[0001] The present invention refers to a machine for the production of metal sheet panels
with bent edges, commonly referred to as panel machine.
[0002] In particular the invention refers to a panel machine equipped with a single bending
die to obtain metal sheets of generically rectangular shape having edges that are
bent one or more times at one or more of their four sides, for example of the kind
described in the Italian patent N. 1086365.
[0003] Panels of this type have a wide utilisation for example in the manufacture of metal
cabinets, refrigerators, washing machines, air conditioners, shelving in general etc.
[0004] The known panel machines comprise a work plane where to lay the metal sheet (panel)
to be machined, a bending press provided with a bending die and located frontally
to the work plane, a mechanical hand mobile with respect to the work plane to move
the sheet to be machined during machining, an automatic sheet feeder located laterally
to the work plane and comprising a carriage for the conveyance of the sheet from the
feeder to the work plane and for the removal of the bent sheet from the work plane
once the machining has been completed.
[0005] The conveyor carriage takes the sheet from the feeder and locates it on the work
plane; the mechanical hand takes the sheet substantially at its centre and it moves
it in such a way so as to position in turn each side to be bent in correspondence
of the bending press. Once the machining is completed, the mechanical hand drops the
sheet, and the carriage removes it from the work plane.
[0006] Therefore, all the operations of the panel machine, in particular the feeding of
the sheet to be machined and the removal of the machined sheet, are automated.
[0007] Because of the presence of the feeder and of the carriage, the machining zone (that
is the work plane) is substantially accessible from the outside during machining,
in order not to hinder the operations of the same carriage.
[0008] In order to meet the safety requirements imposed by the current regulations, light
scan devices (laser scanner or photocells) are provided which stop the panel machine
any time a human operator, or in any case a not identified body, gets near the machining
zone.
[0009] Such panel machines, although they are very efficient, are rather complex to realise
and as a consequence they are costly due exactly to the high degree of automation.
[0010] JP-A-04 046 644 discloses a sheet panel bending machine having a work plane.
[0011] US-A-4 863 320 discloses a machine tool wherein the work plane is enclosed inside
a protection structure comprising means for the interdiction of the access to the
work plane during machining.
[0012] In view of the state of the art described, object of the present invention is to
provide for a less complex and as a consequence less costly panel machine and that
would anyhow meet the safety requirement imposed by the current regulations.
[0013] According to the present invention, such object is obtained by means of a panel machine
as defined is claim 1.
[0014] According to a preferred form of embodiment, said interdiction means consist of a
door mounted on the protection structure in correspondence of the access opening or
openings, selectively openable by the human operator for the feeding and removal of
the sheet and closable during the machining of the same sheet. The door or doors form
physical barriers preventing the access to the work plane when the machine is operating.
[0015] As an alternative, said interdiction means can consist in light scan devices as photocells
or laser scanners, serving the purpose to interrupt the operation of the machine any
time that, during machining, a non-recognisable body tries to accede to the work plane
through the access door or doors.
[0016] The panel machine according to the invention is clearly less complex than the known
panel machines, since neither automatic feeder nor carriage to convey sheets are provided.
As a result of this, not only the panel machine is less costly, but it is also possible
to enclose the work plane inside a protection structure (physical), consisting for
example of a barrier made of sheets preferably provided with windows, that would completely
isolate the machining zone for the metal sheets from the outside during the same machining.
The feeding and removal of sheets from the work plane is carried out through the access
opening or openings provided in the protection structure by means of a human operator.
The presence of said interdiction devices in correspondence of the access opening
or openings guarantees the safety of the operator.
[0017] The characteristics and advantages of the present invention will be rendered more
evident by the following detailed description of a possible embodiment thereof, illustrated
as a non-limiting example in the enclosed drawings, in which:
Figure 1 shows in a schematic axonometric view a panel machine according to the present
invention, surrounded by a protection structure;
Figure 2 is analogous to Figure 1, but with the protection structure partially removed;
Figure 3 shows in a magnified scale the detail of a door to close an access opening
of the protection structure of the panel machine of Figure 1;
Figure 4 is a section along a vertical median plane of the panel machine of Figure
1;
Figure 5 shows in detail an element for the centring of a sheet on the work plane,
with the respective mechanism of movement.
[0018] With reference to the drawings, in Figure 1 and 2 a panel machine according to the
present invention is shown. The panel machine comprises a work plane 1 for a sheet
to be machined 5, a bending press 2 provided with a bending die (that will be described
in detail later) positioned frontally to the work plane 1, a mechanical hand 4 mobile
as regards the work plane 1 for the movement of the sheet 5 during machining, and
a protection structure 6, consisting of sheets preferably provided with windows, that
encloses the work plane 1 with the mechanical hand 4, and the bending press 2. In
this example, inside the protection structure 6 two openings 7 for the access to the
machining zone are provided on opposite sides of the work plane, that allow a human
operator to introduce a sheet to be machined 5 on the work plane 1 and to remove the
sheet once the machining is completed. In the example shown, the access openings are
associated with respective doors 8, that can be seen in a magnified scale in Figure
3, hinged to a supporting frame (not shown for clearness reasons) in the protection
structure 6 in such a way so as to result to be turnable around respective horizontal
axes. Preferably, in order to facilitate the opening and closing of the doors 8, conventional
gas cylinders (not shown) can be provided.
[0019] In the example shown, the protection structure 6 comprises two openings for the access
to the work plane, so that the latter turns out to be accessible from either sides;
however, it could also be possible to provide for a single access opening.
[0020] More details about the structure of the bending press 2 and the mechanical hand 4,
and the relative way of operating, are shown in Figures 4 and 5, that will now be
described, in which for clearness reasons the protection structure 6 is not shown.
[0021] In a known way, the mechanical hand 4 comprises a carriage globally indicated by
9, conformed as an "arch press" mobile as regards the work plane 1 through a longitudinal
slit 3 of the same on rectilinear horizontal guides 10 supported by a bed 11 which
rests on the floor, said guides 10 extending perpendicular to the front of the bending
press 2. A fluid mechanical cylinder 50 causes the movement of the carriage 9 along
the guides 10 in the direction toward or away from the bending press 2. The carriage
9 supports a hydraulic vice 12 with overlaid and coaxial lower and upper jaws 13,
14 having flat and horizontal opposite walls suitable to clamp between them the sheet
to be machined, as shown in Figure 4. The lower jaw 13 is fixedly mounted on the upper
end of a horizontal shaft 15 set into rotation by a rotator 16 mounted on the lower
part of the carriage 9 and capable to confer the shaft 15 and the lower jaw 13 angular
shift by 90° and 180° in one and in the opposite direction. The upper jaw 14 is fixedly
mounted to the lower end of a vertical shaft 17 turningly held in idle mode by a bracket
arm 51 held in turn in a slidingly vertical way by the end of the upper part of the
carriage 9. A fluid mechanical cylinder, not shown, causes the lowering and lifting
of the bracket arm 51, and therefore of the jaw 14, in such a way as to respectively
clamp the sheet to be machined 5 between the jaws 13, 14 or to release the same sheet.
The shaft 17 must idle in rotation around its own axis, in order not to prevent the
rotation of the sheet 5 by means of the rotator 16, the jaw 14 having to co-operate
with the jaw 13 in order to clamp the sheet 5.
[0022] In addition, the mechanical hand 4 comprises a thrust means 19, that can also be
seen in Figure 2 and shown in Figure 4 into two different operating positions, globally
mobile with the carriage 9 and also independently set in motion by a respective fluid
mechanical cylinder 52 and sliding in a slide created in the lower part of the carriage
9. When the thrust means 19 is in the position of rest, it is substantially in correspondence
of the throat of the arch press 9; by moving forward along the slide toward the bending
press 2 under the action of the cylinder 52, the thrust means 19 abuts against the
back edge of the sheet to be machined in such a way as to push the sheet 5 and to
allow its automatic correct positioning, as it will be described more in detail later.
[0023] The bending press 2 comprises a bearing structure having a substantially "C" shaped
section and comprising a lower wing 21 and an upper wing 22. The lower wing 21 rests
on the floor, while the upper wing 22 is hinged to the lower wing 21 in correspondence
of flanges 23 located on the back of the latter, in such a way so as to result turnable
around a horizontal axis indicated by A. A cylinder-piston unit 24 produces the rotation
of the upper wing 2 around the axis A, being provided at least one vertical rod 25
(schematically indicated by dots and lines) which acts as a guide to the movement
of the upper wing 22. Frontally to the lower wing 21 a vertical support 26 is fixed
having a free flat and horizontal upper surface located at the same level of the work
plane 1, that forms a lower blank holder. Frontally to the upper wing 22 an upper
blank holder 27 is fixed in such a way so as to extend vertically toward the bottom,
that is provided with a free flat lower surface suitable to co-operate with the upper
surface of the lower blank holder in order to clamp the sheet to be machined near
the edge of the same to be bent.
[0024] In the space comprised between the upper and lower wings 22, 21 a bending blade holder
28 is housed, having a substantially "C" shape, in cross section. The blade holder
28 comprises a lower arm 29 and an upper arm 30 which extend toward the front of the
bending press 2. A lower bending blade 34 is fixed at the end of the lower arm 29,
while an upper bending blade 35 is fixed to the upper arm 30. On the back, the blade
holder 28 is hinged to a torsion bar 31 in such a way so as to result as being turning
around the axis indicated by C. The torsion bar 31 is also turnable around the horizontal
axis indicated by B under the action of a fluid mechanical cylinder, of which only
the rod 32 is schematically shown in dots and lines. A fluid mechanical cylinder (whose
rod 33 is schematically shown in dots and lines) produces the rotation of the blade
holder 28 around the axis C. The combination of the rotation of the torsion bar 31
around its own axis B, which determines the position of the axis of rotation C of
the blade holder 28, and the rotation of the blade holder 28 around the axis C allows
a great variety of movements to the bending blades 34, 35 in order to obtain bends
with various angles both upward and downward.
[0025] Frontally to the support 26 a known reference-bearing block 36 is mounted, that has
a flat horizontal upper surface 37 at the same level of the work plane 1 and inside
of which reference elements 38 visible also in Figures 1 and 2 are located. The block
36 is movable in a direction perpendicular to the front of the bending press 2, so
that it can move away from or toward the same. In addition, the reference elements
38, normally retractable inside the block 36 during the machining of the sheet, can
project in such a way so as to jut out from the surface 37. The reference elements
38 can also move in a direction parallel to the front of the bending press, in such
a way that they can mutually move toward or away from each other.
[0026] As shown in Figure 5, each reference element 38 (shown by a continuous line in a
position of rest, retracted and by dots and lines in the operating position, projecting)
is turningly supported by a respective carriage 61 mounted on an endless screw 39,
extending parallel to the front of the bending press 2 and mortised on a pulley 62-which
in turn is set in rotation by a motor 60 through a belt 63. The carriage 61 can therefore
move in the direction parallel to the front of the bending press. Parallel to the
screw without end 39, a bar 64 extends, which form the axis of rotation of the reference
element 38. A cylinder-piston unit 65, whose vertical rod 66 is hinged to the reference
element 38 while the cylinder is hinged to the reference-bearing block 36 causes the
rotation of the reference 38 around the bar 64, in such a way so as to produce the
projection or the retraction of the reference element 38 from the reference bearing
block 36.
[0027] The operation of the panel machine previously illustrated will be now described.
[0028] Initially, the operator takes a sheet to be machined, opens the door 8 in order to
accede to the work plane 1, and positions the sheet to be machined on the work plane,
in a roughly central position. Therefore, the operator closes the door 8 and he turns
the panel machine on. The mechanical hand 4, initially in a position distant from
the bending press 2 and with the upper jaw 14 lifted, moves toward the bending press.
In the meantime, the thrust means 19 is activated by the relative cylinder 52, and
moves along the relative slide toward the front of the bending press 2, in such a
way so as to abut against the back edge of the sheet to be machined and to push the
latter toward the bending press. Simultaneously, the two retractable reference elements
38 project, so that the fore edge of the sheet, pushed by the thrust means 19, abuts
against the same reference elements. The conformation of the reference elements 38
is such as to allow the centring of the sheet to be machined, in a direction parallel
to the front of the bending press, whether or not this has sheared corners. The possibility
to move the reference elements 38 in a direction parallel to the front of the bending
press allows the centring of sheets having variable dimensions. Therefore, the operator
has not to worry about positioning the sheet on the work plane in a precise manner.
[0029] At this point, the reference elements 38 retract, and the thrust means 19 returns
to its rest position, in such a way as not to represent an obstacle during the following
stages of the machining. The upper jaw 14 lowers and in co-operation with the jaw
13, it holds the sheet in a substantially central position. Therefore, the mechanical
hand moves the sheet forward, toward the bending press. The upper wing 22 of the latter
is lifted, so that the upper blank holder is enough distant from the lower blank holder
26 to allow the passage of the sheet. Once the latter has been introduced in the bending
press, the cylinder 24 produces the lowering of the upper wing 22 so that the upper
blank holder 27 presses against the lower blank holder 26, an edge of the sheet to
be machined projecting inside the bending press. At this point, the cylinders whose
rods are indicated by 32 and 33 in Figure 4 set in motion the blade holder 28, whose
bending blades 34 and 35 cause bending of the edge of the sheet, in co-operation with
the blank holder 26, 27. Once the edge of the sheet has been bent in the desirable
way, the upper wing 22 of the bending sheet is lifted, and the sheet released from
the hold of the upper blank holder 27. The mechanical hand 4 backs, removing the sheet
from the bending press and, if other edges of the sheet have to be bent, it carries
out the rotation of the sheet by 90° or 180° by means of the rotator 16. When the
sheet has been rotated in the desired manner, the mechanical hand moves forward again
bringing the edge of the sheet to be machined inside the bending press, and the operations
described above are repeated.
[0030] At the end of the machining of the sheet, the operator stops the machine, he opens
the door 8, and he removes the sheet from the work plane, he takes a new sheet, he
positions it on the work plane, he closes the door and turns the machine on.
1. Machine for the production of metal sheet panels with bent edges, comprising a work
surface (1) for a sheet to be machined, a bending press (2) provided with a bending
die and located frontally to the work plane, a mechanical hand (4) mobile as regards
the work plane for the displacement of the sheet (5) during machining, sheet positioning
means (19, 38) to automatically position the sheet (5) to be machined after this has
been introduced by the operator on the work plane (1), characterised in that the work plane is substantially enclosed inside a protection structure (6), said
protection structure comprising at least one opening (7) of access to the work plane
for the feeding to and the removal of the sheet from the work surface on behalf of
a human operator, and in that said at least one access opening (7) is associated to respective means (8) for the
interdiction of the access to the work plane during machining, said sheet positioning
means (19, 38) being enclosed in said protection structure (6) and comprising retractable
reference elements (38) normally retracting as regards the upper surface of the work
plane (1) and suitable to project as regards said upper surface of the work plane
during a stage of the positioning of the sheet (5) to engage a front edge of the panel,
and a mobile thrust means (19) that engages a back edge of the sheet to push the front
edge of the sheet against said reference elements.
2. Machine according to claim 1, characterised in that said interdiction means (8) of the access to the work plane (1) comprise a door associated
to said opening (7), openable by the operator for the introduction and the removal
of the sheet (5) before and after machining, and closable to prevent the access to
the work plane during machining.
3. Machine according to claim 2, characterised in that said door (8) is mounted on said protection structure (6) in correspondence of said
opening (7) in such a way as to result to be turnable around a horizontal axis.
4. Machine according to claim 1, characterised in that it comprises a pair of said retractable reference elements (38).
5. Machine according to any one of the previous claims, characterised in that said mechanical hand is mobile in a direction towards/away from said bending press
(2) and it comprises a vice (12) suitable to clamp the sheet (5) to be machined in
position substantially central to the same, and a rotator (16) suitable to rotate
the sheet (5) in said work plane (1).
1. Vorrichtung zur Herstellung von Metallblechteilen mit abgekanteten Rändern, welche
eine Arbeitsfläche (1) für ein zu bearbeitendes Blech, eine Biegepresse (2), welche
mit einem Biegewerkzeug versehen und vorderseitig zu einer Bearbeitungsebene angeordnet
ist, ein mechanisches Griffteil (4), welches bezüglich der Arbeitsebene zur Verschiebung
des Blechs (5) während der Bearbeitung beweglich ist und eine Blechpositioniereinrichtung
(19,38) aufweist, um das zu bearbeitende Blech (5) automatisch zu positionieren, nach
dem es durch eine Bedienungsperson zu der Arbeitsebene (1) gebracht worden ist, dadurch gekennzeichnet, daß die Arbeitsebene im Innern eine Schutzeinrichtung (6) im wesentlichen eingeschlossen
ist, die Schutzeinrichtung wenigstens eine Zugangsöffnung (7) zu der Arbeitsebene
zur Aufgabe und zur Abnahme des Blechs von der Arbeitsfläche anstelle einer menschlichen
Bedienungsperson aufweist, daß wenigstens eine Zugangsöffnung (7) der entsprechenden
Einrichtung (8) zur Unterbindung eines Zugangs zu der Arbeitsebene während der Bearbeitung
zugeordnet ist, und daß die Blechpositioniereinrichtung (19,38) in der Schutzeinrichtung
(6) eingeschlossen ist und zurückziehbare Referenzelemente (38) aufweist, welche im
Grundzustand bezüglich der oberen Fläche der Arbeitsebene (1) zurückgezogen sind und
bezüglich der oberen Fläche der Arbeitsebene währens eines Vorgangs zur Positionierung
des Blechs (5) vrschiebbar sind, um mit einem vorderen Rand des Blechs (5) in Eingriff
zu kommen, und eine bewegliche Andrückeinrichtung (19) aufweist, welche mit einer
hinteren Kante des Blechs zusammenarbeitet, um die vordere Kante des Blechs gegen
die Referenzelemente zu drücken.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß die Unterbindungseinrichtung (8) für den Zugang zu der Arbeitsebene (1) eine Türe
aufweist, die mit der Öffnung (7) verbunden und durch eine Bedienungsperson zur Aufgabe
und zur Abnahme des Blechs (5) vor und nach der Bearbeitung öffenbar ist sowie schließbar
ist, um den Zugang zu der Arbeitsebene während der Bearbeitung zu verhindern.
3. Vorrichtung nach Ansprch 2, dadurch gekennzeichet, daß die Türe (8) an der Schutzeinrichtung
(6) unter Zuordnung zu der Öffnung (7) derart angebracht ist, daß sie um eine horizontale
Achse drehbar ist.
4. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß sie ein Paar von zurückziehbaren Referenzelementen (38) aufweist.
5. Vorrichtung nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, daß das mechanische Griffteil in Richtung auf die Biegepresse (2) zu und von dieser wegbewegbar
ist und ein Spannblech (12) zur Einspannung des zu bearbeitenden Blechs (5) in einer
Position im wesentlichen mittig hierzu und ein Drehteil (16) aufweist, um das Blech
(5) in die Arbeitsebene zu drehen.
1. Machine pour la production de panneaux en tôle métallique à bords rabattus, comprenant
une surface de travail (1) pour une tôle à usiner, une presse de pliage (2) dotée
d'une matrice de pliage et située frontalement par rapport au plan de travail, une
main mécanique (4) mobile par rapport au plan de travail pour déplacer la tôle (5)
pendant l'usinage et un moyen (19, 38) de positionnement de tôle pour positionner
automatiquement la tôle (5) à usiner après qu'elle a été introduite sur le plan de
travail (1) par l'opérateur, caractérisée en ce que le plan de travail est essentiellement enfermé dans une structure de protection (6),
ladite structure de protection comprenant au moins une ouverture d'accès (7) au plan
de travail pour l'amenée de la tôle sur la surface de travail et son enlèvement hors
de celle-ci par un opérateur humain, et en ce que ladite ouverture d'accès (7) au moins prévue est associée à un moyen respectif (8)
qui interdit l'accès au plan de travail pendant l'usinage, ledit moyen (19, 38) de
positionnement de tôle étant enfermé dans ladite structure de protection (6) et comprenant
des éléments rétractables de référence (8) qui se rétractent par rapport à la surface
supérieure du plan de travail (1) et qui peuvent être déployés par rapport à ladite
surface du plan de travail pendant une étape de positionnement de la tôle (5) en vue
d'engager un bord frontal du panneau, et un moyen (19) mobile de poussée qui engage
un bord arrière de la tôle pour repousser le bord avant de la tôle contre lesdits
éléments de référence.
2. Machine selon la revendication 1, caractérisée en ce que ledit moyen (8) d'interdiction d'accès au plan de travail (1) comprend une porte
qui est associée à ladite ouverture (7), qui peut être ouverte par l'opérateur pour
l'introduction et l'enlèvement de la tôle (5) avant et après l'usinage et qui peut
être fermée pour empêcher l'accès au plan de travail pendant l'usinage.
3. Machine selon la revendication 2, caractérisé en ce que ladite porte (8) est montée sur ladite structure de protection (6) en correspondance
à ladite ouverture (7) de manière à pouvoir être tournée autour d'un axe horizontal.
4. Machine selon la revendication 1, caractérisée en ce qu'elle comprend une paire desdits éléments rétractables de référence (38).
5. Machine selon l'une quelconque des revendications précédentes, caractérisée en ce que ladite main mécanique peut être déplacée dans une direction qui s'approche ou qui
s'éloigne de ladite presse de pliage (2) et en ce qu'elle comprend une pince (12) qui convient pour pincer la tôle (5) à usiner dans une
position essentiellement centrale de cette tôle, et un dispositif (16) de mise en
rotation qui convient pour faire tourner la tôle (5) dans ledit plan de travail (1).