Apparatus for processing tubes and profiles, with a system for detecting the position of the trailing end of the tube or profile to be processed

Abstract

The present application relates to an apparatus for processing tubes and profiles (T) comprising: a working head, holding means (16, 18) configured to hold the tube or profile (T) to be processed at a trailing end (TE) thereof, opposite to a leading end (LE) of the tube or profile (T) facing the working head, said holding means (16, 18) defining a feed axis (x) of the apparatus and comprising a tube-holding carriage (16) adapted to translate along the feed axis (x) between a maximum advance position, i.e., a position of minimum distance from the working head (12), and a maximum withdraw position, i.e., a position of maximum distance from the working head (12); loading means configured to support each time a tube or profile (T) to be processed in a loading position, in which the tube or profile (T) is arranged with its longitudinal axis parallel to, but at a distance from, the feed axis (x), and to transfer the tube or profile (T) from the loading position to a working position, in which the tube or profile (T) is arranged with its longitudinal axis aligned with the feed axis (x) to be held by the holding means (16, 18); first sensor means (24) mounted on the tube-holding carriage (16) and configured to detect, as the tube-holding carriage (16) is being moved backward along the feed axis (x) from the maximum advance position to the maximum withdraw position, with the tube or profile (T) placed in the loading position, a condition of reaching of the trailing end (TE) of the tube or profile (T); and a control unit configured to control the translational movement of the tube-holding carriage (16) along the feed axis (x), said control unit being connected to the first sensor means (24) so as to be able to determine the axial position of the trailing end (TE) of the tube (T) based on the signals provided by the first sensor means (24).

Description

[0001] APPARATUS FOR PROCESSING TUBES AND PROFILES, WITH A SYSTEM FOR DETECTING THE POSITION OF THE TRAILING END OF THE TUBE OR PROFILE TO BE PROCESSED

[0002] Technical field of the invention

[0003] The present invention relates to an apparatus for processing tubes and profiles, for example an apparatus for cutting or welding tubes and profiles (particularly, though not necessarily, by means of a laser beam), of the type specified in the preamble of independent claim 1.

[0004] More specifically, the present invention relates to a tube and profile processing apparatus provided with a detection system configured to detect the position of the trailing end of the tube or profile to be processed, i.e. , the position of the end of the tube to be processed opposite to the one facing the working head of the apparatus.

[0005] State of the art

[0006] A tube and profile processing apparatus of the type specified in the preamble of independent claim 1 is known, for example, from CN 204 035 798 U.

[0007] Typically, in tube and profile processing apparatuses, particularly in tube and profile laser cutting or welding apparatuses, the tube or profile to be processed is initially placed in a loading position on board of the apparatus, in which the tube or profile is arranged with its longitudinal axis parallel to, but at a distance from, a feed axis (or working axis) of the apparatus, and then transferred from that loading position to a working position, in which the tube or profile is arranged with its longitudinal axis aligned with the feed axis of the apparatus. With the tube or profile positioned in the working position, a tube-holding carriage of the apparatus, which is provided with holding means configured to hold each time the tube or profile to be processed at its trailing end and is mounted so as to be able to translate along the feed axis of the apparatus, can hold with its holding means the trailing end of the tube and gradually advance it along the feed axis towards the working head of the apparatus. The tube-holding carriage is adapted to translate along the feed axis between a maximum withdraw position, in which it is at the maximum distance from the working head to hold the tube or profile to be processed at its trailing end, and a maximum advance position, in which it is at the minimum distance from the working head to bring the end section of the tube or profile that is being processed, i.e., the section of the tube or profile close to the trailing end, into the working area where that section can be processed by the working head. At each work cycle of the apparatus, therefore, the tube-holding carriage, starting from the maximum withdraw position, is advanced along the feed axis towards the working head until it reaches the maximum advance position, and when the processing of the tube or profile is completed, it is moved backward until it returns to the maximum withdraw position to hold a new tube or profile to be processed. In order to allow the tube-holding carriage to hold the trailing end of the tube or profile to be processed, the apparatus is generally provided with a detection system including, for example, a photocell arranged in a front area of the tube-holding carriage, i.e., in an area of the tube-holding carriage facing the working head, in particular in a position slightly forward (for example by a few centimetres) of the holding means of the tube-holding carriage. In this case, the maximum withdraw position of the tube-holding carriage is established to ensure that in such a position the holding means of the tube-holding carriage are at a certain safe distance from the trailing end of the tube or profile to be processed when the latter is moved from the loading position to the working position. Such a maximum withdraw position may even be at a distance of the order of 1-2 metres from the trailing end of the tube or profile. At this point, with the tube or profile in the working position, the tube-holding carriage is moved forward slowly and the photocell mounted on the tube-holding carriage is used to intercept the trailing end of the tube or profile. As soon as the trailing end of the tube or profile is intercepted by the photocell, the tube-holding carriage will be advanced by a distance (which is precisely known, since it is determined by the position of the photocell in relation to the holding means of the tube-holding carriage) sufficient to bring the holding means into a position where the tube or profile can be gripped at its trailing end. A tube and profile processing apparatus provided with such a detection system is disclosed, for example, in CN 211 804 434 II.

[0008] However, such a way of controlling the relative position of the tube-holding carriage with respect to the trailing end of the tube or profile to be processed has the disadvantage that it takes some time and thus results in a longer cycle time.

[0009] Summary of the invention

[0010] It is an object of the present invention to provide an apparatus for processing tubes and profiles that makes it possible to reduce the time required by the tube-holding carriage to hold the tube or profile to be processed starting from when the tube or profile is placed in the working position. This and other objects are fully achieved according to the present invention by a tube and profile processing apparatus as defined in the appended independent claim 1.

[0011] Advantageous embodiments of the invention are specified in the dependent claims, the subject-matter of which is to be intended as forming an integral part of the following description.

[0012] In summary, the invention is based on the idea of providing the apparatus with a detection system comprising sensor means arranged on one side of the tube-holding carriage facing the loading position of the tube or profile and configured to determine, as the tube-holding carriage is being moved backward along the feed axis of the apparatus in its movement from the maximum advance position to the maximum withdraw position, with the tube or profile to be processed placed in the loading position, the position of the trailing end of the tube or profile.

[0013] Thanks to such a detection system, the axial position of the trailing end of the tube or profile to be processed is determined during the return movement of the tube-holding carriage from the maximum advance position to the maximum withdraw position, without thereby requiring a specific time for carrying out this operation. Since the axial position of the trailing end of the tube or profile to be processed is known, it is possible to position the tube-holding carriage in an initial working position closer to that end and thus reduce the travel the tube-holding carriage must make to move from the maximum withdraw position to the tube or profile holding position. In addition, since, when the tube-holding carriage is in the maximum withdraw position, the axial position of the trailing end of the tube or profile to be processed is already precisely known, it is possible to speed up the movement of the tube-holding carriage from the maximum withdraw position to the tube or profile holding position.

[0014] Furthermore, such a detection system makes it possible to accurately measure the length of the tube or profile to be processed by using the photocell (or other device) normally present at a given point near the working area of the apparatus to detect the time when the leading end of the tube or profile to be processed reaches that point. In fact, once, by means of the detection system according to the invention, the initial axial position of the trailing end of the tube or profile to be processed is known, it is possible to know the axial position of the trailing end of the tube or profile when the leading end of the tube or profile is intercepted by the photocell near the working area. The length of the tube or profile to be processed thus results from the distance between the axial position of the photocell and the axial position of the trailing end of the tube or profile at the time when the leading end is intercepted by the photocell. Brief description of the drawings

[0015] Further features and advantages of the present invention will be apparent from the following detailed description, given purely by way of non-limiting example with reference to the attached drawings, in which:

[0016] - Figure 1 is a perspective view of a tube and profile processing apparatus according to an embodiment of the present invention;

[0017] - Figures 2 to 7 are schematic plan views showing the method of detecting the axial position of the trailing end of a tube and measuring the length of the tube in the apparatus of Figure 1 ; and

[0018] - Figure 8 shows on an enlarged scale the detail A of Figure 7.

[0019] Detailed description

[0020] In the following description and claims, the terms “longitudinal” and “axial” are used to identify a direction coincident with, or parallel to, a feed axis (or working axis) of the apparatus, while the term “transverse” is used to identify a direction lying in a plane perpendicular to the feed axis of the apparatus.

[0021] Referring first to Figure 1 , an apparatus for processing tubes and profiles according to the invention is generally indicated with 10. In the example proposed herein, the apparatus is an apparatus for cutting, particularly for laser cutting, tubes and profiles, but the invention is equally applicable to other types of tube and profile processing apparatuses.

[0022] The apparatus 10 comprises, in a per-se-known manner, a working head 12 adapted to perform machining operations on a tube or profile, for example by means of a focused laser beam. In the present case, such machining operations consist in cutting operations, but they might also include other operations, such as welding operations. The apparatus 10 is capable of processing tubes having a cross-section of any shape, e.g., circular, square, or rectangular, as well as profiles of any shape, e.g., C-profiles, T-profiles, IPE- profiles, HEA-profiles, and the like. For convenience, only the term tube will be used in the following description, it being understood, however, that what is explained below is equally applicable to the case where the apparatus is used for the processing of a profile. The working head 12 is carried by a driving system (not shown in the drawings, but in any case of a per-se-known type) adapted to move the head with one or more degrees of freedom, so as to enable the apparatus to perform on the tube the intended machining operations.

[0023] In the vicinity of the working head 12, in the present case immediately upstream of it, a support device 14 is provided, which is adapted to support the tube being processed in a section thereof close to the working area, and also to allow the tube to rotate about its longitudinal axis. The support device 14 might even be arranged immediately downstream of the working head 12. In a per-se-known manner, the support device 14 may be stationary, that is, fixed relative to a base structure of the apparatus 10, or be movable along the direction of the longitudinal axis of the tube when the latter is in the working position.

[0024] The apparatus 10 further comprises a tube-holding carriage 16 provided with holding means 18 configured to hold the tube at an end thereof (trailing end, denoted TE in Figures 2 to 7) opposite to the one (leading end, denoted LE in Figures 2 to 8) on which the working head 12 operates. Such holding means define a feed axis (or working axis) x of the apparatus, with which the longitudinal axis of the tube is aligned during processing.

[0025] With reference also to Figures 2 to 4, the tube to be processed (denoted T in those Figures) is initially placed in a loading position, in which it is arranged with its longitudinal axis parallel to, but at a distance from, the feed axis x of the apparatus 10. In that position, the tube T is supported on a plurality of loading devices 20 of the apparatus 10 (shown only in Figure 1). In order to be processed by the working head 12, the tube T is then transferred by suitable transfer devices 22 (also shown only in Figure 1) from the loading position to the working position, in which the tube is arranged with its longitudinal axis aligned with the feed axis x of the apparatus 10. At this point, the tube T is held by the holding means 18 of the tube-holding carriage 16 to be advanced during processing along the feed axis x, and, if necessary, also rotated about that axis. The support device 14 located near the working head 12 supports and guides the tube T that is being processed, keeping the longitudinal axis thereof aligned with the feed axis x.

[0026] In order to hold the tube T that is being processed and advance it along the feed axis x towards the working head 12, the tube-holding carriage 16 moves along the feed axis x between a maximum withdraw position, in which it is at the maximum distance from the working head 12, and a maximum advance position, in which it is at the minimum distance from the working head 12. Once the processing of the tube is finished, the tubeholding carriage 16 is returned to the maximum withdraw position so that another tube, which during the processing of the previous tube has been brought to the loading position, can be transferred from the loading position to the working position.

[0027] The apparatus 10 is provided with first sensor means configured to detect, as the tubeholding carriage 16 is moved back along the feed axis x from the maximum advance position to the maximum withdraw position, with the tube T to be processed placed in the loading position, the condition where said means reach the trailing end TE of the tube T, so as to allow to detect the axial position (i.e., the position along the feed axis x) of that end. Thus, in general, the first sensor means are able to discriminate between a condition of presence or a condition of absence of the tube T in the loading position, alongside the tube-holding carriage 16, while the latter is being moved backward along the feed axis x.

[0028] The first sensor means preferably comprise a contactless sensor 24. The sensor 24 may be a distance sensor (or telemeter), such as a time-of-flight distance sensor, configured to measure the distance from the tube T when the latter is in the loading position, thus alongside the tube-holding carriage 16. Instead of a distance sensor, a proximity sensor, capable of providing a signal of presence or absence of the tube, might also be used. The sensor 24 is suitably connected to a control unit of the apparatus 10, so that the control unit can manage the process of holding the tube T by means of the holding means 18 of the tube-holding carriage 16 based on the signals transmitted by this sensor.

[0029] The sensor 24 is mounted on the side of the tube-holding carriage 16 that, with the tube T to be processed positioned in the loading position, faces the tube itself. In the example proposed herein, in which the tube in the loading position is arranged on the right side of the apparatus 10 with respect to the feed axis x (according to the point of view of a person looking at the working head 12 from the tube-holding carriage 16), the sensor 24 is placed on the right side of the tube-holding carriage 16. Specifically, according to the illustrated embodiment, the sensor 24 is mounted on an arm 26, which in turn is mounted on the tube-holding carriage 16 so as to move integrally with the latter along the feed axis x. The arm 26 may be fixed or be movable between an operating position, in which it protrudes laterally from tube-holding carriage 16 to such an extent as to allow the sensor 24 to perform its tube detection function, and a non-operating position, in which it is retracted or folded away from the operating position so as to limit the overall lateral footprint of the tube-holding carriage 16.

[0030] In addition, as can be better observed in the detail view in Figure 8, the apparatus 10 is provided with second sensor means that are mounted on a component of the apparatus, in particular a component located near the working area of apparatus 10, i.e., near the area of the apparatus in which the working head 12 operates, and are configured to intercept the leading end LE of the tube T to be processed as a result of the relative movement of the tube T with respect to that component along the feed axis x.

[0031] In the embodiment proposed herein, the second sensor means are mounted on the support device 14, in particular so as to determine the time at which the leading end LE of the tube T comes out of a through opening 28 in the support device 14, but they might also be mounted on another component of the apparatus, be it a stationary component or, like the support device 14, a component having a controlled translational motion along the feed axis x.

[0032] The second sensor means comprise, for example, a photoelectric sensor (or photocell), with a transmitter 30 capable of transmitting a light beam L and a receiver 32 capable of receiving the light beam L transmitted by the transmitter 30. In this case, the transmitter 30 and the receiver 32 will be suitably arranged so that the light beam L transmitted by transmitter 30 hits the tube T when the latter crosses the plane in which the light beam L lies. In the example proposed herein, the transmitter 30 and the receiver 32 are mounted on a vertical front face 14a of the support device 14, on diametrically opposite sides with respect to the through opening 28, so that the light beam L transmitted by the transmitter 30 intersects the feed axis x.

[0033] The operation of the apparatus 10 will now be described in detail, with specific reference to the function of the first and second sensor means illustrated above.

[0034] Figure 2 shows the condition in which, with the tube T arranged in the loading position, the tube-holding carriage 16 is moved along the feed axis x from the maximum advance position towards the maximum withdraw position. At this stage, the sensor 24, which is drivingly connected with the tube-holding carriage 16 and therefore moves together with the latter parallel to the feed axis x, thus parallel to the longitudinal axis of the tube T, continuously detects the distance from the lateral surface of the tube T.

[0035] As soon as the sensor 24 reaches the trailing end TE of the tube T (Figure 3), the control unit of the apparatus 10 detects an abrupt change in the distance detected by the sensor 24 and interprets it as the condition of reaching of the trailing end TE, storing the axial position reached at that time by the sensor 24 (and thus, knowing the axial distance between the holding means 18 of the tube-holding carriage 16 and the sensor 24, also the axial position reached at that time by the holding means 18).

[0036] At this point, the tube-holding carriage 16 is moved further backward until the holding means 18 are brought to a certain distance from the trailing end TE of the tube T, as shown in Figure 4. Since the control unit of the apparatus now knows precisely the position of the trailing end TE of the tube T, it is able to control this further backward movement of the tube-holding carriage 16 so as to minimize the distance between the holding means 18 and the trailing end TE. Such distance may be on the order of centimetres or tens of centimetres, thus lower by at least one order of magnitude than the distance at which the tube-holding carriage is positioned in the current apparatuses. The tube-holding carriage 16 is now in the maximum withdraw position. With the tubeholding carriage 16 stationary in that position, the tube T is transferred from the loading position to the working position (Figure 5).

[0037] The tube-holding carriage 16 is then advanced towards the tube T until the holding means 18 are brought into engagement with the trailing end TE of the tube (Figure 6).

[0038] At this point, according to an embodiment, the support device 14 is moved along the feed axis x towards the tube T, i.e., it is moved backward, until the leading end LE of the tube T intercepts the light beam L emitted by the transmitter 30 of the photoelectric sensor mounted on that support device 14 (Figures 7 and 8). Since at that time the axial position of the support device 14, and thus of the vertical transverse plane in which the light beam L emitted by the transmitter 30 lies, is known, the control unit of the apparatus 10 is able to determine the length of the tube T by difference between the axial position of the leading end LE and the axial position of the trailing end TE.

[0039] In the case where the support device 14 is stationary, instead of being movable along the feed axis x, or, more generally, in the case where the photoelectric sensor is mounted on a stationary component of the apparatus, the forward movement of the tube T controlled by the tube-holding carriage 16 will at some point cause the leading end LE of the tube T to intercept the light beam L emitted by the transmitter 30. By detecting at that time how far the tube-holding carriage 16 has been advanced from the position, shown in Figure 6, where the tube T has been held, and by knowing the axial position of the trailing end TE of the tube T, as well as the axial (fixed) position of the support device 14 (or, more generally, of the component of the apparatus on which the photoelectric sensor is mounted), and hence of the light beam L, the control unit is able to determine, again by difference between the axial position of the leading end LE and the axial position of the trailing end TE, the length of the tube T.

[0040] The present invention has been described herein with reference to one possible embodiment thereof. It is to be understood that other embodiments may be envisaged, which share the same inventive core with the one described herein, as defined by the appended claims.

Claims

CLAIMS1. Apparatus for processing tubes and profiles (T), comprising:- working means (12) arranged to carry out machining operations, such as cutting and / or welding operations, on a tube or profile (T);- holding means (16, 18) configured to hold the tube or profile (T) to be processed at a trailing end thereof (TE), opposite to a leading end (LE) of the tube or profile (T) facing said working means (12), and to cause the tube or profile (T) to be processed to move towards said working means (12), said holding means (16, 18) defining a feed axis (x) of the apparatus and comprising a tube-holding carriage (16) adapted to translate along said feed axis (x) between a maximum advance position, i.e., a position of minimum distance from said working means (12), and a maximum withdraw position, i.e., a position of maximum distance from said working means (12); and- loading means (20, 22) configured to support each time a tube or profile (T) to be processed in a loading position, in which the tube or profile (T) is arranged with its longitudinal axis parallel to, but at a distance from, the feed axis (x), and to transfer the tube or profile (T) from said loading position to a working position, in which the tube or profile (T) is arranged with its longitudinal axis aligned with the feed axis (x) to be held by said holding means (16, 18) and be caused to move forward along the feed axis (x) towards said working means (12); characterized in that it further comprises:- first sensor means (24) mounted on the tube-holding carriage (16) and configured to detect, as the tube-holding carriage (16) is moved backward along the feed axis (x) from said maximum advance position to said maximum withdraw position, with the tube or profile (T) placed in said loading position, a condition where said first sensor means (24) reach the trailing end (TE) of the tube or profile (T); and- a control unit arranged to control the translational movement of the tube-holding carriage (16) along the feed axis (x), said control unit being connected to said first sensor means (24) so as to be able to determine the position of the trailing end (TE) of the tube or profile (T) along the feed axis (x) based on signals provided by said first sensor means (24).

2. Apparatus according to claim 1 , wherein said first sensor means (24) are mounted on a side of the tube-holding carriage (16) facing the tube or profile (T), when the latter is placed in said loading position.

3. Apparatus according to claim 1 or claim 2, wherein said first sensor means (24) comprise a contactless sensor.

4. Apparatus according to claim 3, wherein said contactless sensor is a distance sensor, in particular a time-of-flight distance sensor.

5. Apparatus according to claim 3, wherein said contactless sensor is a proximity sensor.

6. Apparatus according to any one of claims 2 to 5, wherein said first sensor means (24) are mounted on an arm (26), which in turn is mounted on the tube-holding carriage (16) so as to move integrally therewith along the feed axis (x), and wherein the arm (26) is stationary or movable between an operating position, in which it projects laterally from the tube-holding carriage (16), and a non-operating position, in which it is retracted or folded away from said operating position.

7. Apparatus according to any one of the preceding claims, further comprising second sensor means (30, 32) which are mounted on a component (14) of the apparatus, in particular a component placed in the vicinity of said working means (12), and are configured to intercept the leading end (LE) of the tube or profile (T), as a result of the movement of the tube or profile (T) relative to said component (14) along the feed axis (x), and to provide a corresponding signal to the control unit.

8. Apparatus according to claim 7, wherein said second sensor means (30, 32) comprise a photoelectric sensor having a transmitter (30) and a receiver (32) which are mounted on said component (14), wherein the transmitter (30) is arranged to emit a light beam (L) directed to as to be intercepted by the leading end (LE) of the tube or profile (T) as a result of the movement of the tube or profile (T) relative to said component (14) along the feed axis (x), and wherein the receiver (32) is arranged to receive the light beam (L) emitted by the transmitter (30).

9. Apparatus according to claim 7 or claim 8, wherein said component (14) is a support device arranged to support the tube or profile (T) during processing, said support device being in particular mounted so as to be able to translate along the feed axis (x) to move along said axis under control of the control unit.

10. Apparatus according to any one of claims 7 to 9, wherein the control unit is configured to determine the length of the tube or profile (T) based on the signals provided by said first sensor means (24) and second sensor means (30, 32).

11. Method for determining the position of the trailing end (TE) of a tube or profile (T) to be processed in an apparatus for processing tubes and profiles (T) according to any one of the preceding claims, the method comprising the steps of:- moving the tube-holding carriage (16) along the feed axis (x) of the apparatus, with the tube or profile (T) placed in said loading position; and- while the tube-holding carriage (16) is being moved towards said maximum withdraw position, detecting by means of said first sensor means (24) the condition where said first sensor means (24) reach said trailing end (TE) of the tube or profile (T).

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