WO2017168225A1

WO2017168225A1 - Machine for the continuous production of a corrugated tube

Info

Publication number: WO2017168225A1
Application number: PCT/IB2016/057615
Authority: WO
Inventors: Bruno Galli
Original assignee: Itib Machinery International Srl
Current assignee: Itib Machinery International Srl
Priority date: 2016-03-29
Filing date: 2016-12-14
Publication date: 2017-10-05
Anticipated expiration: 2018-09-29
Also published as: ITUA20162083A1

Abstract

A machine (1) for the continuous production of a corrugated tube comprises a kinematic head device (20) for the movement of the mould groups (S). Said kinematic head device (20) comprises a toothed input wheel (30) and a toothed output wheel (32) kinematically engaged with the input wheel (30), e.g. by a toothed transmission wheel (34) that transfers the motion from the input wheel (30) to the output wheel (32).

Description

DESCRIPTION

"MACHINE FOR THE CONTINUOUS PRODUCTION OF A CORRUGATED

TUBE "

[0001] This invention relates to the field of machines for the continuous production of corrugated tubes made of plastic material.

[0002] These machines are equipped with two groups of moulds, movable along two side by side annular paths. Each mould is provided with an open cavity that constitutes a half-imprint for the realisation of a section of the corrugated tube. In the area between the two paths, along a predefined section, the moulds of the first group face moulds of the second group, so that the cavity of the first and the cavity of the second mate and realise the complete imprint.

[0003] Plastic material is injected into the imprint, is distributed on the walls of the imprint and realises the section of corrugated tube.

[0004] At the end of the coupling section, the two moulds are separated and release the section of formed tube. The continuous movement of the moulds in succession along the coupling section ensures the formation of sections of corrugated tube in succession, which together realise the tube in its entirety.

[0005] At the end of the coupling section, the moulds now decoupled start off on a respective return section of the annular path, to move back to the beginning of the coupling section.

[0006] There are numerous embodiments of machines for the continuous production of corrugated tubes. A traditional solution is illustrated, for example, in document DE 3810915C1.

[0007] The market requires corrugated tubes in many different diameters, from small (typically, up to 125 millimetres), to medium-small (up to 250 millimetres), medium-large (up to 600 millimetres), and large (up to 1500 millimetres) .

[0008] In machines for the production of large sized corrugated tubes, the translation speeds of the moulds along the coupling section of the annular path is very low (in general, not exceeding 0.2 to 0.5 metres/minute for diameters of 1500 millimetres) and the return travel of the mould is performed by means of suitable kinematic mechanisms and gears, which allow making the moulds travel along the return section one after another ("shuttle type") .

[0009] These machines are obviously very complex and costly .

[0010] In machines for the production of small and medium corrugated tubes, the speeds are significantly higher: up to 25 metres /minute for the first, up to 15 metres /minute for medium-small and up to 4 metres /minute for medium- large .

[0011] In these machines, the moulds in the head and tail of the coupling section are engaged with appropriate kinematic mechanisms that ensure their movement, while all the other moulds are pushed by those being gripped.

[0012] The industry trend, justified by the need to obtain high production volumes and amortise the cost of these machines, is to work at increasingly higher speeds.

[0013] This fact creates significant problems for the machines described above.

[0014] In fact, the actions that develop between mould and mould along the annular path are particularly intense and variable along the way, causing increase mould wear (fatigue stress and pitching) , with consequences for the functionality of the machine.

[0015] The purpose of this invention is to meet the above needs and overcome the problems mentioned with reference to the prior art.

[0016] This purpose is achieved by a machine for the production of continuous corrugated tube realised according to claim 1. The dependent claims identify further embodiments.

[0017] The characteristics and the advantages of the machine according to this invention will be apparent from the following description, given by way of non-limiting example, in accordance with the accompanying figures, in which :

[0018] - Figure 1 is a layout of a machine for the continuous production of corrugated tube, according to an embodiment of this invention;

[0019] - Figure 2 shows a schematic layout of the machine of Figure 1;

[0020] - Figures 3, 4 and 5 illustrate a schematic layout of a head zone of the machine, according to an embodiment of this invention, in successive moments of the movement of a mould group;

[0021] - Figure 6 represents a mould-holder carriage of a mould group, according to an embodiment;

[0022] - Figure 7 illustrates a mould group comprising the mould-holder carriage of Figure 6;

[0023] - Figure 8 shows a schematic layout of a head zone of the machine, which highlights the guide grooves that define the path of the mould groups;

[0024] - Figure 9 represents a schematic layout of a head zone of the machine;

[0025] - Figure 10 is a section view of the of the head zone of Figure 9, along the section plane X-X of Figure [0026] - Figure 11 shows an axonometric view of actuation means of the machine, according to a preferred embodiment ;

[0027] - Figure 12 represents transfer means of the machine, according to a preferred embodiment;

[0028] - Figure 13 illustrates a schematic layout of a machine head zone according to a further embodiment of this invention;

[0029] - Figure 14 is a sectional view of the plane of section XIV in Figure 13;

[0030] - Figure 15 is a sectional view of the plane of section XIV in Figure 13.

[0031] According to this disclosure, a machine 1 for the continuous production of corrugated tube made of plastic material is associated to an extruder 2 for the extrusion of plastic material (Figures 1 and 2) .

[0032] The machine 1 comprises a first annular path 4 and a second annular path 6, side by side. Between said paths 4,6, in middle position, a coupling plane Pa is defined.

[0033] Along the paths are movable mould groups S that, according to an embodiment, are constituted by a mould- holder carriage S' and a mould S' ' , applied to the respective carriage S' and provided with an open cavity that defines one half of the imprint of the section of corrugated tube to be realised. [0034] According to a further embodiment, the mould group is constituted by a single body that present the cavity in itself.

[0035] Along each path 4,6, a rectilinear coupling section 8 is recognised, contained on the coupling plane Pa, along which the moulds S'' of the two paths are respectively coupled and form a complete imprint I, corresponding to a section of the corrugated tube. Following the direction of advancement of the moulds, there is also recognised, in succession, a curvilinear tail section 10, a return section 12, generally rectilinear, and a curvilinear head section 14.

[0036] The machine 1 also comprises a kinematic head device 20, disposed in correspondence of the head section 14, and a kinematic tail device 22, arranged in correspondence of the tail section 10, suitable to engage the mould groups S and move them along the respective paths 4,6.

[0037] The kinematic head device 20 comprises at least one toothed input wheel 30 having positioning and dimensions such as to engage the mould groups S in output from the return section 12, that are preparing to follow the head section 14 (Figure 3) .

[0038] Furthermore, preferably, the kinematic head device 20 comprises at least one toothed output wheel 32 having positioning and dimensions such as to engage the mould groups S that are preparing to follow the coupling section 8, meshing with these in the moment in which they disengage from the input wheel 30.

[0039] According to a preferred embodiment, the input wheel 30 is motorised, i.e., directly connected to a gear motor, while the output wheel 32 is kinematically engaged with the input wheel 30 to be actuated in rotation.

[0040] For example, the kinematic head device 20 comprises a toothed transmission wheel 34 that meshes with the input wheel 30 and with the output wheel 32 to transmit the rotary motion from the input wheel 30 to the output wheel 32.

[0041] In normal operation of the machine 1, several mould groups Si are preparing to enter the head section 14 (Figure 3) .

[0042] These mould groups Si are moved pushed by the mould groups that follow them; for example, a first mould group Sil is pushed by a second mould group Si2, which in turn is pushed by a third mould group Si3.

[0043] The first mould group Si is pushed to mesh with the input wheel 30 of the kinematic head device 20; said input wheel 30 meshes with the entering mould group Sil and drags it in order to move it along the head section 14, so as to separate from the mould group Si2 that follows it, until sending it to the exit of the head section 14, toward the coupling section 8 of the path 4 (Figure 4) .

[0044] At the exit of the heat section 14, several mould groups Su are preparing to follow the coupling section 8 (Figure 5) .

[0045] A first mould group Sul output is about to disengage from the input wheel 30 and, at the same time, meshes with the output wheel 32, so as to be pushed toward the coupling section 8.

[0046] In the moment in which the first exiting mould group Sul is about to disengage from the input wheel 30 and mesh with the output wheel 32, said first mould group Sul is still separated from the coupling plane Pa; in other words, a face Ac of mould group Sul, on which opens the cavity C, is spaced from the coupling plane Pa by a gap G.

[0047] Subsequently, the first exiting mould group Sul is dragged by the output wheel 32 and guided so as to perform a lateral movement such as to cancel the gap G with respect to the coupling plane Pa and bring said face Ac on said coupling plane Pa.

[0048] The mould groups Su are pushed along the coupling section; for example, a second exiting mould group SU2 pushes a third exiting mould group SU3. The whole pushing action is developed by the output wheel 32.

[0049] According to a preferred embodiment (Figures 6 and 7), the mould-holder carriage S' is constituted by a carriage body 100, typically in a single piece of steel, provided with a longitudinally pass-through compartment 102.

[0050] The carriage body 100 also comprises a support wall 104, which transversely delimits the compartment 102 on one side and intended to be engaged with the mould S' ' ; the carriage body 100 also comprises a lower wall 106 and an upper wall 108, projecting from the support wall 104, which delimit said compartment 102 interiorly and superiorly .

[0051] The walls 106, 108, on the side opposite that of the support wall 104, have teeth 110,112 for meshing with the kinematic devices 20,22 of the machine 1.

[0052] Preferably, moreover, the carriage body 100 comprises guide means suitable to engage the mould group S with counter-guide means of the machine 1 for guiding the mould group S along the paths 4,6.

[0053] For example, said guide means comprise an upper pin 114, projecting from the upper wall 108 in the compartment 102, and a lower pin 116, projecting from the lower wall 106 in the compartment 102.

[0054] Preferably, said pins 114,116 are idle, to facilitate the sliding in said guides.

[0055] Preferably, moreover, said pins are offset longitudinally; in other words, along the longitudinal direction, the axis of the first pin is offset relative to the axis of the second pin, to improve the stability of the mould group in motion.

[0056] According to a further embodiment (not shown) , the mould group S, made in a single piece, is provided with guide means comprising guide walls suitable to engage with the counter-guide means of the machine.

[0057] The machine 1 is equipped, as said, with counter- guide means suitable to engage the guide means of the mould group S .

[0058] Said counter-guide means comprise a main plate 200 that extends between the head zone and the tail zone of the machine (Figure 8) .

[0059] The plate 200, having a lower face, an upper face and a predefined thickness, has a first continuous groove 202 (in continuous line in Figure 8), for example formed on the upper face, which realises the guide for the first pin 114 of the mould group S, and a second continuous groove 204 (in dashed line in Figures 8, 9 and 10) , for example realised on the lower face, which realises the guide for the second pin 116 of the mould group S.

[0060] Said grooves 202, 204 are therefore superimposed vertically .

[0061] At the exit of the curvilinear head section 14, between the position in which the first exiting mould group Sul disengages from the input wheel 30 and engages the output wheel 32, one of said grooves 202, 204, for example the first groove 202 has a trend characterised by two sections: a first re-entrant section 202a having trend towards the inside of the path 4,6, and a successive second section 202b having outgoing trend towards the outside of the path 4,6.

[0062] The succession of the re-entrant section 202a and 202b of the outgoing section operates as a cam device, so that the first exiting mould group Sul is guided so as to perform the lateral movement that cancels the gap G with respect to the coupling plane Pa and brings face Ac on the coupling plane Pa.

[0063] According to a preferred embodiment, the kinematic head device 20 comprises a pair of coaxial toothed output wheels, and in particular a lower output wheel 32a, placed below the plate 200, and an upper output wheel 32b, placed above the plate 200; preferably, moreover, the kinematic head device 20 comprises a pair of coaxial toothed transmission wheels, and in particular a lower transmission wheel 34a, placed below the plate 200, and an upper transmission wheel 34b, placed above the plate 200 (Figure 11) .

[0064] According to a preferred embodiment, the kinematic tail device 22 is structurally and functionally identical to the kinematic head device 20.

[0065] Furthermore, the machine 1 comprises actuation means suitable for moving said kinematic devices 20,22.

[0066] For example, said actuating means comprise a single electric motor 300, for example positioned on a ground plane T, in an intermediate position, preferably centrally, between the respective plates 200 of the first path 4 and of the second path 6.

[0067] For each path 4,6, the actuation means further comprise a first shaft 302 connected to the motor 300, typically horizontal, i.e., having its rotation axis parallel to the ground plane T, a return device 304, and a second shaft 306, typically vertical, i.e., with rotation axis perpendicular to the ground plane T.

[0068] The return device 304 takes motion from the first horizontal shaft 302 and transmits it to the second vertical shaft 306.

[0069] The second shaft 306 is operatively connected to the input wheel 30, moving it in rotation.

[0070] Advantageously, the presence of a single electric motor that moves the head kinematic devices 20 of the two paths, ensures an excellent synchrony of movement of the mould groups S, essential for an optimal coupling on the coupling plane Pa.

[0071] The actuation means further comprise transfer means suitable to transfer the motion from the kinematic head device 20 to the kinematic tail device 22 (or, in a variant embodiment, vice versa) .

[0072] Said transfer means comprise for example a chain 320 engaged with the head device 20, which operates as a power take-off, and with the tail device 22, for the actuation of the latter (Figure 12) .

[0073] According to a further embodiment (Figures 13 to 15), the kinematic head device 20 comprises the input wheel 30, the output wheel 32, the transmission wheel 34, to make the output wheel 32 kinematically engaged with the input wheel 30, and an auxiliary toothed wheel 36 having positioning and dimensions such as to engage the mould groups S exiting from the return section 12, in advance of engagement with the input wheel 30, to synchronise the translation of said mould groups S with the rotation of input wheel 30 and optimise the mutual meshing between these.

[0074] The auxiliary wheel 36 is operatively engaged with the other wheels of the kinematic head device 20, and preferably directly engaged with the transmission wheel 34. [0075] In normal operation of the machine 1, several mould groups Si are preparing to enter the head section 14; the first mould group Sil is pushed to come into mesh with the auxiliary wheel 36, which synchronises the translation of said mould group Sil with the rotation of input wheel 30, so as to optimise the mesh between the mould group Sil and said input wheel 30, which drags it so as to move it along the head portion 14 up to sending it to the exit of this, towards the coupling section 8 of the path 4.

[0076] Preferably, moreover, the input wheel 30 consists of a single lower input wheel 30a, placed below the plate 200 (Figure 14), while the transmission wheel 34 is constituted by a lower transmission wheel 34a, placed below the plate 200 and an upper transmission wheel 34b, placed above the plate 200, joined by a connection hub 34c that crosses the plate 200, for example supported by bearings (Figure 15) .

[0077] Preferably, moreover, the input wheel 32 is constituted by a lower output wheel 32a, placed below the plate 200, and an upper output wheel 32b, placed above the place 200, joined by a connection hub 32c that crosses the plate 200, for example supported by bearings (Figure 15) .

[0078] Finally, preferably, the auxiliary wheel 36 is constituted by a single upper auxiliary wheel 36b, placed above the plate 200 (Figure 15) ; since the upper auxiliary wheel 36b preferably engages with the upper transmission wheel 34b, this configuration allows overcoming problems of overall dimensions and consequent dimensional interference between the input wheel 30 and auxiliary wheel 36.

[0079] In other words, the auxiliary wheel 36 is vertically superimposed to the input wheel 30 to best perform the synchronisation function of the translation of the mould group with the rotation of the input wheel.

[0080] Advantageously, said transfer means allow synchronising the movement of the head devices with the movement of the tail devices.

[0081] Advantageously, moreover, the chain also carries integrated part of the cooling circuit of the moulds.

[0082] Innovatively, the machine according to this invention overcomes the prior art drawbacks, since it is suitable to work even at his translation speeds of the mould groups .

[0083] For example, the Applicant considers it possible to reach speeds of 30 metres/minute on machines for the production of medium-small corrugated tube.

[0084] In particular, the kinematic device of which the machine is equipped allows separating the mould groups that are preparing to follow a curvilinear section of the path .

[0085] It is clear that one skilled in the art, in order to meet contingent needs, may make changes to the machine described above, all contained within the scope of protection defined by the following claims.

Claims

1. Machine (1) for the continuous production of a corrugated tube comprising:

- a plurality of mould-groups (S) each provided with a face (Ac) and a cavity (C) open on said face (Ac) ;

- a first annular path (4) and a second annular path (6) , side by side, for the movement of said mould-groups (S) , in which said paths (4,6) each comprise:

i) a coupling section (8) along which the face (Ac) of the mould groups of the first path (4) is facing the face

(Ac) of the mould groups of the second path (6) , so that the respective cavities (C) define a complete imprint (I) of a section of the corrugated tube;

ii) a curved head section (14), upstream of the coupling section ( 8 ) ;

- at least one kinematic head device (20) comprising: i) at least one toothed input wheel (30) to engage a first mould group (S) and move it along said head section (14) separating it from a successive mould group (S) that follows it along the path (4,6);

ii) at least one toothed output wheel (32), kinemat ically engaged with the input wheel (30) to be actuated in rotation, wherein the input wheel (30) yields said first mould group (S) , to engage with it and move it towards the coupling path (8) .

2. Machine according to claim 1, wherein the kinematic head device (20) comprises at least one toothed transmission wheel (34) that meshes with the input wheel (30) and with the output wheel (32) to transmit the rotary motion from the input wheel (30) to the output wheel (32) .

3. Machine according to claim 1 or 2, wherein the kinematic head device (20) comprises a toothed auxiliary wheel (36), kinematically engaged with at least one of the other wheels of the kinematic head device (20), having positioning and dimensions such as to engage the mould groups (S) in advance with respect to the engagement with the input wheel (30) for synchronising the translation of said mould groups (S) with the rotation of the input wheel (30) .

4. Machine according to claim 2 and 3, wherein the auxiliary wheel (36) meshes directly with the transmission wheel (34) .

5. Machine according to claim 3 or 4, wherein the auxiliary wheel (36) is superimposed vertically to the input wheel (30) to prevent interference due to the respective overall dimensions.

6. Machine according to any of the preceding claims, comprising a main plate (200) that extends between a head zone and a tail zone of the machine, wherein said plate (200) has a lower face, an upper face and a predefined thickness .

7. Machine according to claim 6, wherein the input wheel (30) is constituted by a single lower input wheel (30a), positioned below the plate (200) .

8. Machine according to claim 6 or 7, when dependent on claim 2, wherein the transmission wheel (34) is constituted by a lower transmission wheel (34a), placed below the plate (200), and an upper transmission wheel (34b) , placed above the plate (200) .

9. Machine according to any of claims 6 to 8, wherein the output wheel (32) is constituted by a lower output wheel (32a), placed below the plate (200), and an upper output wheel (32b), placed above the plate (200) .

10. Machine according to any of claims 6 to 9, when dependent on claim 3, wherein the auxiliary wheel (36) is constituted by a single upper auxiliary wheel (36b), placed above the plate (200) .