Note: Descriptions are shown in the official language in which they were submitted.
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"Improved punching machine for metal sheet panels."
* * * * *
DESCRIPTION
The present invention refers to an improved punching machine for metal
sheet panels.
As known, punching machines for metal sheet panels generally
comprise a work table for a panel to be punched, a "C" shape or an "arched"
annular bearing structure, having a groove where the work table passes
through and to which a punching head is mounted, and moving means
(manipulator) for the panel to be punched on the work table to hold the panel
at one of its sides and to bring it in correspondence of the pllnching head.
Since in general the panel must be punched in points even very distant
from each other, for example along all the sides of the same, the manipulator
must also have an extended stroke in order to be able to bring all those
points of the panel that have to be punched in correspondence of the
punching head. According to the dimension of the panel such stroke can be
so extended to make it necessary to carry out the movement of the panel in
successive stages, getting hold of the panel, moving it by a certain length,
releasing it, bringing the manipulator back to its original position, getting
again hold of the panel and then going on with the movement of the same.
Obviously, this slows machining time considerably.
In view of the state of the art described, object of the present invention
has been to provide a punching machine that would solve the problem
pointed out above.
According to the present invention, such object is attained thanks to a
punching machine for metal sheet panels comprising a work table, a bearing
structure for punching means having a groove where said work table passes
through, and moving means for a panel on said work table to bring the panel
in correspondence of said punching means, characterised in that said
punching means comprise two punching units that are mounted to said
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bearing structure and are substantially facing one another.
The characteristics and the advantages of the present invention will be
rendered more evident by the following detailed description of some
embodiments thereof, illustrated as non-limiting examples in the enclosed
drawings, in which:
Figure 1 shows in axonometry a pl-nching machine according to a first
embodiment of the present invention;
Figure 2, 3 and 4 are plan views of the punching machine of Figure 1,
showing three different operating conditions;
Figure 5 is sectional view along line V-V of Figure 3;
Figure 6 shows, in a sectional view analogous to the one of Fig. 5, a first
variation of the punching machine according to the first embodiment;
Figure 7 shows, in a sectional view analogous to the one of Fig. 5, a
second variation of the pllnching machine according to the first embodiment;
Figure 8 shows a pllnching machine in accordance with a second
embodiment of the present invention, in axonometry;
Figure 9 is a plan view of the punching machine of Figure 8, in a
particular operating condition; and
Figure 10 is section along line X-X of Figure 9.
With reference to the drawings, in Figures 1 to 7 there is shown a
punching machine according to a first embodiment of the present invention.
Such punching machine comprises a work table 1 for the panels to be
machined, and a bearing structure 2 that can have a substantially close
arched annular shape, as in Figures 1 to 6, or that can be made of two
substantially facing "C" shape or "arched" structures 2', 2", as in Figure 7. Inboth cases, the bearing structure 2 has a central groove 3 through which the
work table 1 passes.
Two substantially facing punching heads 4', 4" are mounted to the
bearing structure 2, inside the groove 3. Each punching head comprises two
overlapping parallelepiped blocks 5 and 6, the first known as punch holder
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block, fixed to the upper part of the bearing structure 2 and provided with
one or more punching tools, the second, known as matrix holder block, fixed
instead to the lower part of the bearing structure 2 and below the work table
1 and provided with respective matrix dies for the punching tools. In the
example shown in the drawings, the two punching heads are of the "multi-
press" type, that is, each one provided in the punch holder block 5 with a
plurality of punching tools 7 (small tools), 8 (large tools) having variable
dimensions and operable independently one from another by means of
respective actuator pistons 9, 10 and, in the matrix holder block 6, a
respective plurality of matrix dies 11 (for small tools), 12 (for large tools).
Punching heads of this type, already known and described for example in
U.S. patent No. 4391123, allow to perform a plurality of punching
operations without the need to substitute the punching tools. As an
~l~ern~tive, the punching heads could be of the "mono-press" type, each one
provided with one single actuator piston in the punch holder block, and
either provided or not with systems for the quick change of the punch-matrix
set. This is not essential to the purpose of the present invention.
Still with reference to Figures 1 to 7, the punching machine
comprises two manipulators 13, 14 located in correspondence of the two
ends of the work table 1. Each manipulator 13, 14 comprises a first carriage
15 that is movable along slide guides 16 in a direction indicated by Y in
Figure 1 perpendicular to the bearing structure 2, and a second carriage 17
movable instead along a direction indicated by X in the same Figure,
parallel to the bearing structure 2. Pinchers 18 suitable to hold a metal sheet
panel P in correspondence of an edge of the same are associated to the
carriage 17.
With reference to Figures 2 and 4, a panel to be punched P 1 is fed either
by an operator or automatically on the work table 1, in the direction
indicated by A in Figure 2 (that is indifferently from the right or from the
left) in correspondence with the manipulator 13, while the manipulator 14 is
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engaged in the handling of a previous panel P0 for the machining of the
same on behalf of the punching heads 4', 4". After having carried out the
centring of panel Pl with the aid of the centring means 19 (for example,
pawls projecting and retracting with regards to the work table 1), the
manipulator 13 holds one back edge of the panel Pl with its pincers 18.
Moving to Figure 3, once the machining of the panel P0 is completed, the
carriage 15 ofthe manipulator 14 moves back along the guides 16, thus
clearing the machining zone within the groove of the bearing structure 2, and
it proceeds with the release of the panel P0 by means of the movement of
carriage 17, indifferently in either one of the two directions S indicated in
Figure 3. Simultaneously, the carriage 15 ofthe manipulator 13 moves
forward along the guides 16 in the direction Y, thus bringing the fore edge of
the panel Pl in the machining zone within the groove of the bearing
structure 2. The carriage 17 of the manipulator 13, while moving in the
direction X, moves the panel P 1 into the various positions in such a way that
the punching heads 4', 4" can carry out the m~hining where requested. Once
the machining of the edge or more in general of the fore half of panel P 1 has
been completed, the manipulator 14 moves forward along the guides 16 and
it gets hold ofthe fore edge of panel Pl by its pincers 18; therefore the two
manipulators exchange panel P 1 between themselves. The manipulator 13
releases panel P 1 and moves back along the guides 16, getting back to the
position shown in Figure 2. While the manipulator 14 moves the panel Pl in
the various positions necessary to carry out machining of the edge or, more
in general, of the back half of the same, the manipulator 13 is ready to
receive a new panel, and the cycle is thus repeated.
Owing to the fact that two punching heads, instead of one single
punching head as in the known punching machines, are mounted to the
bearing structure 2, at a distance and substantially facing each other, the
course in the direction X that the carriages 17 of the manipulators must run
is considerably reduced. In particular, it is possible to avoid movements of
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the panel in successive stages, which largely slow the machining, by which
the pincers of a manipulator get hold of the panel, therefore the carriage 17
moves along the direction X, the panel is released, the carriage 17 gets back
to its initial position, gets again hold of the panel and therefore repeats the
movement. For example, with a 1500 mm stroke along the direction X the
punching machine is capable to carry out the machining of sheets having
dimensions of 2500-2600 mm along X, without any need to carry out
movements in successive stages.
The two plmching heads 4', 4" can be fixed to the arch 2. It is also
possible to provide for a plurality of fixing positions for the punching heads
4', 4" in the arch 2, so that during the assembly of the machine it is possible
to vary the mutual distance between heads. As an alternative, as it is
schematically shown in Figure 6, the two heads (or possibly only one of
them) can be mounted in a sliding way along the direction X, by means
sliders 50 and guides 51 and, for example, adjusting screws 52, in order to
be able to adjust the mutual distance as a function of the dimensions of the
panel to be punched.
A variation of the previously described plmching machine is shown in
Figure 7. Here, besides the fact that the bearirlg structure 2 is not a closed
arch but it is formed of two arches 2', 2", it is also possible to observe that
the two arches 2', 2" can be preferably made become mobile with regards to
a base 100 of the punching machine, in order to be able to adjust the mutual
distance between the two punching heads 4', 4".
In Figures from 8 to 10 there is shown a punching machine according to
a second embodiment of the present invention. Unlike the previous
embodiment, the punching machine comprises a single manipulator 13, and
it is provided with a rotator 60 for the panel to be machined. The sole
manipulator 13, without the rotator 60, would in fact not allow to carry out
m~hining in correspondence of the edge of the panel that is engaged with
the pinchers 18. The rotator 60 instead allows to rotate the panel once all the
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punching operations on the free edge of the panel have been completed, and
therefore to be able to carry out the punching also on the other edge of the
panel. In Figure 9 the operation of rotation of the panel P on behalf of the
rotator 60 is sho~vn.
