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Title:
BENDING MACHINE AND METHOD FOR BENDING A METAL SHEET USING SAID BENDING MACHINE
Document Type and Number:
WIPO Patent Application WO/2022/144651
Kind Code:
A1
Abstract:
A bending machine for bending metal sheets (2) comprises a lower roller (16), at least one side roller (18), and an upper roller (20). The upper roller (20) is coupled to an anti-bending beam (30). The anti-bending beam is rotatable about the rotation axis of the upper roller (20), with beam locking means (40) being provided which are suitable to lock the anti-bending beam in a desired angular position.

Inventors:
ARLIA FRANCO (IT)
Application Number:
PCT/IB2021/061617
Publication Date:
July 07, 2022
Filing Date:
December 13, 2021
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
FACCIN S P A (IT)
International Classes:
B21D5/14
Foreign References:
US3103965A1963-09-17
JPS5041758A1975-04-16
US8061172B22011-11-22
DE9305070U11994-08-04
Attorney, Agent or Firm:
CHIMINI, Francesco et al. (IT)
Download PDF:
Claims:
CLAIMS

1. A bending machine for bending metal sheets (2) , comprising a front support structure (22) and a rear support structure (24) supporting, in a rotatable manner about respective rotation axes (X, Y, Z) , a lower roller (16) , at least one side roller (18) , and an upper roller (20) , wherein the upper roller (20) is coupled to an anti-bending beam (30) constrained at the back to the rear support structure (24) and at the front to the front end of the upper roller (20) and/or to the front support structure (22) so as to oppose the bending to which the upper roller (20) is subjected, the bending machine being characterized in that said anti-bending beam is rotatable about the rotation axis of the upper roller (20) , the bending machine being provided with beam locking means (40) suitable to lock the anti-bending beam in a desired angular position.

2. A bending machine according to claim 1, wherein the anti-bending beam (30) extends along a beam axis (W) , the anti-bending beam being rotatable so that the plane on which the beam axis (W) and the rotation axis (Z) of the upper roller lie can be inclined with respect to the vertical position.

3. A bending machine according to claim 1 or 2, wherein one of the front support structure and the rear support structure is provided with a beam connection plate (50) configured to guide the anti-bending beam (30) in the rotation movement with respect to the upper roller (20) .

4. A bending machine according to claim 3, wherein the anti-bending beam (30) is provided, at one end thereof, with a counter-plate (32) suitable to abut against the beam connection plate (50) , the beam locking means (40) being suitable to tighten the connection plate (50) against the counter-plate (32) .

5. A machine according to claim 4, wherein the antibending beam (30) is retained in a desired angular position due to the friction between the counterplate (32) and the beam connection plate (50) , generated by the tightening of the beam locking means (40) .

6. A bending machine according to claim 4 or 5, wherein at least one circle arc groove (52) is obtained in the connection plate (50) , the locking means (40) being suitable to connect the connection plate (50) to the counter-plate (32) thus obtaining a shape coupling with the at least one groove (52) .

7. A bending machine according to claim 6, wherein the locking means comprise one or more locking blocks (42) inserted with shape coupling into the at least one groove (52) , the counter-plate being connected to said locking blocks by means of locking screws (44) . 15

8. A bending machine according to claim 7, wherein each groove and the locking blocks are "T"-shaped.

9. A bending machine according to any one of the preceding claims, wherein one end of the anti-bending beam is provided with an end flange (34) wherein a circular opening (36) rotatably engaged by one end of the upper roller (20) is obtained.

10. A bending machine according to any one of the preceding claims, wherein backing rollers (56) are installed in a lower part of the anti-bending beam (30) , coming into contact with the upper roller (20) so as to stiffen the upper roller (20) with rotation freedom.

11. A bending machine according to the preceding claim, wherein the backing rollers (56) are adjustable so as to vary the position of contact with the upper roller (20) for adjusting the bending control effect of the upper roller (20) .

12. A method for bending a metal sheet by means of a bending machine according to any one of the preceding claims, comprising the steps of: loosening the locking means so as to allow the adjustment of the angular position of the anti-bending beam;

- based on the curvature radius to be given to the metal sheet and/or to the thickness of the metal sheet and/or 16 to the elastic return of the metal sheet , positioning the anti-bending beam in an angular position selected so as not to interfere with the bent metal sheet ;

- tightening the locking means so as to lock the anti- bending beam in the selected angular position;

- operating the bending machine .

13 . A method according to the preceding claim, wherein the anti-bending beam is rotated towards the inlet side of the metal sheet in the machine .

Description:
BENDING MACHINE AND METHOD FOR BENDING A METAL SHEET USING SAID BENDING MACHINE

DESCRIPTION

[0001] This invention relates to a bending machine for bending metal sheets .

[0002] As is known, bending machines for bending metal sheets are machine tools in the family of calenders , and are particularly suitable for forming tubes from metal sheets having various thicknesses .

[0003] A bending machine generally comprises two or more rollers through which a planar metal sheet is passed; the rollers are arranged so as to deform the metal sheet by bending it along a predetermined curvature radius .

[0004] This invention relates in particular to bending machines having at least one lower roller, at least one side roller, and an upper roller, with the rollers being rotatable about respective hori zontal rotation axes .

[0005] In order to obtain reduced curvature radii , with the same thickness of the metal sheet , the diameter of the upper roller is reduced . Since a roller having a reduced diameter is not able to support the bending load, it is known to install an anti-bending beam suitable to contain the bending of the roller within the limits necessary for correct bending of the metal sheet .

[0006] Nevertheless , whilst allowing upper rollers having a limited diameter to be used, the presence of the anti- bending beam also constitutes an obstacle which interferes with the metal sheet exiting the rollers , in fact preventing the metal sheets from being bent with particularly reduced curvature radii .

[0007] The obj ect of this invention is to provide a bending machine capable of bending metal sheets with very small curvature radii .

[0008] In particular, the invention is intended to allow a machine of this kind to widen the range of calenderable metal sheets .

[0009] These obj ects are achieved by means of a bending machine according to claim 1 and by means of a method for bending a metal sheet according to claim 12 . The dependent claims describe preferred or advantageous embodiments of the bending machine .

[0010] The features and advantages of the bending machine according to the invention will become apparent from the following detailed description of its preferred embodiments , given by way of non-limiting example , with reference to the accompanying figures , in which :

[0011] - Fig . 1 is a perspective view of a bending machine according to this invention, with the antibending beam in an inclined position with respect to the vertical ;

[0012] - Fig . 2 is a perspective view of the machine in Fig . 1 , with the anti-bending beam in a vertical position;

[0013] - Fig . 3 shows an enlarged detail of the machine in Fig . 1 , at the anti-bending beam;

[0014] - Fig . 4 is a view analogous to Fig . 3 , but with the anti-bending beam separated from the machine ;

[0015] - Fig . 5 is a perspective view of an end portion of the anti-bending beam and the means for fixing said beam to the machine ;

[0016] - Fig . 6 is an end view of the machine , without the front support structure , with the anti-bending beam inclined, and during bending of a metal sheet ; and

[0017] - Fig . 7 is a view analogous to the preceding figure , with the anti-bending beam in a vertical position .

[0018] In said drawings , the reference sign 1 is used to indicate a bending machine according to the invention as a whole . The bending machine 1 is suitable in particular to bend a metal sheet 2 .

[0019] The bending machine 1 generally comprises a machine body 10 which extends mainly hori zontally and has a base 12 for standing on the ground .

[0020] The machine body 10 is configured so as to form a support structure 14 for a plurality of deformation rollers . In particular, the machine 1 is provided with a lower roller 16 , at least one side roller 18 , and an upper roller 20 , which rollers are supported at the ends by a front support structure 22 and by a rear support structure 24 . The rollers 16 , 18 , 20 are supported so as to be able to rotate about respective rotation axes X, Y, Z . In one embodiment , the rotation axes X, Y and Z are hori zontal axes . Nevertheless , in some embodiments , the rotation axes X and Y of the lower and side rollers are inclined axes for carrying out calendering of conical shells .

[0021] In the context of the present description, the terms " front" and "rear" are merely used to distinguish the two support structures for the rollers with reference to the orientation of the machine shown in the accompanying drawings , but are considered to be interchangeable .

[0022] One of the two support structures , which in the example shown is the rear support structure 24 , is formed in a portion 26 for controlling the machine body 10 , in which portion the electrical , mechanical and electronic components responsible for operating and controlling the rollers are housed .

[0023] The general structure of the machine 1 and its functional components is of a kind generally known to a person skilled in the art and does not require more detailed explanation . [0024] In one embodiment , the upper roller rotation axis Z and the lower roller rotation axis X lie on a vertical plane .

[0025] The term " side rollers" 18 refers to the rollers positioned on either side of the lower roller 16 and upper roller 20 , for engaging with the metal sheet entering ( input side roller ) and/or exiting ( output side roller ) the machine . The side rollers are movable with respect to the lower and upper rollers between a lowered position and a raised position in order to assist in bending the metal sheet , by acting thereon individually and in combination with the lower and upper rollers during the various steps of creating the shell , as shown in Fig . 6 and 7 .

[0026] In one embodiment , the upper roller 20 has a particularly small diameter, so as to allow bending with reduced radii of curvature . For example , in some embodiments , the upper roller 20 has a smaller diameter than the diameter of all or at least some of the other rollers .

[0027] The upper roller 20 is coupled to an anti-bending beam 30 suitable to oppose the bending to which the upper roller 20 is subj ected .

[0028] At the back, the anti-bending beam 30 is constrained to the rear support structure 24 . [0029] At the front , the anti-bending beam 30 can be constrained to the upper roller 20 . In some embodiments , the anti-bending beam 30 can be constrained at the front only to the front support structure 22 or to both the upper roller 20 and the front support structure 22 , depending on requirements .

[0030] According to one aspect of the invention, the antibending beam 30 is rotatable about the rotation axis Z of the upper roller 20 . Moreover, the bending machine 1 is provided with beam locking means 40 suitable for locking the anti-bending beam 30 in a desired angular position .

[0031] In particular, the anti-bending beam 30 extends mainly along a beam axis W parallel to the rotation axis Z of the upper rol ler 20 . In some embodiments , as shown in the drawings , the anti-bending beam 30 extends symmetrically with respect to a beam plane P . In other embodiments , the anti-bending beam 30 can also be asymmetrical .

[0032] When the anti-bending beam 30 is in a neutral vertical position ( Fig . 7 ) , the beam plane P is a vertical plane .

[0033] The anti-bending beam 30 is rotatable such that the plane on which the beam axis W and the rotation axis Z of the upper roller 20 lie can be inclined with respect to the vertical position, as shown in Fig . 1 , 3 and 6 . In other words , the anti-bending beam 30 is rotatable about the upper roller 20 such that the beam plane P assumes an inclined position with respect to the vertical ( Fig . 6 ) . [0034] In one embodiment , the upper roller 20 is provided, at the two opposite ends thereof , with bearings which allow the roller to rotate . For example , these bearings can be rolling-element bearings or plain bearings . One or more rear bearings (not shown) can be housed in the rear support structure 24 .

[0035] In one embodiment , the front support structure 22 comprises a movable part 22 ' suitable to be opened to allow the finished product to be removed from the machine .

[0036] The front bearing or bearings 54 can be fixed to the front end of the upper roller or can be housed in the movable part 22 ' of the front support structure 22 .

[0037] The anti-bending beam 30 is fixed to the rear support structure 24 as will be described below .

[0038] Backing rollers 56 ( shown in Fig . 6 and 7 ) are installed in the lower part of the anti-bending beam 30 . These backing rollers 56 come into contact with the upper roller 20 so as to provide support for the upper roller 20 , thus allowing it to rotate . The rigidity of the anti-bending beam 30 is added to that of the upper roller 20 , which is thus increased . [0039] In one embodiment , the backing rollers 56 can be adj usted so as to vary the position of contact with the upper roller 20 and thus more or less contain the bending thereof as needed . In other embodiments , the backing rollers 56 are fixed in position .

[0040] In one embodiment , one of the front support structure 22 and the rear support structure 24 ( in the example shown, the rear support structure 24 ) is provided with a beam connection plate 50 configured to guide the beam 30 in the rotational movement with respect to the upper roller 20 .

[0041] For example , the anti-bending beam 30 can rotate between an angle of +30 ° and -30 ° with respect to the vertical position .

[0042] In one embodiment , at least one circle arc groove 52 is made in the beam connection plate 50 . The anti-bending beam 30 is provided, at one end thereof , with a counterplate 32 . The locking means 40 are suitable to connect the connection plate 50 to the counter-plate 32 , thus obtaining a shape coupling with the groove ( s ) 52 .

[0043] In one embodiment , the locking means 40 comprise one or more locking blocks 42 inserted with shape coupling into the grooves 52 . The counter-plate 32 is connected to the locking blocks 42 by means of locking screws 44 . The beam 30 is retained in a desired angular position due to the friction between the counter-plate 32 and the connection plate 50 , which friction is generated by the tightening of the locking screws 44 .

[0044] In one embodiment , each groove 52 and the locking blocks 42 are "T"-shaped .

[0045] In the embodiment shown in the drawings , two concentric grooves 52 are made in the beam connection plate 50 , into each of which grooves two blocks 42 are inserted . This facilitates the rotation of the antibending beam when the locking means are released, and ensures the stability and rigidity of the beam once the locking means are operated .

[0046] In one embodiment , one end of the anti-bending beam 30 - the end opposite the counter-plate 32 - is provided with an end flange 34 in which a circular opening 36 engaged by one end of the upper roller 20 is made . One or more rolling-element or plain bearings 54 can be housed in the circular opening 36 in the end flange 34 , which bearings allow the anti-bending beam 30 to be constrained to the upper roller 20 so as to allow said roller to rotate and at the same time rigidly secure it to the beam in order to contain the bending .

[0047] This invention also relates to a method for bending a metal sheet 2 by means of a bending machine 1 as described above . [0048] The method comprises the following steps :

[0049] - loosening the locking means 40 , for example by unscrewing the locking screws 44 , so as to allow the angular position of the anti-bending beam 30 to be adj usted;

[0050] - based on the curvature radius to be given to the metal sheet 2 and/or the thickness of the metal sheet 2 and/or the elastic return thereof , positioning the antibending beam 30 in an angular position selected so as not to interfere with the bent metal sheet ;

[0051] - tightening the locking means 40 so as to lock the anti-bending beam in the selected angular position;

[0052] - operating the bending machine 1 .

[0053] In particular, the anti-bending beam 30 is rotated toward the side on which the metal sheet enters the machine ( Fig . 6 ) .

[0054] In one embodiment , the anti-bending beam can be oriented manually, for example by means of an overhead crane .

[0055] Fig . 6 shows an anti-bending beam inclined to allow a metal sheet to be deformed with a minimum curvature radius , which it is not possible to achieve with a beam in a vertical position as a result of the interference with the metal sheet . This setting is particularly advantageous for allowing the bending of thin thicknesses of steels having a high elastic return with minimum bending radii .

[0056] In the example in Fig . 7 , the anti-bending beam 30 is placed in a vertical position . In this case , it is possible to bend greater thicknesses than with the inclined position of the beam, because it is possible to exploit the symmetrical thrust of the side rollers 18 ; the elastic return of the metal sheet reduces as the thickness increases , and therefore , with this setting, it is possible to bend metal sheets having a greater thickness with minimum diameters , close to those which can be obtained using the beam inclined as in Fig . 6 .

[0057] Therefore , from time to time , the operator can orient the anti-bending beam into the optimal position in order to allow a wide range of metal sheets to be bent .

[0058] By comparison with a traditional machine , which has an anti-bending beam that has a fixed orientation, the machine according to the invention makes it possible to rotate the position of the beam at di f ferent angles , so as to allow said machine to widen the range of calenderable metal sheets with optimal results .

[0059] It is also possible , depending on this setting, to insert the metal sheet to be calendered from both the right-hand and left-hand side of the machine .

[0060] In order to meet contingent needs , a person skilled in the art may make a number of changes , adaptations and replacements of elements with other functionally equivalent ones to the embodiments of the bending machine according to the invention, without departing from the scope of the following claims . Each of the features described as belonging to a possible embodiment may be obtained independently of the other described embodiments .