Roll forming machine

Abstract

Roll forming machine with a plurality of aligned heads (4), each equipped with an upper shaft (18') and a lower shaft (18) counter-rotating to support rollers (20', 20) shaped in accordance with different profiles to be reproduced on a sheet of metal passed between all said heads (4), characterised in that said aligned heads (4) are functionally grouped in a plurality of profiling groups, configured to make said sheet of metal assume different profiles, each obtained with one of said profiling groups, and that the shafts (18, 18') of each head (4) are supported at the ends by a pair of slides (16, 16') mounted on shoulders (8), along which said slides (16, 16') are movable to bring said shafts (18, 18') closer to or further away from each other with the respective rollers (20, 20') so as to keep the rollers of the heads belonging to the same profiling group in an active position, interfering with said sheet metal, and the rollers of the heads belonging to all the other profiling groups in an inactive position, not interfering with said sheet metal.

Description

[0001] ROLL FORMING MACHINE.

[0002] The present invention relates to a roll forming machine.

[0003] Roll forming machines are well-known, consisting of machines designed to impress a series of longitudinal folds on a strip or sheet of metal to transform its flat profile into a different profile, suitable for particular uses, for example for creating building roofs or cladding for building facades.

[0004] These well-known roll forming machines comprise a bed, on which roll forming heads can be mounted. These heads consist of pairs of vertical frames, each pair supporting two horizontal shafts, one upper and one lower, on which roll forming rollers are mounted. These roll forming rollers have essentially complementary shapes, creating a gap between them for the passage of the sheet metal to be rolled. As the sheet metal passes between successive roll forming heads, each equipped with a pair of rollers of specially complementary shapes, the sheet metal is progressively shaped from its initial flat state to the desired final profile.

[0005] Obviously, as the final profile to be obtained varies, the sequence of folds that must be induced on the sheet metal varies and therefore the shape of the rollers mounted on the individual profiling heads varies.

[0006] It follows that if one has to switch from the production of a certain profile, for which a certain series of profiling heads is used, to a different profile, all the pairs of rollers of the various profiling heads generally have to be replaced. This requires a series of lengthy and laborious interventions, which lead to significant downtime of the profiling line and production losses.

[0007] In an attempt to reduce these machine downtimes, it has been suggested to equip the profiling machine with multiple profiling groups, i.e. , multiple sets of profiling heads, each equipped with shafts with rollers of different shapes: the heads of one profiling group are put into operational condition while the heads of the other profiling groups are kept temporarily inactive but can be quickly replaced with the operational ones to be able to produce a different profile on the sheet metal.

[0008] A well-known profiling machine comprises a plurality of heads belonging to different profiling groups, arranged side by side and capable of moving laterally with respect to the profiling direction to be moved from an operating position to an inactive position and vice versa. It is clear that to produce a certain profile, it is sufficient to move only the heads of the profiling group configured to produce that profile into an operating condition, leaving in an inactive condition all the heads of the other groups. This solution implies a significant lateral encumbrance of the profiling machine, as it requires a suitable space next to the profiling line itself to accommodate the heads that are not used to produce that particular profile.

[0009] Another known solution, described for example in JPS59159224, comprises a plurality of profiling head groups mounted on turrets rotating around a horizontal axis parallel to the longitudinal axis of the profiling machine and equipped with rollers configured to produce different profiles. In each position of the rotating turrets, one profiling head is operational while the other heads are inactive, i.e. , not in the profiling line.

[0010] This solution has made it possible to speed up the replacement operations of the profiling heads but involves considerable construction complexity as well as a significant vertical bulk of the machine.

[0011] Another well-known solution, described for example in EP 2127773, involves mounting a plurality of profiling heads, corresponding to the different profiles to be produced, on vertical structures, along which the individual heads can slide vertically to move from an intermediate operating position to extreme non-operating positions. This is a simpler solution from a construction standpoint but is more cumbersome from a vertical sense.

[0012] Another well-known solution involves using multiple profiling heads, in which the profiling heads belonging to the various groups are mounted in a fixed, overlapping configuration, thus defining profiling lines positioned at different levels, which can be selected based on the specific profile to be achieved. This is a simpler solution from a construction standpoint, as it does not require the movement of the different profiling heads, but it does require significant height space for the profiling lines and requires the sheet metal to be entered and the profiles to be exited at different levels, requiring adjustment of the heights of the machines preceding and following the roll forming machine.

[0013] US 4109499 describes a profiling line with multiple heads configured to operate on the same strip to be profiled; the heads are equipped with actuators that ensure a substantially constant pressure of the profiling rollers on the strip itself, regardless of possible variations in its thickness. This line does not provide any possibility of modifying the desired profile without having to intervene on the profiling heads to replace the rollers mounted on them.

[0014] The aim of the invention is to propose a roll forming machine that eliminates all the drawbacks recognisable in the traditional roll forming machines now referred to. In particular, the aim of the invention is to propose a roll forming machine in which the time required to configure the machine to produce a certain profile and to reconfigure it when it is necessary to produce a different profile is reduced.

[0015] Another aim of the invention is to propose a roll forming machine in which the lateral space required is limited to that required by the operating profiling heads only.

[0016] Another aim of the invention is to propose a roll forming machine, in which the overall dimensions are also limited in height.

[0017] Another aim of the invention is to propose a roll forming machine that can be obtained by modifying existing roll forming machines.

[0018] All these aims and others that will result from the following description can be achieved either jointly or separately with a roll forming machine as defined in claim 1.

[0019] The present invention is further clarified below in some of its preferred forms of practical embodiment, reported for purely illustrative and non-limiting purposes with reference to the attached tables of drawings in which:

[0020] Figure 1 shows a schematic side view of a roll forming machine according to the invention,

[0021] Figure 2 shows it in plan.

[0022] Figure 3 shows a side view and a larger scale of a portion of a cassette with three profiling heads belonging to two different profiling groups, Figure 4 shows it partially according to the front view IV - IV of Fig. 3,

[0023] Figure 5 shows a schematic front view from the input side of a cassette designed to produce a wavy profile,

[0024] Figure 6 shows it in the same view but from the exit side,

[0025] Figure 7 shows it in the same view as Fig. 5 but designed to produce a corrugated profile,

[0026] Figure 8 shows it in the same view as Fig. 6 but designrd to produce a corrugated profile,

[0027] Figures 9a - 9c show a schematic side view of a shoulder in three different conditions of mutual approach of the slides that support the profiling rollers and which are moved by a toggle mechanism, and

[0028] Figure 10 shows a partial perspective view of a pair of profiling rollers supported by a shoulder equipped with a device for fine adjustment of the distance between the rollers themselves.

[0029] As shown in the figures, the roll forming machine according to the invention comprises a bed 2, on which a plurality of profiling heads 4 are mounted, divided into profiling groups, each configured to obtain a well-defined profile. The heads 4 can be mounted directly on the bed 2 or, preferably, as illustrated in the drawings, they can be grouped into “boxes” or “sets” or “cassettes” 6, to be mounted on the bed 2 of the machine. In this case, the heads belonging to the same profiling group can be mounted on a single cassette or can also be distributed across multiple cassettes.

[0030] The following description will refer to a single cassette 6, on which heads belonging to multiple profiling groups are mounted, but the same description must be understood to extend to all the other cassettes 6 mounted or to be mounted on the bed 2 of the profiling machine as well as to profiling heads 4 mounted directly on the bed 2.

[0031] Each profiling head 4 mounted on a cassette 6 comprises a pair of shoulders 8, which in practice consist of substantially rigid vertical structures fixed on a plate 10, which forms the base of the cassette 6 and which is intended to be fixed to the bed 2 of the machine.

[0032] Each shoulder 8 comprises a pair of uprights 12, for example each consisting of two sturdy vertical cylindrical bars secured at the ends to two plates, a lower one 14, and an upper one 14', in turn fixed to the base 10 of the box 6. However, different types of shoulders can also be envisaged, with different uprights, but still known in themselves.

[0033] Along each upright 12, two slides 16,16' can slide to support the ends of two shafts 18,18', on which the profiling rollers 20,20' for that profiling head 4 are mounted.

[0034] Both slides 16,16' of each pair of uprights 12 are movable along the uprights themselves and their stroke is significantly greater than the usual stroke to which the profiling rollers are generally subjected during process adjustments.

[0035] One end of the lower shaft 18 is connected to the lower slide 16 of each shoulder 8, and this lower shaft 18 supports the lower roller 20 of the pair of rollers of that profiling head 4, while one end of the upper shaft 18' is connected to the upper slide 16', and this upper shaft 18’ supports the upper roller 20' of the same pair of rollers of that profiling head.

[0036] Both slides 16,16' can slide along the vertical uprights 12 and in particular can move between a closer relative position (active position), at which the respective rollers 20,20' delimit between them a slot of a thickness substantially corresponding to the thickness of the sheet metal to be profiled, and a more distant relative position (inactive position), at which the respective rollers 20,20' do not interfere with the sheet metal that passes between them and which is subjected to be profiled by rollers mounted on heads 4 belonging to other profiling groups. Figures 5 and 6 show two aligned profiling heads in two opposing front views; one profiling head belongs to a profiling group, is in the active position and is equipped with profiling rollers 20,20' configured to form a wavy profile, while the other profiling head belongs to a different profiling group, is in the inactive position and is equipped with rollers configured to form a corrugated profile; Figures 7 and 8 instead show the same profiling heads with the same profiling rollers but in the reversed condition, that is, with the head equipped with rollers configured to produce a wavy profile in the inactive position and with the head equipped with rollers configured to produce a corrugated profile in the active position.

[0037] The movement of the slides 16,16' along the uprights 12 can be achieved using various techniques. One of these involves the two slides 16,16' of each shoulder 8 being simultaneously engaged in two counter-threaded portions of the same vertical shaft 22, driven into rotation by an electric, electromechanical, or other type of actuator. It is clear that the rotation of the shaft 22 in either direction causes the two slides 16,16' to move closer or further away from each other. If the shafts 22 provided with counter-threaded portions belonging to each head are then connected to each other, for example mechanically, the actuation of a single actuator involves the simultaneous and opposing movement of the slides 16,16' of both pairs of that head and essentially the simultaneous and opposing translational movement of the two shafts 18, 18' and of the two rollers 20,20' of this.

[0038] It is also envisaged that the drive shafts 22 of the slides 16, 16' of all the heads 4 to be made active for producing a certain profile are connected to each other, and can be controlled by a single motor, so that they all pass simultaneously from an active position to an inactive position and vice versa. However, in the case in which the heads 4 are mounted on cassettes 6, the connection between the shafts with threaded portions to be connected simultaneously concerns only the heads of that cassette or the heads of all the cassettes.

[0039] Another way to control the opposing movement of the two pairs of slides 16,16' each head 4 or of all the heads can be obtained with hydraulic actuators coupled directly with the two slides 16,16' sliding along the respective shoulder 8.

[0040] Yet another way can be achieved with toggle mechanism, also coupled with the two slides 16,16' sliding along each shoulder 8.

[0041] Figures 9a - 9c schematically illustrate a shoulder 8 of a profiling head 6 in three successive phases, in which a toggle mechanism operated by an actuator 26 moves the two slides 16,16' from the inactive position (fig. 9a) to the active position (fig. 9c), passing through an intermediate position (fig. 9b). In particular, the toggle mechanism comprises a pair of rods 24,24' articulated together by command of the actuator 26 and capable of switching from an angled configuration, corresponding to the inactive position of the profiling rollers 20,20 ', to an aligned configuration, corresponding to the active position of the profiling rollers. One of the two rods 24' is also articulated to a plate 28 that slides along the shoulder 8, while the other rod 24 is also articulated to the upper ram 16', which is crossed by two vertical tie rods 30, having the upper end fixed to the plate 28 and the lower end fixed to the lower ram 16.

[0042] The movement of the two slides 16,16' to pass from the inactive position to the active position involves extending the actuator 26, so as to bring the two rods 24,24' of the toggle mechanism from the angled configuration illustrated in fig. 9a to the substantially aligned configuration illustrated in fig. 9b. More specifically, in fig. 9a the two slides 16,16' are seen further apart from each other (inactive position); following the extension of the actuator 26, the two rods 24,24' of the toggle mechanism tend to move to the aligned configuration, with a first phase, in which the upper slide 16' begins to descend along the respective upright 12 until it reaches the end-of-travel stops 32 (fig. 9b). The continuation of the extension stroke of the actuator 26 then causes the upward movement of the plate 28 and of the two tie rods 30 fixed to it and the consequent upward dragging of the lower slide 16 until it reaches the active position (fig. 9c).

[0043] Once all the heads belonging to a profiling group have been adjusted to the active position, while all the heads of the other profiling groups are kept in the inactive position, the flat strip to be profiled is passed through the subsequent heads of that profiling group and subjected to the subsequent profiling phases. In order to uniformly distribute the sequence of bends induced on the sheet metal to implement the profiling process, it is preferable for the profiling heads 4 to be interspersed with each other, meaning that the inactive heads are always in intermediate positions with respect to the active heads. For example, if nine heads belonging to three different profiling groups are mounted in a cassette, i.e., configured to produce three different profiles, it is preferable that the first head 4, configured to produce the first profile, is followed by the first head, configured to produce the second profile, and then by the first head configured to produce the third profile, and then by the second head to produce the first profile, and so on.

[0044] If more cassettes 6 are mounted on the bed 2 of the profiling machine, each equipped with heads for producing different profiles, the machine itself can be suitably set up to bring the heads belonging to the various cassettes into active position and configured to produce that profile, leaving all the other heads in inactive position.

[0045] In addition to being able to adjust the individual profiling heads 4 so as to make them pass individually from an active position to an inactive position, the individual heads must be motorized, in the sense that the rollers 20,20' of at least the active head must be able to rotate in the opposite direction to advance the sheet metal and at the same time to impress longitudinal folds as it passes in accordance with the desired profile to be obtained.

[0046] Even the motorization of the heads, which is preferably obtained with electric motors, can be implemented in various ways.

[0047] One of these involves keeping all the rollers constantly rotating, both those of the active and inactive heads. This simplifies the machine's construction, allows for the use of a single motor, and eliminates the need for any device to selectively connect the motor to the rollers of the heads to be driven. At the same time, simultaneously driving all the heads, even the inactive ones, can result in unnecessary energy waste and wear on components left running idle.

[0048] Another possible way to motorize the profiling machine involves operating only the heads that need to be made operative: this obviously results in more limited energy consumption and less wear on components but requires separate motors to operate the different groups of heads that form the different profiles.

[0049] Finally, another possible way to motorize the roll forming machine involves equipping the individual heads with individual motors, which in this case can have more limited power and do not require mechanical connections between the various heads that must be operated simultaneously, but obviously they must be in equal number to the number of heads and require a synchronization system to ensure the correct advancement of the sheet metal being profiled.

[0050] Figures 1 and 2 illustrate, by way of example, a roll forming machine with four cassettes 6, each of which has nine profiling heads 4 mounted on it, belonging to two different profiling groups. The shafts 18,18' of all the profiling heads 4 belonging to the same profiling group are mechanically connected to each other and can be interchangeably connected via gear units 34 and universal joints 36 to a single shaft 38 driven by a single electric motor 40.

[0051] In addition to the motorization system for the profiling heads 4, the machine according to the invention also includes a system for fine-tuning the relative position of the rollers 20, 20' of each head 4 based on the thickness of the sheet metal to be profiled. This requires small translational movements of the shafts 18, 8', on which the profiling rollers 20,20' are mounted. These small movements can be performed manually on the individual head 4 or automatically both on the individual head 4 and all the heads configured to produce a given profile.

[0052] An advantageous fine adjustment system is illustrated in detail in Fig. 10. It provides that one of the two slides, for example the upper slide 16', has a toothed wheel 42 attached to it, axially constrained to the slide itself but free to rotate with respect to it. The toothed wheel 42 is coupled to a horizontal rack 44 which can move axially under the control of an adjustment screw 46.

[0053] The gear wheel 42 is engaged with its internal thread with the threaded shaft 22, so that the rotation of the screw 46 causes the axial movement of the rack 44, the rotation of the gear wheel 40 and the small vertical adjustment movements of the upper slide 16' and therefore of the position of the upper profiling roller 20' with respect to the lower roller 20.

[0054] In any case, regardless of the motorization system of the profiling heads 4 and the fine adjustment system of the distance between the profiling rollers 20,20' of each head 4, the roll forming machine according to the invention is more advantageous than traditional roll forming machines and in particular:

[0055] - allows you to configure the machine to produce one or other of the various profiles it is capable of producing, with simple and rapid maneuvers that involve very limited production downtime,

[0056] - it requires a lateral and height encumbrance substantially equal to that required by the operating heads alone,

[0057] - can be obtained from a traditional cassette roll forming machine by simply replacing the cassettes.

Claims

C L A I M S1. Roll forming machine with a plurality of aligned heads (4), each equipped with an upper shaft (18') and a lower shaft (18) counter-rotating to support rollers (20', 20) shaped in accordance with different profiles to be reproduced on a sheet of metal passed between all said heads (4), characterised in that said aligned heads (4) are functionally grouped in a plurality of profiling groups, configured to make said sheet of metal assume different profiles, each obtained with one of said profiling groups, and that the shafts (18,18') of each head (4) are supported at the ends by a pair of slides (16,16') mounted on shoulders (8), along which said slides (16,16') are movable to bring said shafts (18,18') closer to or further away from each other with the respective rollers (20,20') so as to keep the rollers of the heads belonging to the same profiling group in an active position, interfering with said sheet metal, and the rollers of the heads belonging to all the other profiling groups in an inactive position, not interfering with said sheet metal.

2. Roll forming machine according to claim 1 characterised in that the heads (4) belonging to each profiling group are interspersed with heads belonging to another profiling group or to other profiling groups.

3. Roll forming machine according to claim 1 and / or 2 characterised by comprising a bed (2), on which at least one cassette (6) is interchangeably mounted, said bed (2) comprising a base plate (10) to be secured to said bed (2) and a plurality of heads (4, 4', 4”) belonging to different profiling groups and configured to create different types of profiles.

4. Roll forming machine according to one or more of the preceding claims characterised in that each head (4) is provided with at least one vertical shaft (22) having two sections threaded in opposite directions and engaged by the two slides (16,16') supporting the upper shaft (18') and the lower shaft (18) of the head itself (4), said vertical shaft being associated with means for its rotation in both directions.

5. Roller profiling machine according to one or more of claims 1 to 3 characterised in that the two slides (16,16') of both shoulders (8) of each head (4) are mechanically constrained to the two mutually movable parts of a hydraulic actuator for the simultaneous movement in opposite directions of said slides (16,16') along the respective shoulders (8).

6. Roll forming machine according to one or more of claims 1 to 3 characterised in that the two slides (16,16') of both shoulders (8) of each head (4) are mechanically associated with a toggle mechanism for the movement in opposite directions of said slides (16,16') along the respective shoulder (8).

7. Roll forming machine according to claim 6, characterised in that said toggle mechanism comprises a pair of rods (24,24') articulated together and operated in their articulated movements by an actuator (26), one (24') of said rods being articulated to a first slide (16') of said pair of slides (16,16'), which is crossed by at least one tie rod (30) fixed with one end to the second slide (16) of the pair and with the other end to an element (28) sliding along the relative shoulder (8) and articulated with the other rod (24) of the toggle mechanism, the whole being configured in such a way that the extension of said rods (24,24') operated by said actuator (26) first causes the stroke of said first slide (16') towards said active position, defined by a mechanical stop (32) and then the recall of said second slide (16) towards said active position.

8. Roll forming machine according to one or more of claims 1 to 3 characterised in that the two slides (16,16') of both shoulders (8) of each head (4) are mechanically constrained to two parallel racks coupled at diametrically opposite points to the same toothed wheel which can be rotated in both directions.

9. Roll forming machine according to one or more of claims 4 to 8 characterised by comprising means for synchronising the movements of the slides (16,16') of all the heads (4) mounted on the same cassette (6) and / or belonging to the same profiling group.

10. Roll forming machine according to one or more of claims 4 to 9 characterised in that it comprises means for driving the shafts (18,18') of all the heads (4) belonging to the same profiling group and a single motor interchangeably connectable to said driving means relating to the different profiling groups.

11. Roll forming machine according to one or more of the preceding claims characterised in that each head (4) is provided with means for fine adjustment of the distance between the profiling rollers (20,20') which are in the active position, and that said fine adjustment means comprise a toothed wheel (42) axially constrained to one of said slides (16,16') but free to rotate with respect to it, said toothed wheel (42) being externally coupled with a rack (44) controlled by an adjustment screw (46) and being internally threaded and coupled with said threaded shaft (22),12. Roll forming machine according to one or more of the preceding claims characterised in that it comprises a plurality of electric motors associated with the individual profiling heads (4, 4', 4”).

13. Roll forming machine according to one or more of claims 1 to 11 characterised in that it comprises a single electric motor (36) for simultaneously driving the rollers (20,20') of all the profiling heads (4, 4', 4”).

14. Roller profiling machine according to claim 13 characterised by comprising a single electric motor (36) coupled via a single shaft (38) to gear units (34), in turn coupled via universal joints (36) to the shafts (18.18') of all the profiling heads (4, 4', 4”).

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