Operating unit for the laser welding of components in an article manufacturing machine

Abstract

An operating unit (1) for an article manufacturing machine is described, the unit being designed to perform laser welding on two components of the articles with a number of laser welding devices (2) located in the area of a laser welding station (S) for the laser welding of the two components; a support (3) rotating around a first axis (X) provided with a pair of arms (4) connected at respective opposite ends of said support (3); wherein each arm (4) comprises a number of elements (5), each of which is configured to cooperate with a respective laser welding device (2) and is provided with a nozzle (6) defined by a hollow body and configured to come into contact with the components to be welded and to hold the two components to be welded in contact with one another during the entire welding process; and a number of cleaning devices (7) for cleaning said laser nozzles (6) located in the area of a cleaning station (G); wherein the support (3) is designed to place a first arm (4*, 4**) in the area of the laser welding station (S) and a second arm (4*, 4**) in the area of the cleaning station (G).

Description

[0001] "Operating unit for the laser welding of components in an article manufacturing machine"

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This Patent Application claims priority from Italian Patent Application No. 102024000008989 filed on April 19, 2024, the entire disclosure of which is incorporated herein by reference.

[0004] TECHNICAL FIELD

[0005] This invention relates to an operating unit for the laser welding of components in an article manufacturing machine.

[0006] PRIOR ART

[0007] As is well known, a manufacturing machine for the production and / or assembly of articles, e.g. in the context of electronic cigarettes, generally comprises a feed system that extends along a processing path and comprises multiple processing stations that are arranged in succession along the feed system and are implemented to feed components of the article or to perform processing on the semi-finished articles.

[0008] In some cases, there is a processing unit configured to carry out laser welding of components preferably made of plastic or thermoplastic material, or even metal.

[0009] In this regard, there is more and more need for technical solutions to improve the operation of said laser welding units. In particular, known laser welding units typically comprise a conveyor for transporting the components to be welded, provided with multiple support devices, each of which is configured to accommodate a number of pairs of components to be welded together. The components to be welded travel along a welding path from an input station for the components to be welded to an output station for the welded components.

[0010] Known laser welding units also include an actual laser welding station arranged along the welding path between the input station for the components to be welded and the output station for the welded components. At the laser welding station, there are a number of laser welding devices, each comprising a laser head that houses optical means inside that cooperate with a laser beam, carried by an optical fibre mechanically connected to the laser head. Each laser welding device comprises a nozzle defined by a hollow body with a truncated cone shape, i.e. tapered downwards towards the components to be welded. In use, the nozzle is in fact placed near and facing the components to be welded. Each nozzle is configured to co-operate with a respective laser head; more specifically, each nozzle is configured to let the laser beam pass through an output opening and, in addition, to press the respective pair of components to be welded, i.e. to be positioned in contact with the components to be welded and to keep the two components to be welded in contact with each other during the entire welding process.

[0011] In use, the nozzle is hit by fumes and dust generated during the welding process and deposited on the inner surface. After a certain number of operating cycles, a thorough cleaning of the nozzles is necessary, normally carried out using abrasive devices (such as brushes). The nozzles are cleaned by rubbing against abrasive devices and restored to their original condition.

[0012] WO2018078565, JP2883486, and US2019099834 describe known laser welding stations. DESCRIPTION OF THE INVENTION

[0013] The purpose of this invention is to provide an operating unit for the laser welding of components in an article manufacturing machine that is free from the drawbacks of the state of the art and is easy and inexpensive to manufacture.

[0014] According to this invention, an operating unit for laser welding of components in an article manufacturing machine is provided according to the attached claim.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] This invention will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment thereof, wherein:

[0017] Figure 1 is a perspective view of an operating unit for the laser welding of components in an article manufacturing machine made in accordance with this invention and with parts removed for clarity; and

[0018] Figure 2 is an additional perspective view of the laser welding operating unit in Figure 1.

[0019] PREFERRED EMBODIMENTS OF THE INVENTION

[0020] A manufacturing machine for the production of articles comprises a feed system that extends along a processing path and multiple operating (or processing) units that are arranged in succession along the feed system and are implemented to feed various components of the semi-finished article or to perform processing on the semi-finished articles. Advantageously but not exclusively, the articles are used in the electronic cigarette sector.

[0021] The manufacturing machine also includes, among other things, a unit 1 for welding the two components of the article. More specifically, the welding unit 1 performs laser welding.

[0022] Advantageously, the two components of the article to be welded together are made of plastic or thermoplastic material, or even metal. The laser welding unit 1 is configured to weld components of various thicknesses.

[0023] The laser welding unit 1 comprises a transport conveyor for the components to be welded (known and not illustrated); the transport conveyor comprises, for example, a drum rotating around an axis or a linear conveyor (belt or chain).

[0024] The conveyor supports multiple support devices, each of which is configured to define a seat to accommodate a number of pairs of components to be welded together. Advantageously, each support device is equipped with jaws that hold a respective pair of components to be welded during the welding process.

[0025] The components to be welded travel along a welding path from an input station for the components to be welded to an output station for the welded components. The laser welding station 1 comprises a feed device (not illustrated) for the components to be welded within the support devices arranged at the input station and a collecting device (not illustrated) for the welded components to take them from the support devices and transfer them downstream of the laser welding station 1.

[0026] The laser welding unit 1 also includes an actual laser welding station S arranged along the welding path between the input station for the components to be welded and the output station for the welded components.

[0027] A number of laser welding devices 2 are provided at the laser welding station S. Advantageously, two laser welding devices 2 are provided at the laser welding station S, essentially arranged side-by-side to improve the productivity of the laser welding unit 1. The two laser welding devices 2 are essentially identical.

[0028] Each laser welding device 2 comprises a laser head that houses optical means inside that cooperate with a laser beam; the laser beam is transported by an optical fibre mechanically connected to the laser head.

[0029] The laser welding unit 1 also includes a support 3 that rotates around an essentially vertical axis X. The support 3 is rotated around the axis X by means of known drive means. The support 3 is provided with a number of arms 4. In particular, the support 3 is provided with a pair of arms 4, which are essentially identical to each other and are connected at opposite ends of the rotating support 3. Each arm 4 comprises a first portion connecting with the rotating support 3 and a second portion extending radially outwards from the rotating support 3 and having an essentially circular shape in plan. Each arm comprises (supports) a number of elements 5 that are essentially identical. In particular, each second portion comprises (supports) a number of elements 5 that are substantially identical and essentially arranged side by side. In particular, each arm 4 comprises a number of elements 5 equal to the number of laser welding devices 2. Each arm 4 preferably comprises two elements 5. Each of said elements 5 is associated with a respective laser welding device 2. Each of said elements 5 is configured to cooperate, in use, with a respective laser welding device 2.

[0030] Each element 5 comprises a nozzle 6 defined by a hollow body with an axis Y. In use, the nozzle 6 is configured to be positioned at the laser welding station S in a position facing a respective support device and, consequently, a respective pair of components to be welded. The nozzle 6 preferably comprises a truncated cone-shaped wall. In other words, the nozzle 6 is tapered downwards, i.e. towards the components to be welded. Alternatively, the nozzle 6 preferably comprises a cylindrical wall. Advantageously, each nozzle 6 is configured to co-operate with a respective laser head. More specifically, each nozzle 6 is configured to let the laser beam produced by the respective laser head pass through an output opening.

[0031] In addition, each nozzle 6 is configured to press the respective pair of components to be welded. In other words, each nozzle 6 is configured to be in contact with the components to be welded and keep them in contact with each other throughout the entire welding process

[0032] In use, at the laser welding station S, the arm 4 is interposed between the respective (two) support devices of the components to be welded and the respective (two) laser heads. In use, the end of the nozzle 6 is hit by the fumes generated during the welding process, which are deposited on the inner surface of the nozzle 6.

[0033] The laser welding unit 1 therefore includes a cleaning station G for cleaning the nozzles 6. The cleaning station G for cleaning nozzles 6 is diametrically opposite the laser welding station S with respect to the axis X.

[0034] In other words, while a first arm 4* is located at the laser welding station S, a second arm 4** is located at the cleaning station G, and vice versa. That is, while the second arm 4** is located at the laser welding station S, the first arm 4* is located at the cleaning station G, and vice versa.

[0035] Each of the two arms 4 is configured to rotate 180° around the axis X to move from a position at the laser welding station S to a position at the cleaning station G; and vice versa, to move from the position at the cleaning station G to the position at the laser welding station S. More specifically, each arm 4 is rotated by the support 3 around the axis X.

[0036] The laser welding unit 1 includes cleaning devices 7 for cleaning nozzles 6 arranged at said cleaning station G for cleaning nozzles 6.

[0037] According to a first embodiment, the cleaning devices 7 for cleaning nozzles comprise a number of dispensing devices 8. More specifically, the cleaning devices 7 for cleaning nozzles 6 comprise a number of dispensing devices 8 equal to the number of elements 5 (and, therefore, of the nozzles 6 to be cleaned). The cleaning devices 7 for cleaning nozzles preferably comprise two dispensing devices 8 arranged essentially side-by-side. According to a first embodiment, the dispensing devices 8 are fixed. When each of the two arms 4 is in the position at the cleaning station G, the dispensing devices 8 are configured to be positioned close to and facing the respective nozzles 6 to be cleaned.

[0038] According to an additional embodiment, the dispensing devices 8 are not fixed. More specifically, the dispensing devices 8 are movable in an essentially vertical direction between a first operating position in which they are close to and facing the respective nozzles 6 to be cleaned and a second inactive position in which they are at a distance from the respective nozzles 6 to be cleaned.

[0039] Advantageously, the dispensing devices 8 are connected to an air supply circuit and are configured to feed a flow of pressurised air to the respective nozzle 6 in order to remove dust and fume deposits on the inner surface.

[0040] According to a preferred embodiment, the laser welding unit 1 comprises a recovery system (not illustrated) designed to remove, preferably by suction, the dust removed during cleaning of the nozzles 6 by the dispensing devices 8. The recovery system comprises a suction inlet located close to (below) the dispensing devices 8 that feeds the dust removed during cleaning of the nozzles 6 to a collecting tank. According to a second embodiment, the cleaning devices 7 for cleaning nozzles comprise a number of abrasive cleaning devices 9. The abrasive cleaning devices 9 preferably include brushes. The nozzles 6 are cleaned by rubbing against the abrasive cleaning devices 9.

[0041] According to a preferred embodiment, the laser welding unit 1 comprises a recovery system (not illustrated) designed to remove, preferably by suction, the dust removed during cleaning of the nozzles 6 using the abrasive devices 9. The recovery system comprises a suction inlet located close to (below) the abrasive devices 9 that feeds the dust removed during cleaning of the nozzles 6 to a collecting tank.

[0042] According to another embodiment, the cleaning devices 7 for cleaning nozzles 6 comprise both a number of abrasive cleaning devices 9 and a number of dispensing devices 8.

[0043] In particular, the cleaning station G for cleaning the nozzles 6 comprises a support structure 10 shared by the abrasive cleaning devices 9 and by the dispensing devices 8. The abrasive cleaning devices 9 preferably include brushes. The cleaning devices 7 for cleaning nozzles 6 preferably comprise a number of dispensing devices 8 equal to the number of elements 5 (and, therefore, of the nozzles 6 to be cleaned). The cleaning devices 7 for cleaning the nozzles 6 preferably comprise two dispensing devices 8 arranged essentially side-by-side. According to a first embodiment, the dispensing devices 8 are fixed. When each of the two arms 4 is in the position at the cleaning station G, the dispensing devices 8 are configured to be positioned close to and facing the respective nozzles 6 to be cleaned. According to an additional embodiment, the dispensing devices 8 are not fixed. More specifically, the dispensing devices 8 are movable in an essentially longitudinal direction between a first operating position in which they are close to and facing the respective nozzles 6 to be cleaned and a second inactive position in which they are at a distance from the respective nozzles 6 to be cleaned. Advantageously, the dispensing devices 8 are connected to an air supply circuit and are configured to feed a flow of pressurised air to the respective nozzle in order to remove dust and fume deposits on the inner surface.

[0044] In this case, according to a preferred embodiment, the abrasive cleaning devices 9 are arranged upstream of the dispensing devices 8 along the path of each arm 4 from the laser welding station S to the cleaning station G. In other words, the nozzles 6 are first cleaned by rubbing on the abrasive cleaning devices 9 and then using the dispensing devices 8.

[0045] Alternatively, the abrasive cleaning devices 9 are arranged downstream of the dispensing devices 8 along the path of each arm 4 from the laser welding station S to the cleaning station G. In other words, the nozzles 6 are first cleaned using the dispensing devices 8 and then by rubbing on the abrasive cleaning devices 9.

[0046] Advantageously, the support structure 10 is arranged in such a position that it does not hinder (or block) the movement of the support 3 and, more specifically, the arms 4. In other words, the support structure 10 is arranged at such a distance from the support 3 and the arms 4 that it does not prevent rotation around the axis X.

[0047] According to a preferred embodiment, a screening device 11 is provided at the welding station S, defined by a pair of screening elements 12 arranged side-by-side. Each screening element 12 is movable along an axis Z between a raised position in which it is at a distance from a respective support device and, consequently, from a respective pair of components to be welded, and a lowered operating position in which it encloses the components to be welded and the respective laser welding devices 2 to define a closed welding chamber; and vice versa. In particular, in the lowered position, each screening element 12 cooperates with its respective support device to delimit the closed welding chamber. The screening element 12 is movable along the axis Z preferably transverse to the axis X. Each screening element 12 is moved using known drive means (such as, for example, an electric motor or a pneumatically driven piston). Each screening element 12 is moved separately and independently of the rotating support 3. Each screening element 12 preferably reaches the lowered position when the nozzle 6 is already in contact with the components to be welded.

[0048] The method for laser welding the components using the laser welding station 1 described in the preceding discussion is described below.

[0049] In particular, the following steps occur in succession: each pair of components is transferred into the respective support device at the input station; the support device travels along the welding path from the input station to the laser welding station S; the arm 4* is located at the laser welding station S, in particular, each element 5 (with its respective nozzle 6) is interposed between the support device and the respective laser head; at the same time, the arm 4** is located at the cleaning station G; the nozzles 6 are placed in contact with the pair of welding elements and then the screening elements 12 are moved from the raised position to the lowered operating position; laser welding of the components housed in the support device is carried out by means of the laser welding devices 2; the nozzle 6 is kept in contact with the components to be welded for the duration of the laser welding of the components; once the laser welding phase of the components is complete, the screening elements 12 are moved from the lowered operating position to the raised position and the drive means rotate the rotating support 3 around the axis X; in particular, the support 3 rotates 180° around the axis X so that the arm 4* moves from the laser welding station S to the cleaning station G and the arm 4** moves from the cleaning station G to the laser welding station S; at the cleaning station G, the nozzles 6 of the arm 4* are cleaned using the cleaning devices 7; in particular, the nozzles 6 of the arm 4* are firstly cleaned by rubbing on the abrasive cleaning devices 9 and, subsequently, by the flow of air fed by the dispensing devices 8; and at the same time, once the welding of the components is complete, the support device travels along the welding path until it reaches the output station where the pair of soldered components is picked up by the support device and transferred downstream to the welding station 1.

[0050] LIST OF REFERENCE NUMBERS

[0051] 1 laser welding unit

[0052] 2 laser welding devices

[0053] 3 support

[0054] 4, 4*, 4** arms

[0055] 5 elements

[0056] 6 nozzle

[0057] 7 cleaning devices

[0058] 8 dispensing devices

[0059] 9 abrasive devices

[0060] 10 support structure

[0061] 11 screening device

[0062] 12 screening element

[0063] S laser welding station

[0064] X axis

[0065] Y axis

[0066] Z axis

[0067] G cleaning station

Claims

C L A I M S1. An operating unit (1) for an article manufacturing machine designed to perform laser welding on two components of the articles comprising: a number of laser welding devices (2) located in the area of a laser welding station (S) for the laser welding of the two components and a support (3) capable of rotating around a first axis (X); the unit is characterised in that the support (3) is provided with a pair of arms (4) connected in the area of respective opposite ends of said support (3); wherein each arm (4) comprises a number of elements (5), each of which is configured to cooperate with a respective laser welding device (2) and is provided with a nozzle (6) defined by a hollow body and configured to come into contact with the components to be welded and to hold the two components to be welded in contact with one another during the entire welding process; and a number of cleaning devices (7) for cleaning said nozzles (6) located in the area of a cleaning station (G); wherein the support (3) is designed so that while a first arm (4*, 4**) is in the area of the laser welding station (S), a second arm (4*, 4**) is in the area of the cleaning station (G), and vice versa.

2. The unit according to claim 1, wherein the laser welding station (S) is diametrically opposite the cleaning station (G) relative to the first axis (X).

3. The unit according to claim 1 or 2, wherein each arm (4) is configured to make a 180° rotation around the first axis (X) so as to move from the laser welding station (S) to the cleaning station (G) and vice versa.

4. The unit according to any one of the preceding claims, wherein said nozzle (6) is configured to place itself in the area of the laser welding station (S) in a position facing the components to be welded; wherein the nozzle (6) has a tapered shape towards the components to be welded and is configured to allow the laser beam produced by the respective laser welding device (2) to go through an output opening.

5. The unit according to any one of the preceding claims, wherein the cleaning devices (7) comprise a number of abrasive cleaning devices (9), in particular brushes; wherein said nozzle (6) is cleaned because of the friction on the abrasive cleaning devices (9).

6. The unit according to any one of the preceding claims, wherein the cleaning devices (7) comprise a number of dispensing devices (8), each associated with a respective element (5); wherein the dispensing devices (8) are connected to an air supply circuit and are configured to supply a flow of air under pressure to the respective nozzle(6).

7. The unit according to claim 5 and 6, wherein the cleaning station (G) comprises a support structure (10) shared by the abrasive cleaning devices (9) and by the dispensing devices (8).

8. The unit according to claim 5 and 6, wherein the abrasive cleaning devices (9) are located upstream of the dispensing devices (8) along the path from the laser welding station (S) to the cleaning station (G) so that said nozzle (6) is cleaned, at first, through friction on the abrasive cleaning devices (9) and, subsequently, by means of the dispensing devices (8).

9. The unit according to any one of the preceding claims and comprising a recovery system designed to remove, preferably through suction, the powders removed during the cleaning of the nozzles (6) by means of the cleaning devices (7); wherein said recovery system comprises a suction mouth, which is located close to the cleaning devices(7) and feeds the powders removed during the cleaning of the nozzles (6) to a collecting tank.

10. The unit according to any one of the preceding claims and comprising a screening device (11) located in the area of the laser welding station (S) and providedwith a number of screening elements (12), each associated with a respective laser welding device (2).

11. The unit according to claim 10, wherein each pair of components to be welded is housed in a respective support device and each screening element ( 12) is movable along a second axis (Z), preferably transverse to the first axis (X), between a lifted position, in which it is at a distance from the respective support device, and a lowered operating position, in which it cooperates with the respective support device to delimit a closed welding chamber.

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