight line segments which thus constitute as a whole a sort of broken line which substantially follows the curvature of the receiving surface 4A, at a radial distance from said receiving surface 4A, as is notably visible in Figure 1. In three dimensions, the accompanying sections 16A will thus form a succession of plane facets which substantially follow, by discretizing it, the cylindrical surface with a circular base of the receiving roller 4.

[0053] Particularly preferably, several of the conveyor modules 11, and preferably all of the conveyor modules 11, are arranged in such a way that, in a plane normal to the central axis X4, the straight line segment formed by the accompanying section 16A is oriented in such a way that the mediator of said straight line segment forms, with the ray which comes from the central axis X4 and which intersects said mediator in the middle of said straight line segment, an angle less than or equal to 10 degrees, preferably less than or equal to 5 degrees, and more preferably a zero angle, as can be seen in Figure 1. A zero angle means that the mediator of the straight line segment merges with a ray coming from the central axis X14 and therefore passes through said central axis X14.

[0054] Thus, each accompanying section 16A will preferably extend substantially parallel (at + / - 10 degrees, or even at + / - 5 degrees) or even exactly parallel (at + / - zero degrees) to the straight line which is tangent to the arc of a circle which is defined, on the circumference of the receiving roller 4, by the elementary angular sector Ai l, at the midpoint of said arc of a circle, that is to say substantially parallel or even exactly parallel to the straight line which is tangent to the point of intersection of said arc of a circle with the bisector of said elementary angular sector.

[0055] The outline of the guide path 17 thus formed by the accompanying sections 16A will therefore fairly faithfully follow the curvature of the receiving surface 4A, while maintaining a radial distance, and therefore a height H17 of the passage path 17, well controlled in relation to said receiving surface 4A.

[0056] It will be possible to provide, within the conveyor module 11, and as can be seen in figures 5 and 6, a flat support sole 18, on which the back of the accompanying section 16A slides, and which thus contributes to supporting said accompanying section 16A against the forces exerted by the profile 3.

[0057] Preferably, the consecutive accompanying sections 16 will be almost contiguous, that is to say that the clearance gaps 20 which it is necessary to provide between accompanying sections 16A to avoid interference between neighboring conveyor modules 11, and more particularly between neighboring accompanying sections 16A, will have a size sufficiently narrow to prevent the passage of the profile 3 through said clearance gaps 20.

[0058] In this respect, it will be noted that, preferably, the interstitial distance d20 which separates an accompanying section 16A belonging to a conveying module 11 from the accompanying section 16A belonging to the following conveying module 11, as can be seen in FIG. 5, is strictly less than the nominal thickness of the profile E3.

[0059] Preferably, the interstitial distance d20 is between 2 mm and 5 mm, more preferably less than or equal to 3 mm.

[0060] It will also be noted that, according to a preferred characteristic which may constitute an invention in its own right, the machine 1 comprises at least one sensor, and preferably several sensors, for example at least one temperature sensor and / or at least one thickness sensor, which are intended to measure one or more properties of the profile 3 engaged in the guide path 17, for example the temperature and / or the thickness of said profile 3, and said sensor(s) are arranged in at least one clearance gap 20 which separates an accompanying section 16A from the accompanying section 16A immediately following.

[0061] It will thus be possible to advantageously house said sensor(s) as close as possible to the outlet of the die 2, and consequently improve the regulation of the extrusion, as well as the management of the rotation of the receiving roller 4 and the drive speed of the accompanying sections 16 A.

[0062] In particular, it will be possible to house in a clearance gap 20 at least one sensor, and preferably two sensors, from among: - a pyrometer, making it possible to measure the temperature of the profile 3, here more particularly the temperature of the radially external surface of the profile 3, - a profilometer for measuring the thickness of the profile 3, i.e. the radial height of said profile 3 relative to the receiving surface 4A, and this preferably at several points distributed axially over the width of the profile 3.

[0063] In absolute terms, it could be envisaged that a single conveyor belt 16 runs in one piece through several consecutive conveyor modules 11, or even through all of the conveyor modules 11, so that the different accompanying sections 16A would belong to said same conveyor belt 16.

[0064] For this purpose, it would be possible, for example, to provide return rollers between successive conveyor modules 11, which return rollers would be located at the azimuth of the clearance gaps 20, and radially further from the central axis X4 than the auxiliary rollers 14, 15, so that said return rollers can, on the one hand, receive the conveyor belt 16 which is deflected radially outwards, away from the receiving surface 4A, by the downstream auxiliary roller 15 of a conveyor module 11, at the outlet of an accompanying section 16A, then, on the other hand, subsequently return said conveyor belt 16 to the receiving surface 4A, so that it is taken up by the upstream auxiliary roller 14 of the following conveyor module 11, and can form the following accompanying section 16A, suitably reoriented relative to the accompanying section 16A. previous in order to follow, here to tangent,the curvature of the receiving surface 4A.,

[0065] However, preferably, each conveyor module 11 has its own conveyor belt 16, distinct from the conveyor belts 16 of the other conveyor modules 11, as can be seen in particular in FIG. 1.

[0066] Such an arrangement makes it possible in particular to simplify the structure of the conveyor modules 11, and facilitates the operations of cleaning or replacing the conveyor belts 16.

[0067] Such an arrangement also makes it possible to easily adapt the azimuthal extent of the arc covered by the guidance device 10 around the central axis X4, by easily adding or removing on demand one or more conveyor modules 11, and therefore one or more accompanying sections 16 A, without disturbing the arrangement or the adjustment of the conveyor modules 11 present.

[0068] Each of the conveyor belts 16 will advantageously form a loop which runs in a closed circuit within the conveyor module 11 which is specific to it, passing around the first auxiliary roller 14 and the second auxiliary roller 15 of said conveyor module 11.

[0069] The conveyor belt 16 will then have a forward strand, forming a taut strand, which starts from the first upstream auxiliary roller 14 to join the second downstream auxiliary roller 15, and which forms the accompanying section 16A, then a return strand, forming a soft strand, located behind the guide path 17, and which starts from the second auxiliary roller 15 downstream to return to the first auxiliary roller 14 upstream.

[0070] More preferably, each conveyor belt 16 will pass exclusively around the first auxiliary roller 14 and the second auxiliary roller 15 of its conveyor module 11, to the exclusion of other return rollers, which will provide a particularly simple, compact, light and reliable circulation path, which is limited to the aforementioned taut forward strand and the slack return strand.

[0071] The adjustment of the tension of the conveyor belt 16 may be carried out by means of any suitable tensioning system, for example a tensioning system making it possible to adjust the position of the axis X14 of the first auxiliary roller 14 relative to the support sole 18, and therefore relative to the axis XI 5 of the second auxiliary roller 15, the position of which is preferably fixed relative to said support sole 18.

[0072] The conveyor belt(s) 16 may be made of any suitable material, and in particular of any material which is on the one hand sufficiently flexible to be engaged without suffering damage on the auxiliary rollers 14, 15, and on the other hand compatible with the temperatures at which the profile 3 is used. For example, the conveyor belt(s) 16 may be formed from a polyester and cotton-based fabric.

[0073] In absolute terms, it would be possible to envisage equipping each conveyor module 11 with a drive motor 13 which would be specific to said conveyor module 11, and carried by said conveyor module 11. The guidance device 10 could thus comprise several drive motors 13, and more particularly as many drive motors 13 as there are conveyor modules 11.

[0074] However, preferably, the guiding device 10 comprises a drive motor 13 which is common to the different conveying modules 11, as well as a transmission mechanism 21 which connects said drive motor 13 to the respective drive systems 12 of said different conveying modules 13.

[0075] By using a single drive motor 13, preferably an electric motor, for all of the conveyor modules 11, it is advantageous to produce a relatively simple, space-saving and energy-saving guide device 10. In particular, it is thus advantageous to offset the drive motor 13 upwards, relative to the lower part of the receiving roller 4 and the guide device 10, into a space which is relatively clear, and in particular which is much less cluttered than the lower zone of the machine 1 which is occupied in particular by the extruders.

[0076] Furthermore, the guidance device 10 preferably comprises a synchronization system 22 which makes it possible to synchronize the speeds of the accompanying sections 16A of the different conveying modules 11 with each other.

[0077] More preferably, said synchronization system 22 makes it possible to synchronize on the one hand the movement speeds M16 of the accompanying sections 16A with each other, and on the other hand said movement speeds M16 of the accompanying sections 16A with the rotation speed of the receiving roller 4, according to a chosen synchronization ratio.

[0078] The synchronization system 22 may in particular comprise a control unit, for example an electronic control unit, capable of controlling the main motor 7 of the receiving roller 4 and the drive motor(s) 13 of the conveyor modules 11.

[0079] Preferably, as can be seen in Figures 3 and 7, the guide device 10 comprises a cascade of gears 23 which connects together auxiliary rollers 15 of the successive conveyor modules 11, here more preferably the second auxiliary rollers 15 belonging to the successive conveyor modules 11, so as to ensure, step by step, a synchronous drive of said auxiliary rollers 15 and therefore of the accompanying sections 16A belonging to said successive conveyor modules 11.

[0080] The gear cascade 23 can thus advantageously form both a part of the transmission mechanism 21 and a mechanical part of the synchronization system 22.

[0081] Said cascade of gears 23 may be coupled to the drive motor 13 by any suitable coupling member, for example by means of a dog clutch.

[0082] Advantageously, the gear cascade 23 is very robust and does not require lubrication, which makes its operation particularly clean and in particular unlikely to pollute the profile 3.

[0083] Furthermore, the toothed wheels constituting the gear cascade 23 are advantageously carried by the conveyor modules 11. In this way, maintenance operations are facilitated, since it is easy to remove a conveyor module 11, carrying its own portion of the gear cascade 23, and to replace it with another conveyor module, which also carries its own portion of the gear cascade 23 and which is therefore integrated into the gear cascade 23 in place in the device 10 without it being necessary to carry out specific adjustments or any modifications to said device 10.

[0084] Preferably, each second auxiliary roller 15 will be mounted on a shaft rotatably mounted on the conveyor module 11 and to which a toothed wheel belonging to the gear cascade 23 is fixed.

[0085] Preferably, the accompanying sections 16A defined by the conveying modules 11 are distributed around the central axis X4 so as to cover a zone called the “accompanying zone” which extends from the outlet of the die 2, forming an upstream limit, to a downstream limit which is located at an azimuth of between 90 degrees and 270 degrees, preferably between 120 degrees and 200 degrees, more preferably between 130 degrees and 180 degrees, counted from the outlet of the die 2 and in the direction of the FWD advance movement.

[0086] Thus, the guiding device 10 ensures support over at least a quarter turn, preferably over approximately a half turn around the receiving roller 4, and therefore allows good grip of the profile 3 on the receiving surface 4A.

[0087] As indicated above, the extent of the accompanying zone may be adjusted by adding or removing one or more conveyor modules 11.

[0088] Preferably, the guide device 10 comprises at least three consecutive conveyor modules 11, preferably at least four conveyor modules. consecutive, more preferably between four and eight consecutive conveyor modules 11, for example five consecutive conveyor modules 11.

[0089] The number of conveyor modules 11 is thus sufficiently high so that said conveyor modules 11 suitably match the curvature of the receiving surface 4A, and contain the profile 3 at a short distance from said receiving surface 4A, while being sufficiently moderate so as not to unduly multiply the conveyor modules 11, which could be detrimental to the simplicity, robustness and cost of the guide device 10.

[0090] Preferably, several of the conveyor modules 11, and preferably all of the conveyor modules 11, are identical to each other, and in particular use the same first auxiliary rollers 14, the same second auxiliary rollers 15, the same gears, the same support soles 18, the same conveyor belts 16, which makes it possible to produce and maintain the guide device 10 by means of standardized parts.

[0091] If applicable, only the conveyor module 11 which carries the common drive motor 13 has, compared to the other conveyor modules 11, a specific coupling mechanism which forms a part of the transmission mechanism 21 and which ensures the connection of the shaft of said drive motor 13 to said transmission mechanism 21, here to the gear cascade 23. Advantageously, this coupling mechanism is adaptable to any conveyor module 11, so that it is easy, and reversibly, to convert a standard conveyor module 11, called "passive", that is to say without a drive motor 13, into a conveyor module 11 called "motor", equipped with a drive motor 13, or vice versa, to transform a motor conveyor module 11 into a passive conveyor module 11.

[0092] Preferably, the elementary angular sector Ai l of each conveying module 11 is between 20 degrees, low value, and 30 degrees, high value, for example between 24 degrees and 25 degrees.

[0093] Here again, the low value allows each conveyor module 11 to guarantee sufficient individual coverage, which makes it possible to limit the number of conveyor modules 11 necessary to cover the desired support area, and therefore to limit the complexity of the guidance device 10, while the high value makes it possible to maintain a splitting of the guidance device 10 which is sufficient to adapt the orientations of the successive accompanying sections 16A according to a discretization step which is sufficiently fine to substantially follow the curvature of the receiving surface 4A, and thus avoid excessive variations in the radial height H17 of the guide path 17.

[0094] For information purposes, the arrangement of the conveyor modules 11, and more particularly the extent of the elementary angular sector Ai l, will be such that the difference between, on the one hand, the smallest radial height H17 of the guide path 17 defined by an accompanying section 16A, and therefore more generally a conveyor module 11, relative to the receiving surface 4A, and, on the other hand, the largest radial height H17 of said guide path 17 defined by this same accompanying section 16A, and more generally by this same conveyor module 11, relative to the receiving surface 4A, will be less than or equal to 15 mm, more preferably less than or equal to 10 mm.

[0095] Preferably, as is clearly visible in Figures 3, 4, 5 and 6, the conveying modules 11 are carried by a support 30 which is mounted to move relative to the frame 5 by means of a positioning mechanism 31 which makes it possible to adjust the distance of the support 30, and consequently the distance of the different accompanying sections 16A, relative to the receiving surface 4A.

[0096] Thus, the positioning mechanism 31 makes it possible to alternately place the support 30, and therefore all of the conveying modules 11 and their respective accompanying sections 16A, in at least one working position, close to the receiving surface 4A, as illustrated in FIG. 5, and at least one withdrawal position, illustrated in FIG. 6, which is further from the central axis X14 and the receiving surface 4A than the working position.

[0097] Advantageously, there is at least one retracted position which allows in particular an operator to access the receiving surface 4A and the accompanying sections 16A for cleaning or maintenance operations.

[0098] The working position will be chosen so that the distance which separates the conveyor modules 11, and more particularly the accompanying sections 16 A, from the receiving surface 4A of the receiving roller 4 is such that the sections accompanying sections 16A can, at least during the transient phases of starting or restarting the extrusion operation, catch the profile 3 if said profile 3 does not adhere properly to the receiving surface 4A or becomes detached from it, and force said profile 3 to advance according to the planned FWD advance movement and to return towards and against the receiving surface 4A, so that said accompanying sections 16A can provide assistance in the locking of said profile 3.

[0099] If necessary, the positioning mechanism 31 will make it possible to adapt the working position, and in particular to select the appropriate working position from among several possible distinct working positions, depending on the nominal thickness E3 of the profile 3 to be produced.

[0100] As will be seen below, the positioning mechanism 31 will preferably make it possible to place the support 30, and therefore the conveying modules 11 and their respective accompanying sections 16A, in a working position which is such that the accompanying sections 16A are able to punctually take charge of the profile 3, when the profile deviates from the desired trajectory, during the transient start-up phases, but on the other hand no longer interfere with the profile 3 in steady state, when said profile 3 adheres properly to the receiving surface 4A and progresses according to the planned FWD advance movement.

[0101] The positioning mechanism 31 may comprise rails 32 which guide in translation the movements towards and away from the support 30, here in rectilinear translation, relative to the frame 5.

[0102] As can be seen in particular in Figures 3, 5 and 6, said rails 32 can be inclined relative to the horizontal, according to an upward slope in the direction of distance, here a slope of approximately 15 degrees, so as to allow the support 30 and the conveying modules 11 to move, and more particularly alternately to move forward to position themselves near the outlet of the die 2 then to move backward to extract themselves from the area close to the die 2, without interfering with the rest of the machine 1, in particular without interfering with the extrusion head or the extruders located vertically above the guide device 10.

[0103] The support 30, which preferably holds the conveyor modules 11 in a fixed position relative to each other, can be formed for example by a mechanically welded frame, which is both rigid and light.

[0104] Preferably, the positioning mechanism 31 has an elastic suspension member 33, such as a pneumatic cylinder 34, which allows the support 30, and therefore the conveying modules 11, to move back elastically under the thrust of the profile 3.

[0105] Such an arrangement advantageously allows the support 30, once it is placed in the working position, to move back slightly and temporarily, if necessary, to allow the passage of a bead of material forming an excess thickness on the front edge of the profile 3. This avoids causing jamming, or even damage to the guide device 10.

[0106] Advantageously, once the excess thickness of the profile 3 has passed, the support 30 automatically returns to its nominal working position, by simple elastic return, in order to be able to guide the rest of the profile 3 as close as possible to the receiving surface 4A.

[0107] Preferably, the elastic suspension member 33 is formed by at least one pneumatic cylinder 34 which is also part of the positioning mechanism 31 and which serves to position the support 30 relative to the receiving roller 4, and therefore more particularly to move the support 30 between its working position and its retracted position and vice versa.

[0108] The compressibility of the air contained in said pneumatic cylinder 34 will then be advantageously used to obtain the elastic effect and stiffness sought to achieve the elastic recoil of the support 30 under the thrust of the profile 3.

[0109] Preferably, the minimum distance which separates, in the working position, each accompanying section 16A from the receiving surface 4A, and which therefore defines the smallest radial height H17 of the corresponding guide path 17, is strictly greater than the nominal thickness E3 of the profile 3, preferably between 1.5 times and 2.5 times the nominal thickness E3 of the profile.

[0110] For information purposes, the minimum distance which separates each accompanying section 16A from the reception surface 4A, and which therefore defines the smallest radial height HI 7 of the corresponding guide path 17, may be for example between 20 mm and 60 mm, in particular be equal to 20 mm or equal to 40 mm.

[0111] According to a preferred characteristic which may constitute an invention in its own right, this makes it possible to place the accompanying sections 16A on the one hand sufficiently close to the receiving surface 4A so that, in transient conditions, a bead or a split or disordered front edge of a profile 3 comes into contact with said accompanying sections 16A, and can therefore be redirected towards and against the receiving surface 4A by said accompanying sections 16A, driven by their movement M16 directed downstream, and on the other hand sufficiently far from the receiving surface 4A so that, in steady conditions, the profile 3 which adheres to the receiving surface 4A and has a thickness equal to its nominal thickness E3 no longer touches the accompanying sections 16A.In this case, the drive motor 13, and therefore the accompanying sections 16 A, can advantageously be deactivated and stopped in steady state, to save energy, without creating friction or other unnecessary loads which would hinder the rotation of the receiving roller 4 and the progression of the profile 3.

[0112] In other words, the guide device 10 can thus advantageously, while remaining in the same predefined working position both in transient mode and in steady mode, be selectively activated during the transient phases in order to help the nascent profile 3 to engage and wind onto the receiving surface 4A, then deactivated in steady mode, in order to allow the profile 3 which is glued to the receiving surface 4A to circulate freely in the guide path 17, with the necessary clearance relative to the accompanying sections 16A.

[0113] Advantageously, the support 30 can thus remain in the same working position throughout the extrusion operation, both at the start thereof and in steady state, and only be moved to the retracted position when a cleaning operation or a change of tooling, in particular a change of die 2, becomes necessary.

[0114] It will be noted that the smallest radial height H17 of the guide path 17 is located here in practice at the level of the middle of the straight line segment formed, in a plane normal to the central axis X4, by the accompanying section 16 A.

[0115] Furthermore, according to a preferred characteristic which may constitute an invention in its own right, the extrusion machine 1 comprises a protective blade 40, distinct from the die 2, which protective blade 40 is fixed to the frame 5 opposite the receiving surface 4A, downstream of the outlet of the die 2 and upstream of the upstream auxiliary roller 14 of the first of the conveying modules 11, in order to define an air gap 41 which is intended to limit the radial swelling of the profile 3 and the thrust forces exerted by the profile 3 which leaves the die 2, before said profile 3 reaches the first of the conveying modules 11.

[0116] Thus, the protective blade 40, which is fixed relative to the frame 5, in particular absorbs the forces resulting from the swelling of the profile 3 which occurs when said profile 3 leaves the die 2 and is exposed to the open air. The protective blade 40 thus carries out, as it were, a second calibration of the profile 3, which follows the first calibration carried out by the die 2 itself. The protective blade 40 thus protects the first conveyor module 11 and the structure of the support 30, which is relatively thin and therefore potentially fragile and vulnerable in this area, from any excessive pressure.

[0117] More particularly, the protective blade 40 forces the profile 3 emerging from the die 2 to pass into the air gap 41, and thus to engage in the guide path 17 by passing “above” the first auxiliary roller 14 of the first conveying module 11, that is to say by passing between said first auxiliary roller 14 and the receiving surface 4A, without the profile 3 coming into frontal contact with said first auxiliary roller 14, and therefore without said profile 3 coming into force a strong thrust on the upstream tip of the first conveying module 11 forming the upstream tip of the guide device 10, it being considered that such a strong thrust could otherwise cause a destructive bending of said upstream tip of the guide device 10.

[0118] Furthermore, the protective blade 40 also advantageously makes it possible to slightly roll the front of the profile 3 on itself and thus to fold the front of the profile 3 on itself to form a slight excess thickness at the level of the front of the profile, excess thickness which will initially facilitate the handling and guiding of the front of the profile 3 by the guide device 10, along the circumference of the receiving roller 4, then which will, in a second stage, when the front of the profile has traveled the necessary distance on the receiving surface 4A, facilitate the detachment of the profile 3 and the transfer of said profile 3 from the receiving surface 4A of the receiving roller 4 to a transport circuit located downstream of the receiving roller 4.

[0119] Of course, the invention is in no way limited to the embodiment variants described above, the person skilled in the art being able in particular to isolate or freely combine one or other of the aforementioned characteristics, or to substitute equivalents for them.

Claims

CLAIMS 1. Extrusion machine (1) comprising a die (2) for generating a profile (3) from one or more extruded materials, as well as a receiving roller (4) which has on its circumference a receiving surface (4A) centered on a central axis (X4), said receiving roller (4) being mounted in rotation about said central axis (X4) so ​​as to cause said receiving surface (4A) to move opposite the die (2), so that said receiving surface (4A) can receive the profile (3) which leaves the die (2) and convey said profile (3) according to a circumferential advance movement (FWD) about the central axis (X4), said machine (1) being characterized in that it is provided with a guide device (10) which comprises a succession of several conveying modules (11) which are distributed in azimuth about the central axis (X4), opposite the surface reception (4A), and which each present: - a drive system (12) which is driven by a drive motor (13) and which comprises at least a first auxiliary roller (14) and a second auxiliary roller (15) which are located at different azimuths around the central axis (X4) so ​​that the first auxiliary roller (14) forms an upstream auxiliary roller and the second auxiliary roller (15) forms a downstream auxiliary roller in consideration of the direction of the forward movement (FWD), and that the center distance (LU) between the first auxiliary roller (14) and the second auxiliary roller (15) covers, in azimuth around the central axis (X4), a predetermined non-zero angular sector (Al 1), called “elementary angular sector” (Al 1), - a conveyor belt (16) which is carried by said first and second auxiliary rollers (14, 15) so as to present, opposite the receiving surface (4A), a section (16A) of said conveyor belt (16), called the "accompanying section" (16A), which is driven by the drive motor (13) in the direction of the forward movement (FWD) and which covers the elementary angular sector (Ai l) concerned so as to delimit, with the receiving surface (4A), on said elementary angular sector (Ai l), a guide path (17) in which the profile (3) coming from the die (2) engages and progresses while remaining contained between the receiving surface (4 A) and the accompanying section (16A) of the conveyor belt 2. Machine according to claim 1 characterized in that each conveyor module (11) has its own conveyor belt (16), separate from the conveyor belts (16) of the other conveyor modules (11).

3. Machine according to claim 1 or 2 characterized in that the guide device (10) comprises a drive motor (13) which is common to the different conveying modules (11), as well as a transmission mechanism (21) which connects said drive motor (13) to the respective drive systems (12) of said different conveying modules (11).

4. Machine according to one of the preceding claims, characterized in that the guide device (10) comprises a synchronization system (22) which makes it possible to synchronize the speeds of the accompanying sections (16A) of the different conveying modules (11).

5. Machine according to claim 3 or 4 characterized in that the guide device (10) comprises a cascade of gears (23) which connects together auxiliary rollers (15) of the successive conveyor modules (11), so as to ensure, step by step, synchronous driving of said auxiliary rollers (15) and therefore of the accompanying sections (16A) belonging to said successive conveyor modules (11).

6. Machine according to one of the preceding claims, characterized in that the accompanying sections (16A) defined by the conveying modules (11) are distributed around the central axis (X4) in a zone called the "accompanying zone" which extends from the outlet of the die (2), forming an upstream limit, to a downstream limit which is located at an azimuth of between 90 degrees and 270 degrees, preferably between 120 degrees and 200 degrees, more preferably between 130 degrees and 180 degrees, counted from the outlet of the die (2) and in the direction of the feed movement (FWD).

7. Machine according to one of the preceding claims, characterized in that the guide device (10) comprises at least three consecutive conveying modules (11), preferably at least four consecutive conveyor modules (11), more preferably between four and eight consecutive conveyor modules (11), for example five consecutive conveyor modules (11).

8. Machine according to one of the preceding claims, characterized in that the elementary angular sector (Ai l) of each conveying module (11) is between 20 degrees and 30 degrees, for example between 24 degrees and 25 degrees.

9. Machine according to one of the preceding claims, characterized in that the interstitial distance (d20) which separates an accompanying section (16A) belonging to a conveying module (11) from the accompanying section (16A) belonging to the following conveying module (11) is strictly less than the nominal thickness (E3) of the profile, and / or preferably between 2 mm and 5 mm, more preferably less than or equal to 3 mm.

10. Machine according to one of the preceding claims, characterized in that it comprises a frame (5) provided with bearings (6) which carry the receiving roller (4) and allow the rotation of said receiving roller (4) around its central axis (X4), and in that the conveying modules (11) are carried by a support (30) which is mounted to move relative to said frame (5) by means of a positioning mechanism (31) which makes it possible to adjust the distance of the support (30), and consequently the distance of the different accompanying sections (16A), relative to the receiving surface (4A).

11. Machine according to claim 10 characterized in that the positioning mechanism (31) has an elastic suspension member (33), such as a pneumatic cylinder (34), which allows the support (30), and therefore the conveying modules (11), to move back elastically under the thrust of the profile (3).

12. Machine according to one of the preceding claims, characterized in that the minimum distance which separates each accompanying section (16A) from the receiving surface (4A), and which therefore defines the smallest radial height (H17) of the guide path (17) corresponding, is strictly greater than the nominal thickness (E3) of the profile, preferably between 1.5 times and 2.5 times the nominal thickness (E3) of the profile.

13. Machine according to one of the preceding claims, characterized in that it comprises a frame (5) provided with bearings (6) which carry the receiving roller (4) and allow the rotation of said receiving roller (4) around its central axis (X4), and in that it comprises a protective blade (40), separate from the die (2), which protective blade (40) is fixed to the frame (5) opposite the receiving surface (4A), downstream of the outlet of the die (2) and upstream of the auxiliary roller (14) upstream of the first of the conveying modules (11), in order to define an air gap (41) which is intended to limit the radial swelling of the profile (3) and the thrust forces exerted by the profile (3) which leaves the die (2), before said profile (3) reaches the first of the conveying modules (11).

14. Machine according to one of the preceding claims, characterized in that it comprises at least one sensor, and preferably several sensors, for example at least one temperature sensor and / or at least one thickness sensor, which are intended to measure one or more properties of the profile (3) engaged in the guide path (17), for example the temperature and / or the thickness of said profile (3), and in that said sensor(s) are arranged in at least one clearance gap (20) which separates an accompanying section (16A) from the immediately following accompanying section (16A).

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