Note: Descriptions are shown in the official language in which they were submitted.
Description
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The invention relates to a machine tool, in
particular for the manufacturing, from sheet metal~
of mechanical parts such as pulleys~ wheels and
similar.
The object of the present invention is to provide a
machine which~ working on the blank~ constituted of
sheet metal~ can perform a plurality of different
plastic deformation operations ~deep-drawing~ roll-
folming~ etc~ and shaving operations
(turnlng~ boring~ etc~) without having to move or
re-position the piece,
Qdded to this advantage of permitting the performing
of several different kinds of operation~ through
plastic deformation or through shaving without
having to move or reposition the piece~ i5 the
versatility of the present machine~ capable of
performl~ng thus a large range of different
operations.
: The abovenamed advantages are gained by a machine
~: tool, in particular for the manufac~uring 4rom sheet
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metal of mechanical parts such as pulleys~ wheels
and similar~ as it is described in the claims which
follow.
F~\lther characteristics and advantages of the
C~5 present invention will appear in the detailed
description which followsy which is of a preferred
but not exclLIsive embodiment of the invention5
represented in the accompanying illustrations by way
of e~ample and not in a uniqLle embodiment:
- figs. la and lb show, from the same schematic
frontal view5 pa~tially sectiorled according to plane
II II (~s represented in fig~2)~ respectively the
~pper and lower parts of the machine tool;
- fig 2 shows a schematic section made according to
plane I-I of figs la and lb;
- fig~ ~ shows, in enlarged scal e~ the detail which
is indicated by a circle in figs la and lb;
- figs 4a5 4b~ 4c5 4d5 4e5 4f5 495 4h show some of
the stages in the operations performed by the
7~ invention~
With reference to the drawings5 fig. 1 denotes the
sturdy frame ~1) comprising a hori~ontal deck (~),
below and mounted to which is a support (~)~ to
which in turn is rotatably mounted a chuckhea~ quill
~4) with vertlcle axis. ~ pulley ~S) is fitted to
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the quill (4)~ being a component of the mechanical
chain-drive transmission via which same quiIl is
rotated by a motor (6). Internally to the quill (4)
is mounted a toolhead spindle (7) e~:hioiting at its
05 top end a threaded mount for the attachment of a
tool or toolhead. 8aid spindle (7) is rotatably
housed insi~e a sleeve (8)~ which is in its turn
free to slide axially inside the quill (4) ht its
bottom end the spindle (7) is secured to the tubular
stem (q) of a coaxial annular se~tion hydraulic
cylinder (10)~ and is thus slidably oonstrained. The
cylinder (10) is mounted to the boY~ (11)~ which is
solidly mounted to the deck (2)~ and has the purpose
of producing the a~sial movements of the spindle (7) 5
lS which is rotatably housed at its bottom end inside
basrel (12)~ in its turn able to slide freely in an
axial direction with respect to the body (1~) The
bott=m end of the spindle ~7) eY~hibits a projection
(14) of appropriate axial length5 which~ together
with a corresponding sliding seat ~i5) shaped into
the body (1~) constitutes an aY~ially-sliding pair.
On th;e deck (~), which stands on the floor on sturdy
posts (I6)5 the bases of three guide columns (17)
are mounted~ parallel to the axis of the coaxial
25 ~ qLlii~l (41~and spindle (7~: =n these guide columns
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517) is mounted a strong support element (18), which
is slidably mobile in an axial direction~ ~t their
top ends~ the guide columns ~17), which are disposed
as in the corners of an equilateral triangle~ with
05 the quill (4) at their centre, are permanently
c~nnected by means of a strong joining element tl9
To the support element ~18) is rotatably mounted a
chuckhead quill t2C~) internally to which, in exactly
the same way as for spindle ~7~ housed internally to
quill (4)~ a second toolhead spindle (21) i9 housed~
Like spindle ~7)~ spindle (~1 ) i 5 ~1 50 rot~t~ly
mounted inside a coaxial barrel~ which in turn is
free to slide in an a~tial direction within the quill
~20)~ The support element (i8) is secured to the
bottom end of the tubular stem (22) of a powerful
hydraullc jack (23), which is disposed coaxially
with respect to shafts (2~) and (21) and is
perfectly allgned with the axis of shafts (4) and
(7). The jack ~2~) is of annular section and its
~ body is solidly fixed to the element (i9). ~t Its
top end the spindle (21) is fixedly connected to the
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tubular stem of a coaxial hydraulic cylinder (24)~
whose body is fixed}y solid to the hydraulic jack
(23~ with tubular elements (25) interposed~ ~
movab~le sliding pair (26) is positioned between the
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element (25) and the part o~ the spindle ~21) haused
inside it to permit the same spindle S21) to slide
freely only in an axial direction with respect to
the quill ~20)~ The bottom ends of quills ~4) and
~5 ~20)~ positioned so that they are exactly facing one
anotherg are each capable o~ holding chucks,
~rranged on.the deck (2) at angularly equidistant
positions with respect to the guide columns ~17)~
are three mobile cross-sliding tool rests ~27~ which
are slidably mounted on fixed slides ~28)~ in three
radial directions with respect to the common axis of
quills t4) and (20) and spindles ~7) and (21)~ Each
tool rest ~27) i5 moved slidably along its slide
(2~) by action of a hydraulic cylinder ~29)~ Each
tool rest is fitted with a toolhead or turret t30)
rotatably mounted on a pivot whose axis is parallel
to those of quills (4) and ~20) and spindles ~7~ and
~21)~ The rotation of the turret ~30) around the
pivot ~31) is commanded via a small hydraulic
cylinder ~32). Each turret can bear several tools~
In thls embodiment rotating tools ~34) for roll-
formi:ng or cutting~ and fixed tools for turning ~33)
are used.
~ hollaw chuck ~35) is mounted to the top end of the
quill ~4). ~ similar hollow chuck ~36) is mounted to
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the bottom end of the second quill (20). The blank,
fl~t or in a previously deep-drawn hollow axial-
symmetric shape~ is clamped between the two chucks
and held in position between them by means of the
05 considerable force exerted by the hydraulic cylinder
(?~)~ With the blank held tight in this way, the
selected tools on the toolheads ot turrets (30),
which are positioned on the tool rests ~27)~ can
perform their tasks~ as may the tools or t~olhea~s
which can be mounted respectively on the tDp end of
the spindle (7) and the bottom end of the spindle
(21), if this is required.
The~machine~ equipped with the appropriate tools~
may`be used in the performing of a wide selection of
~ task:s, and in particular in the manufact-lring of
; mechanical parts ~or motor transmission~ ~y way of
e.~ample, in figs~ 4a~ 4b, 4c, 4d, 4e~ 4f, 49, 4h~
~some of t.he most significant phases of a work cycle
~are represented~ in which a sheave for chain-driven
O transmission;is manufactured out of a flat metal
sheet af constant thlckness t37). ~t the top end of
the quill t4)~ a hollow chuck (35~ is mounted~ which
is equipped with a self-centring three-jaw device
(~8) for the external gripping of the blank. Said
self-centr~ing device (~8) is operated by means of
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the a~ial movements of a centring piece (3q)
attached to the end of the toolhead spindle (7)~
which interacts directly with the jaws of the self-
centring device (38)~ Said self-centring device has
~5 at its top end a punch (40). ~t the bottom end of
quill (~0) a hollow chuc~ (36) is mounted~ around
which a coaxial annular mobile element t41) is
externally and coaxially positioned: this element i5
pushed in a downward direction by the pressure of a
spring (42)~ By action of the roll-forming tools
(44) mounted on the toolhead or turret (30) of ane
of the sliding toolrests (27)~ the blank (4~)
(previously coaxially deep-drawn on the chuck (~6))
can undergo a series of plastic deformations aimed
~5 at producing a corrugation (45~ in the part of the
blank where successively small V grooves (48) will
be formed. Next~ using another roll-forming tool
(46), the corrugations (45) are crushed in a radial
direction so that a cylindrical area is obtained
where the thickness of the blank is notably
increased with regard to previously~ as shown in
fig. 4c ~y means of still another roll-forming taol
(47)~ the iV grooves (48) are formed~ while~
commanded by the hydraulic eylinder (lO), the
~5 spindle ~7) thrusts the punch ~40) upwaros,
completing the formation of the intern~l part of the
blank:~ which will constitute the hub of the pulley.
The formation of the small V" graoves ~eing thus
completed~ the self-centring jaw device (~) is
activate~ at the s~me time as the punch ~40~ i5
lowe~ed~ Then the chuck: (36) is raised by action of
the jack ~2~) so that the rolling tools (49~ and
(S~) can make~ one after the other~ their two
g~-ooves ~50) for v-belts~ ~t completion of the
rolling operations~ a cutting-off tool (51) mounted
on a toolrest (27~ and a cutter-reamer (52) mounted
on a toolhead fi:ced on the bottom end of the
toolhe~ spindle ~Zl)~ are brought into use. When
these operations are completed~ the rot~tion of the
quill ~4) IS stopped and the finished piece can now
be removed from the se}f-centring jaw device ~8) by
~aising the spindle (7) ~nd thus opening the jaws.
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