U.S. patent application number 11/180732 was filed with the patent office on 2006-01-19 for die cushion apparatus of press machine.
Invention is credited to Kiyokazu Baba, Seiji Seki.
Application Number | 20060010954 11/180732 |
Document ID | / |
Family ID | 35598006 |
Filed Date | 2006-01-19 |
United States Patent
Application |
20060010954 |
Kind Code |
A1 |
Baba; Kiyokazu ; et
al. |
January 19, 2006 |
Die cushion apparatus of press machine
Abstract
A die cushion apparatus of a press machine which makes possible
to manufacture a plurality of types of products of different sizes
by one press machine and capable of minimizing a production
facility, and which comprises a plurality of die cushion units,
each having a cushion pad and a rise and fall drive unit for
vertically driving the cushion pad, that are aligned in a direction
perpendicular to a work conveying direction, and a control unit
capable of individually and independently controlling the plurality
of die cushion units.
Inventors: |
Baba; Kiyokazu; (Ishikawa,
JP) ; Seki; Seiji; (Ishikawa, JP) |
Correspondence
Address: |
POSZ LAW GROUP, PLC
12040 SOUTH LAKES DR.
SUITE 101
RESTON
VA
20191
US
|
Family ID: |
35598006 |
Appl. No.: |
11/180732 |
Filed: |
July 14, 2005 |
Current U.S.
Class: |
72/351 |
Current CPC
Class: |
B21D 24/02 20130101 |
Class at
Publication: |
072/351 |
International
Class: |
B21D 22/21 20060101
B21D022/21 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 16, 2004 |
JP |
2004-209599 |
Apr 15, 2005 |
JP |
2005-118514 |
Claims
1. A die cushion apparatus of a press machine comprising; a
plurality of die cushion units each having a cushion pad and an
elevating drive unit that vertically moves the cushion pad, aligned
in a bed in a direction perpendicular to a work conveying
direction.
2. The die cushion apparatus of the press machine according to
claim 1, further comprising a control unit capable of individually
and independently controlling the plurality of die cushion
units.
3. The die cushion apparatus of the press machine according to
claim 2, wherein the control unit controls the plurality of die
cushion units in synchronism with each other that are operated for
a work common to each other.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a die cushion apparatus of
a press machine, and more particularly to a die cushion apparatus
suitable for a press machine of a production facility for
manufacturing various types of products of different sizes.
[0003] 2. Description of the Related Art
[0004] A press machine A for executing drawing work, as shown in
FIG. 16, includes a lower die (punch) E mounted on a bed B and an
upper die (die) U mounted to a slide S, and includes a blank holder
H operated to rise or fall through a cushion rod R by a die cushion
apparatus C installed in the bed B.
[0005] The die cushion apparatus C includes a cushion pad Cp
provided to be vertically movable in the bed B, and an oil pressure
servo cylinder Cs for rising and lowering the cushion pad Cp. The
die cushion apparatus C, when drawing a work W by lowering the
slide S, operates to prevent a "crack", a "wrinkle", etc. from
occurring in the product by pressing the work W to the upper die U
at a predetermined pressure through the blank holder H.
[0006] Also, the die cushion apparatus C is controlled to
sequentially operate a preliminary acceleration stroke a, a drawing
stroke b, an auxiliary lift c, locking d, etc., as shown by a solid
line (die cushion motion) with a motion (broken line) of the slide
S (upper die U) as shown in FIG. 17 based on position information
of the blank holder H and pressure information to the work W.
[0007] Incidentally, the die cushion apparatus of the press machine
is not only used as a means for driving the blank holder, but also
it is used, without saying, as a buffer device and a lifting device
of the product with various type pressing, such as "drawing",
"bending", "cutting", etc.
[0008] Meantime, a body of an automobile is noted as a typical
product manufactured by frequently using a pressing work, however,
since types of panels that form one automobile are various, there
has been a problem that the production facility becomes uselessly
large in scale.
[0009] More particularly, the panels forming one automobile are
largely classified, as shown in FIGS. 18A to 18C, into three types
of a class A panel (a large size product) Pa, such as a roof panel,
a floor pan, etc., a class B panel (an intermediate size product)
Pb, such as a door panel, a hood panel, etc, and a class C panel (a
small size product) Pc, such as various types of pillars, a cross
member, etc. The class A panel Pa is manufactured in a press
working line (tandem press line) PLa in which a plurality of
specialized press machines Aa are aligned in parallel through a
work loader T, the class B panel Pb is manufactured in a press
working line (tandem press line) PLb in which a plurality of
specialized press machines Ab are aligned in parallel through the
work loader T, and further the class C panel Pc is manufactured in
a press working line (tandem press line) PLc in which a plurality
of specialized press machines Ac are aligned in parallel through
the work loader T.
[0010] Thus, in the conventional production facility, since the
class A panel Pa, the class B panel Pb and the class C panel Pc are
respectively manufactured by the specialized press machine As,
press machine Ab and press machine Ac, a plurality of press working
lines are required to manufacture all the panels forming one
automobile, an inconvenience of introducing a large scale of the
production facility has not been avoided.
[0011] In view of the above-mentioned fact, an object of the
present invention is to provide a die cushion apparatus of a press
machine which can manufacture a plurality of types of products
having different sizes by one press machine and which can also
achieve minimization of the production facility.
SUMMARY OF THE INVENTION
[0012] A first aspect of the present invention provides a die
cushion apparatus of a press machine, comprising a plurality of die
cushion units each having a cushion pad and an elevating drive unit
for vertically moving the cushion pad, aligned in a bed in a
direction perpendicular to a work conveying direction.
[0013] According to the die cushion apparatus of the first aspect
of the invention, the plurality of die cushion units are provided
in parallel along a direction perpendicular to the work conveying
direction, a plurality of types of products can be manufactured by
one press machine.
[0014] Further, according to the die cushion apparatus of the first
aspect of the invention, since the plurality of types of products
having different sizes are manufactured by one press machine, a
production facility for manufacturing a large variety of types of
products can be minimized as much as possible.
[0015] A second aspect of the present invention provides the die
cushion apparatus according to the first aspect of the invention,
which further comprises a control unit capable of individually and
independently controlling the plurality of die cushion units.
[0016] According to the die cushion apparatus of the press machine
of the second aspect of the invention, since the die cushion
apparatus comprises the control unit for individually and
independently controlling the plurality of die cushion units, it is
possible to operate individual die cushion units for separate works
or to operate only a specific die cushion unit.
[0017] A third aspect of the present invention provides the die
cushion apparatus of a press machine according to the second aspect
of the invention, wherein the control unit controls a plurality of
die cushion units in synchronism with each other that are operated
for a work common to each other.
[0018] According to the die cushion apparatus of a press machine of
the third aspect of the invention, since a plurality of die cushion
units, which operate on a common work, can be controlled in
synchronism with each other, it is possible to make a work of a
size extending over the plurality of die cushion units.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a sectional front view schematically showing an
embodiment of a die cushion apparatus of a press machine according
to the present invention;
[0020] FIG. 2 is a plan view of an essential portion showing an
embodiment of the die cushion apparatus according to the present
invention;
[0021] FIG. 3 is a sectional view taken along a line III-III in
FIG. 2 showing one embodiment of the die cushion apparatus
according to the present invention;
[0022] FIG. 4 is a structural view of a control system in the die
cushion apparatus shown in FIG. 1;
[0023] FIG. 5A, FIG. 5B and FIG. 5C are schematic plan views
respectively showing operation modes of the die cushion apparatus
according to types of products;
[0024] FIG. 6 is a conceptual view showing a structure of the die
cushion apparatus when a small size product is manufactured;
[0025] FIG. 7 is an appearance perspective view showing a structure
of a general mold;
[0026] FIG. 8 is a conceptual view showing a structure of the die
cushion apparatus when an intermediate size product is
manufactured;
[0027] FIG. 9 is a conceptual view showing a structure of the die
cushion apparatus when a large size product is manufactured;
[0028] FIG. 10A and FIG. 10B are conceptual plan views showing
operation modes of the die cushion apparatus according to types of
products;
[0029] FIG. 11A and FIG. 11B are conceptual plan views showing
operation modes of the die cushion apparatus according to types of
products;
[0030] FIG. 12 is a schematic view showing another embodiment of a
die cushion unit in the die cushion apparatus of the present
invention;
[0031] FIG. 13 is a schematic view showing another embodiment of a
die cushion unit in the die cushion apparatus of the present
invention;
[0032] FIG. 14 is a schematic view showing another embodiment of a
die cushion unit in the die cushion apparatus of the present
invention;
[0033] FIG. 15 is a schematic view showing another embodiment of a
die cushion unit in the die cushion apparatus of the present
invention;
[0034] FIG. 16 is an entire conceptual view showing a conventional
press machine;
[0035] FIG. 17 is an operation diagram showing the state of a
motion in the die cushion apparatus; and
[0036] FIG. 18A, FIG. 18B and FIG. 18C are conceptual plan views
showing a press working line built by using a conventional press
machine.
DETAILED DESCRIPTION OF THE INVENTION
[0037] Embodiments of the present invention will be described in
detail based on the accompanied drawings.
[0038] FIG. 1 to FIG. 4 show an example of the die cushion
apparatus of the present invention which is applied to a press
machine for processing a work (metal plate) into a panel of a
desired shape in a production facility of, for example, an
automobile. Incidentally, since the entire structure of the press
machine is not fundamentally different from the conventional press
machine A shown in FIG. 16, a detailed description concerning the
entire structure of the press machine will be omitted.
[0039] As shown in FIG. 1 to FIG. 3, a first unit (die cushion
unit) 11, a second unit (die cushion unit) 12, a third unit (die
cushion unit) 13 and a fourth unit (die cushion unit) 14 that
constitute a die cushion apparatus 10 are provided in a base (bed)
2 of a press machine 1 installed on a floor.
[0040] The first unit 11 includes a cushion pad 11P having a
rectangular shape viewed from above (plane view), and a pair of oil
pressure servo cylinders 11S, 11S which are raising and lowering
drive means for vertically moving the cushion pad 11P.
[0041] The cushion pad 11P is contained in one of four sections
obtained by partitioning a peripheral wall 2A of the base 2 by
partition walls 2B, and installed to be vertically movable with
respect to the base 2 by slidably contacting a base guide g with a
pad liner 1.
[0042] Furthermore, the pair of oil pressure servo cylinders 11S,
11S are fixed to a beam 2C installed in the base 2, and
synchronously operated like one oil pressure servo cylinder, by
connecting mutual oil paths by pipes 11p.
[0043] Needless to say, the oil pressure servo cylinder 11S has a
structure which can suitably change a pressure of a blank holder (a
wrinkle suppressing pressure), a stroke, a locking position, etc.,
similarly to the oil pressure servo cylinder in a conventional die
cushion apparatus.
[0044] The second unit 12 also includes a cushion pad 12P having a
rectangular shape viewed from above (plane view), and a pair of oil
pressure servo cylinders 12S, 12S, similarly to the first unit 11.
The cushion pad 12P is installed and contained vertically movably
in one section of the base 2, and the pair of oil pressure servo
cylinders 12S, 12S are constructed to operate like one oil pressure
servo cylinder.
[0045] Also, the third unit 13 includes a cushion pad 13P having a
rectangular shape viewed from above (plane view), and a pair of oil
pressure servo cylinders 13S, 13S, similarly to the first unit 11,
and the cushion pad 13P is installed and contained vertically
movably in one section of the base 2, and the pair of oil pressure
servo cylinders 13S, 13S are operated like one oil pressure servo
cylinder.
[0046] Furthermore, the fourth unit 14 also includes a cushion pad
14P having a rectangular shape viewed from above (plane view), and
a pair of oil pressure servo cylinders 14S, 14S, similarly to the
first unit 11. The cushion pad 14P is installed and contained
vertically movably in one section of the base 2, and the pair of
oil pressure servo cylinders 14S, 14S are operated like one oil
pressure servo cylinder.
[0047] Here, the first unit 11, the second unit 12, the third unit
13 and the fourth unit 14 are provided to be aligned in a direction
perpendicular to a work conveying direction (a direction
perpendicular to the surface of paper in FIG. 1). Thus, the cushion
pads 11P, 12P, 13P and 14P in the units 11 to 14 are arranged as if
one large die cushion pad was divided into four in the direction
perpendicular to the work conveying direction.
[0048] More particularly, the first unit 11, the second unit 12,
the third unit 13 and the fourth unit 14 are laid out in a
positional state for use simultaneously in one step of pressing,
and further, laid out so that a work and a product are conveyed
simultaneously by a work conveying unit such as a vacuum cup, etc.
extended in the direction perpendicular to the work conveying
direction.
[0049] On the other hand, the die cushion apparatus 10 has an
operation controller 20 for controlling to operate the first unit
11, the second unit 12, the third unit 13 and the fourth unit 14
independently from each other or synchronously with each other, to
be described later.
[0050] The operation controller 20 has a first controller 21 for
independently controlling the first unit 11, and this first
controller 21 controls to operate the first unit 11 in a
predetermined die cushion motion (refer to FIG. 17) based on
position information and pressure information, similarly to the
conventional die cushion apparatus.
[0051] Furthermore, the operation controller 20 has a second
controller 22 for independently controlling the second unit 12, a
third controller 23 for independently controlling the third unit
13, and a fourth controller 24 for independently controlling the
forth unit 14. These second controller 22 to the fourth controller
24 control to operate the second unit 12 to the fourth unit 14 in a
predetermined die cushion motion (refer to FIG. 17) based on
position information and pressure information, similarly to the
first controller 21.
[0052] The operation controller 20 has a supervising controller 25
together with the first controller 21 to the fourth controller 24.
This supervising controller 25 outputs a command signal to the
first controller 21 to the fourth controller 24 to be described
later based on a working state inputted from an operation panel 26,
etc. of the press machine 1 to thereby supervise the independent
operation control of the first unit 11, the second unit 12, the
third unit 13 and the fourth unit 14 and also control to operate
synchronously with each other in an arbitrary combination of the
first unit 11 to the fourth unit 14.
[0053] Incidentally, in the press machine 1, a class A panel, such
as a roof panel, etc., of a large size product, a class B panel,
such as a door panel, etc. of an intermediate size product, and a
class C panel, such as a cross member, etc. of a small size product
can be used as an object to be worked. As shown in FIG. 5A, when an
object to be worked is the class A panel Pa, all the first unit 11
to the fourth unit 14 are used for manufacturing a common one class
A panel Pa.
[0054] Also, as shown in FIG. 5B, when an object to be worked is
the class B panel Pb, the first unit 11 and the second unit 12,
which are adjacent to each other, and the third unit 13 and the
fourth unit 14, which are adjacent to each other, are used for
manufacturing a common one class B panel Pb, respectively, and
totally two class B panels Pb, Pb are manufactured.
[0055] Furthermore, as shown in FIG. 5C, an object to be worked is
the class C panel Pc, all the first unit 11 to the fourth unit 14
are used for manufacturing the class C panels Pc, respectively, and
totally four class C panels Pc, Pc, Pc, Pc are manufactured.
[0056] Here, FIG. 1 and FIG. 4 show an embodiment when the class C
panel (small size product) Pc like FIG. 5C is an object to be
worked, and in the base 2 of the press machine 1, a lower die L1, a
lower die L2, a lower die L3 and a lower die L4 are installed
respectively in an upper area of the first unit 11, the second unit
12, the third unit 13 and the fourth unit 14.
[0057] A blank holder H1, a blank holder H2, a blank holder H3 and
a blank holder H4 are installed in the upper area of the first unit
11, the second unit 12, the third unit 13 and the fourth unit 14
through a cushion pin CP1, a cushion pin CP2, a cushion pin CP3 and
a cushion pin CP4.
[0058] On the other hand, in the slide of the press machine 1, an
upper die U1, an upper die U2, an upper die U3 and an upper die U4
are mounted at positions opposed to the lower die L1, the lower die
L2, the lower die L3 and the lower die L4 through holders 5,
respectively.
[0059] In the following description, in the press machine 1 of the
above-mentioned structure, one scope of controlling to operate to
the first unit 11 to the fourth unit 14 when the class A panel Pa,
the class B panel Pb, and the class C panel Pc shown in FIG. 5A,
FIG. 5B and FIG. 5C are manufactured will be described with
reference to FIG. 1 and FIG. 4 showing the entire structure of the
die cushion apparatus 10.
[0060] In the press machine 1 of the above-mentioned structure,
when the four class C panel Pc (refer to FIG. 5C) of the same shape
are manufactured at the same time, as shown in FIG. 6, the lower
dies L1 to L4, and blank holders H1 to H4 are installed in the
upper area of the first unit 11 to the fourth unit 14 in the bed 2,
the upper dies U1 to U4 corresponding to the lower dies L1 to L4
are installed in the slide 4, and works Wc of the class C panel Pc
is supplied to the individual dies.
[0061] An operation controller 20 of the die cushion apparatus 10
controls to operate the first unit 11 to the fourth unit 14 in a
predetermined die cushion motion (refer to FIG. 17) corresponding
to the specification of the class C panel Pc independently from
each other by the first controller 21 to the fourth controller 24
based on the working state ("four class C panels are manufactured",
"specification of class C panel", etc.) inputted from a control
panel 26.
[0062] Incidentally, as shown in FIG. 7, square-rod shape heel
guides La and heel guides Ua are projected from four corners of the
lower die L1 and the upper die U1. The blank holder H1 is
vertically moved with respect to the lower die L1 while the blank
holder H1 is guided by the heel guide Ua by slidably contacting
guide recesses Ha at four comers of the blank holder H1 with the
heel guide Ua.
[0063] The oil pressure servo cylinders 11S, 11S of the first unit
11 for vertically moving the blank holder H1 are installed in
parallel along the work conveying direction as shown in FIG. 3, but
are connected via pipings 11p, 11p as described above, to operate
like one oil pressure servo cylinder. Incidentally, a structure may
be provided so that one oil pressure servo cylinder is
provided.
[0064] On the other hand, in the press machine 1 of the
above-mentioned structure, when the two class B panels Pb (refer to
FIG. 5B) are manufactured simultaneously, as shown in FIG. 8, the
lower die L11 and the lower die L12, and the blank holder H11 and
the blank holder H12 are installed in the upper area of the first
unit 11 and the second unit 12 and in the upper area of the third
unit 13 and the fourth unit 14, and the upper die U11 and the upper
die 12 corresponding to the lower die L11 and the lower die 12 are
installed in the slide 4, and works Wb of the class B panel Pb are
supplied to the individual dies.
[0065] The operation controller 20 of the die cushion apparatus 10
controls to operate the first unit 11, the second unit 12, the
third unit 13 and the fourth unit 14 in a predetermined die cushion
motion (refer to FIG. 17) corresponding to the specification of the
class B panel Pb based on the working states ("two class B panels
are manufactured", "a common work for the first unit 11 and the
second unit 12 is an object to be worked", "a common work for the
third unit 13 and the fourth unit 14 is an object to be worked",
and "specification of class B panel", etc.) inputted from the
control panel 26.
[0066] Here, in the operation controller 20, the first unit 11 and
the second unit 12 provided to manufacture the one class B panel Pb
are controlled to be operated synchronously with each other, and
the third unit 13 and the fourth unit 14 provided to manufacture
the other class B panel Pb are controlled to be operated
synchronously with each other.
[0067] More particularly, the first unit 11 and the second unit 12
are controlled to be operated synchronously with each other in such
a manner that the first unit 11 is controlled to be operated based
on a command signal from the first controller 21 and the second
unit 12 is controlled to be operated based on a feedback signal
with the operation of the first unit 11, by a so-called
master/slave type controlling method.
[0068] Similarly, the third unit 13 and the fourth unit 14 are
controlled to be operated synchronously with each other in such a
manner that the third unit 13 is controlled to be operated based on
a command signal from the third controller 23 and the fourth unit
14 is controlled to be operated based on a feedback signal with the
operation of the third unit 13, by a so-called master/slave type
controlling method.
[0069] In this manner, the first unit 11 and the second unit 12,
and the third unit 13 and the fourth unit 14 are controlled to be
operated synchronously with each other, and the blank holder H11
and the blank holder H12 vertically move without inclining in a
direction perpendicular to the work conveying direction, and hence
a damage of a die unit due to an inclination of the blank holder is
prevented.
[0070] Incidentally, whether any of the first unit 11 and the
second unit 12 with the common work Wb as an object to be worked is
used as a master of the operation control or whether any of the
third unit 13 and the fourth unit 14 with the common work Wb as an
object to be worked is used as a master of the operation control
can be, of course, suitably set in view of various conditions.
[0071] On the other hand, in the press machine 1 of the
above-mentioned structure, when one class A panel Pa (refer to FIG.
5A) is manufactured, as shown in FIG. 9, one lower die L20 and one
blank holder H20 are installed in the upper area of the first unit
11 to the fourth unit 14 in the bed 2, and the upper die U20
corresponding to the lower die L20 is installed in the slide 4, and
the work Wa of the class A panel Pa is supplied.
[0072] The operation controller 20 of the die cushion apparatus 10
controls to operate the first unit 11, the second unit 12, the
third unit 13 and the fourth unit 14 in a predetermined die cushion
motion (refer to FIG. 17) corresponding to the specification of the
class A panel Pa based on the working states ("one class A panel is
manufactured", "a common work in the first unit 11 to the fourth
unit 14 is an object to be worked", "specification of the class A
panel", etc.) inputted from the control panel 26.
[0073] Here, in the operation controller 20, the first unit 11, the
second unit 12, the third unit 13 and the fourth unit 14 are
controlled to be operated synchronously with each other.
[0074] More particularly, the first unit 11 is controlled to be
operated based on the command signal from the first controller 21,
and the second unit 12, the third unit 13 and the fourth unit 14
are controlled to be operated based on the feedback signal with the
operation of this first unit 11, synchronously with each other by a
so-called master-slave type controlling method.
[0075] Thus, the first unit 11, the second unit 12, the third unit
13 and the fourth unit 14 are controlled to be operated
synchronously with each other, and the blank holder H20 is thereby
vertically moved without any inclination in a direction
perpendicular to the work conveying direction, and hence a damage
of the die unit due to the inclination of the blank holder is
prevented.
[0076] Incidentally, any of the first unit 11 to the fourth unit 14
with a common work Wa as an object to be worked can be suitably set
as a master for operation control in view of various
conditions.
[0077] Thus, according to the press machine 1 adopting the die
cushion apparatus 10 concerning the present invention, by using a
different work as an object to be worked for each of the individual
die cushion units of the first unit 11 to the fourth unit 14, or by
using a common work as an object to be worked for the combination
of die cushion units, products of a plurality of types having
different sizes can be manufactured by one press machine 1.
[0078] Further, according to the die cushion apparatus 10 of the
above-mentioned structure, since products of a plurality of types
having different sizes can be manufactured by one press machine 1,
a production facility for manufacturing a wide variety of types of
products can be minimized as much as possible.
[0079] Incidentally, as shown in FIG. 10A, when four class C panels
Pc1, Pc2, Pc3, and Pc4 having largely different shapes
(specification) are manufactured, the lower dies L1 to L4, the
blank holders H1 to H4, and the upper dies U1 to U4, which are
respectively for the class C panels Pc1 to Pc4, are used, and works
Wc, Wc, Wc, and Wc of the class C panels Pc1 to Pc4 are supplied to
the individual dies.
[0080] The operation controller 20 of the die cushion apparatus 10
is controlled to be operated in a predetermined die cushion motion
(refer to FIG. 17) corresponding to the specification of the class
C panel Pc independent from each other by the first controller 21
to the fourth controller 24 based on the working state inputted
from the control panel 26.
[0081] More particularly, the first unit 11 to the fourth unit 14
are controlled to be operated independently along with pressure of
a blank holder, stroke, operating timing, etc. corresponding to the
specifications of the class C panels Pc1 to Pc4.
[0082] Particularly, rising speeds of the first unit 11 to the
fourth unit 14 are controlled so that the timings of the respective
blank holders H1 to H4 reaching a predetermined lift rising end
responding to a shape of a product become the same irrespective of
a difference of the stroke due to a depth of drawing, etc. by
considering a removal of the product by a work conveying unit, such
as a vacuum cup, etc.
[0083] Thus, in the press machine 1 adopting the die cushion
apparatus 10 according to the present invention, a plurality of the
products having the same types (class B panel, class C panel) and
largely different shapes (specifications) can be manufactured
simultaneously in the same step.
[0084] On the other hand, as shown in FIG. 10B, when two class C
panels Pc, Pc and one class B panel Pb are manufactured, as shown
in FIG. 6, the lower dies L1, L2, the blank holders H1, H2, and the
upper dies U1, U2 are installed, as shown in FIG. 8, the lower dies
L12, the blank holder H12, and the upper die U12 are installed,
works Wc, Wc of the class C panel Pc are supplied between the lower
dies L1, L112 and the upper dies U1, U2, and the work Wb of the
class B panel Pb is supplied between the lower die L12 and the
upper die U12.
[0085] The operation controller 20 of the die cushion apparatus 10
controls to operate the first unit 11 and the second unit 12 by the
first controller 21 and the second controller 22 in a predetermined
die cushion (refer to FIG. 17) corresponding to the specification
of the class C panel Pc independently from each other based on the
working state inputted from the control panel 26, and controls to
operate the third unit 13 and the fourth unit 14 used to
manufacture the class B panel Pb in a predetermined die cushion
motion (refer to FIG. 17) corresponding to the specification of the
class B panel Pb synchronously with each other.
[0086] Also, the operation controller 20 controls the rising speeds
of the first unit 11 to the fourth unit 14 so that the respective
blank holders H1 to H4 become the same timings to reach a
predetermined lift rising end responding to the shape of the
product irrespective of the difference of the stroke due to the
depth of the drawing, etc. by considering the removal of the
product by the work conveying unit, such as a vacuum cup, etc.
[0087] Thus, in the press machine 1 adopting the die cushion
apparatus 10 according to the present invention, a plurality of
types of the products (class B panel, class C panel) having
different sizes can be manufactured simultaneously in the same
step.
[0088] Also, as shown in FIG. 11A, when one class B panel Pb is
manufactured, as shown in FIG. 8, the lower die L11, the blank
holder H11, and the upper side U11 are installed, and the work Wb
of the class B panel is supplied between the lower die L11 and the
upper die U11.
[0089] The operation controller 20 of the die cushion apparatus 10
controls to operate the second unit and the third unit used to
manufacture the class B panel Pb based on the working state
inputted from the control panel in a predetermined die cushion
motion (refer to FIG. 17) corresponding to the specification of the
class B panel Pb synchronously with each other.
[0090] Further, as shown in FIG. 11B, when the two class C panels
Pc, Pc are manufactured, as shown in FIG. 6, the lower dies L2, L3,
the blank holders H2, H3, and the upper dies U2, U3 are installed,
and the work Wc of the class C panel Pc is supplied between the
lower dies L2, L3 and the upper dies U2, U3.
[0091] The operation controller 20 of the die cushion apparatus 10
controls to operate the second unit and the third unit used to
manufacture the class C panel Pc by the second controller 22 and
the third controller 23 based on the working state inputted from
the control panel in a predetermined die cushion motion (refer to
FIG. 17) corresponding to the specification of the class C panel Pc
independently from each other.
[0092] Thus, in the press machine 1 adopting the die cushion
apparatus 10 according to the present invention, the specific die
cushion may not be used. Further, which die cushion is selected can
be set freely. It is needless to say that a die cushion should be
selected so that an eccentric load generated at the working time
may become as small as possible.
[0093] Here, in the above-mentioned embodiment, a plurality of die
cushion units in which common works to each other are used as
objects to be worked are controlled to be operated synchronously
with each other by a master/slave type controlling method. However,
as a structure for embodying the master/slave type controlling
method, existing various structures may be suitably adopted.
[0094] Also, as a method for controlling to operate a plurality of
die cushion units synchronously with each other, not only the
master/slave type controlling method exemplified in the embodiment,
but also existing various type controlling method may be, of
course, effectively applied.
[0095] Further, in the above-mentioned embodiment, a rise and fall
drive unit of the die cushion unit in the die cushion apparatus is
exemplified in the example constructed by the oil pressure servo
cylinder. However, for example, the rise and fall drive unit of the
die cushion unit can be constructed by a suitable drive means, such
as, for example, a motor-driven servo motor, etc.
[0096] FIG. 12 is a schematic view showing another embodiment of
the die cushion unit. In this die cushion unit 100, a cushion pad
101 is interconnected to a motor-driven servo motor 107 through a
ball screw 102, a coupling member 103, a large pulley 104, a belt
105 and a small pulley 106 and a rise and fall drive unit 110 is
configured by these ball screw 102, the coupling member 103, the
large pulley 104, the belt 105, the small pulley 106, and the
motor-driven servo motor 107.
[0097] Incidentally, pad liners 1, 1, . . . which are slidably
contacted with a base guide provided at a base (bed) of the press
machine, not shown, are provided on each side face of the cushion
pad 101.
[0098] A nut portion 102a of the ball screw 102 is fixedly provided
to a lower portion of the cushion pad 101, a threaded portion 102b
of the ball screw 102 is engaged with the nut portion 102a, and the
lower part of the threaded portion 102b is connected to the
coupling member 103. Further, the coupling member 103 is supported
by a bearing, etc., to the beam 108 in the base, and the large
pulley 104 is provided at the lower part of the coupling member
103. The small pulley 106 is provided at a rotary shaft of the
motor-driven servo motor 107, and a belt 105 is wound on the large
pulley 104 and the small pulley 106.
[0099] When the rotary shaft of the motor-driven servo motor 107 is
rotated, the small pulley 106, the large pulley 104, the coupling
member 103 and the threaded portion 102b are operated to be
rotated. When the threaded portion 102b is rotated, the threaded
portion 102a is linearly moved in a vertical direction, that is, in
a rising or falling direction along the threaded portion 102b, and
thereby the cushion pad 101 is raised or lowered together with the
nut portion 102a.
[0100] In the above-mentioned die cushion unit 100, the operation
(rotation of the rotary shaft) of the motor-driven servo motor 107
constituting the rise and fall drive unit 110 is current
controlled, and thereby the operation (pressure of a blank holder,
stroke, locking position, etc.) of the cushion pad 101 can be
suitably controlled, similarly to the oil pressure servo cylinder
in the conventional die cushion unit.
[0101] FIG. 13 is a schematic view showing another embodiment of
the die cushion unit. In a die cushion unit 200, a cushion pad 201
is interlocked to a motor-driven servo motor 207 through a ball
screw 202, a coupling member 203, a large pulley 204, a belt 205
and a small pulley 206, and a rise and fall drive unit 210 is
configured by these ball screw 202, the coupling member 203, the
large pulley 204, the belt 205, the small pulley 206 and the
motor-driven servo motor 207.
[0102] Incidentally, pad liners 1, 1, . . . slidably contacted with
a base guide provided in a base (bed) of the press machine, not
shown, are provided on each side face of the cushion pad 201.
[0103] A threaded portion 202b of the ball screw 202 is fixed to a
lower part of the cushion pad 201, a nut portion 202a of the ball
screw 202 is engaged with this threaded portion 202b, and the
coupling member 203 is connected to the lower part of the nut
portion 202a. Further, the coupling member 203 is supported by a
bearing, etc., to the beam 208 in the base, a large pulley 204 is
provided in the lower part of the coupling member 203, a small
pulley 206 is provided on a rotary shaft of the motor-driven servo
motor 207, and the belt 205 is wound on the large pulley 204 and
the small pulley 206.
[0104] When the rotary shaft of the motor-driven servo motor 207 is
rotated, the small pulley 206, the large pulley 204, the coupling
member 203, and the nut portion 202a are operated to be rotated.
When the nut portion 202a is operated to be rotated, the threaded
portion 202b is linearly moved in a vertical direction, that is,
the rising and falling direction along the nut portion 202a, and
thereby the cushion pad 201 is operated to be raised or lowered
together with the threaded portion 202b.
[0105] Even in the above-mentioned die cushion unit 200, an
operation of the motor-driven servo motor 207 constituting the rise
and fall drive unit 210 is current-controlled to be rotated, an
operation (pressure of a blank holder, locking position, etc.) of
the cushion pad 201 can be controlled suitably, similarly to the
oil pressure servo cylinder in a conventional die cushion
apparatus.
[0106] FIG. 14 is a schematic view showing another embodiment of
the die cushion unit. In this die cushion unit 300, a cushion pad
301 is coupled to a rotary shaft of a motor-driven servo motor 307
through a plunger rod 311 and a piston 312 and further through a
ball screw 302, a coupling member 303, a large pulley 304, a belt
305, and a small pulley 306, and a rise and fall drive unit 310 is
constructed by these plunger rod 311, the piston 312, the ball
screw 302, the coupling member 303, the large pulley 304, the belt
305, the small pulley 306 and the motor-driven servo motor 307.
[0107] A columnar plunger rod 311 is fixed to the lower portion of
the cushion pad 301, and this plunger rod 311 is slidably supported
by a cylindrical plunger guide 313 fixed to a beam 308 in the base.
The plunger rod 311 is operated to be raised or lowered while being
supported, and the plunger guide 313 guides the plunger rod 311 and
the cushion pad 301 coupled to the plunger rod 311 in the rising or
falling direction.
[0108] A cylinder 311a having an opening in a downward direction is
formed at a lower part of the plunger rod 311, a piston 312 is
slidably contained in the cylinder 311a, an oil pressure chamber
314 is formed by the inner wall surface of the cylinder 311a and
the upper surface of the piston 312, and pressure oil is filed in
this oil pressure chamber 314.
[0109] The oil pressure chamber 314 has its axial center which is
the same as those of the plunger rod 311 and the ball screw 302,
and further a pressure oil port of the oil pressure chamber 314 is
connected to an oil pressure circuit, not shown, and the pressure
oil communicates between the oil pressure chamber 314 and the oil
pressure circuit. The pressure oil in the oil pressure chamber 314
alleviates an impact generated when the upper die is contacted with
the work, and when an oil pressure becomes a predetermined value or
more, the pressure oil is exhausted to a tank (not shown) to
perform an overload protective function.
[0110] A lower end of the piston 312 is contacted with an upper end
of the threaded portion 302a in the ball screw 302. A spherical
recess surface 312a is formed on the lower end of the piston 312,
and a spherical surface protrusion surface 302c is formed on an
upper end of the threaded portion 302b opposed the recess surface
312a. Incidentally, a protruding surface may be formed on the lower
end of the piston 312, and a recess surface may be formed on the
upper end of the threaded portion 302b.
[0111] Here, a bar-like member like the threaded portion 302b is
strong against an axial force operating at an end part, but weak to
a bending moment. When the upper end of the threaded portion 302b
is a spherical shape, even if the cushion pad 301 is inclined so
that a bending moment is generated at the upper end of the threaded
portion 302b, only the axial force is operated at the threaded
portion 302b entirety, and a damage of the threaded portion 302b
due to the eccentric load can be prevented.
[0112] The nut portion 302a is engaged with the threaded portion
302b of the ball screw 302, and the lower portion of the nut
portion 302b is connected to the coupling member 303. Further, the
coupling member 303 is supported to the beam 308 in the base by
bearing, etc., and the large pulley 304 is provided at a lower
portion of the coupling member 303. The small pulley 306 is
provided at a rotary shaft of the motor-driven servo motor 307, and
the belt 305 is wound on the large pulley 304 and the small pulley
306.
[0113] When the rotary shaft of the motor-driven servo motor 307 is
rotated, the small pulley 306, the large pulley 304, the coupling
member 303 and the nut portion 302a are operated to be rotated.
When the nut portion 302a is rotated, the threaded portion 302b is
linearly moved in a vertical direction, that is, a raising or
lowering direction along the nut portion 302a, and the cushion pad
301 is operated to be raised or lowered together with the threaded
portion 302b, the piston 312, the plunger rod 311.
[0114] In the above-mentioned die cushion unit 300, the operation
of the motor-driven servo motor 307 constituting the rise or fall
drive unit 310 is current-controlled, and the operation (pressure
of a blank holder, stroke, locking position, etc.) of the cushion
pad 301 can be suitably controlled, similarly to the oil pressure
servo cylinder in the conventional die cushion apparatus.
[0115] FIG. 15 is a schematic view showing another embodiment of
the die cushion unit. In this die cushion unit 400, a cushion pad
401 is coupled to a rotary shaft of a motor-driven servo motor 407
through a plunger rod 411 and a piston 412 and further through a
ball screw 402, a coupling member 403, a coupling 421 and a
reduction gear 422, and a rise and fall drive unit 410 is
constructed by these plunger rod 411, the piston 412, the ball
screw 402, the coupling member 403, the coupling 421, the reduction
gear 422 and the motor-driven servo motor 407.
[0116] The motor-driven servo motor 407 is installed on a lower
region of the coupling member 403, and the reduction gear 422 is
connected to the rotary shaft of the motor-driven servo motor 407.
Incidentally, the motor-driven servo motor 407 may include a
reduction gear.
[0117] An output shaft of the reduction gear 422 is connected to
the lower portion of the coupling member 403 through the coupling
421, and the ball screw 402, the coupling member 403, the coupling
421, and the output shaft of the reduction gear 422 are coaxially
disposed. Further, according to a structure of the reduction gear
422, a rotary shaft of the motor-driven servo motor 407 is also
disposed coaxially with the ball screw 402, etc.
[0118] Here, the die cushion unit 400 is fundamentally the same in
the structure as the die cushion unit 300 described above except a
layout of the motor-driven servo motor 407 to the coupling member
403, and a transmission mechanism of a power from the motor-driven
servo motor 407 to the coupling member 403, and, therefore, in the
constituting elements of the die cushion unit 400, having the same
operation as the die cushion unit 300 are attached by numerals of
400 order adding 100 to the same numerals in FIG. 14, and a
detailed description will be omitted.
[0119] In the die cushion unit 400, when the rotary shaft of the
motor-driven servo motor 407 is rotated, a gear, etc. in the
reduction gear 422 are rotated, the output shaft of the reduction
gear 422, the coupling 421, the coupling member 403, and the nut
portion 402a are operated to be rotated. When the nut portion 402a
is rotated, the threaded portion 402b is linearly moved in a
vertical direction, that is, in a raising and lowering direction
along the nut portion 302a, and thereby the cushion pad 401 is
operated to be raised or lowered together with the threaded portion
402b, the piston 412, and the plunger rod 411.
[0120] Even in the above-mentioned die cushion unit 400, the
operation of the motor-driven servo motor 407 constituting a rise
and fall drive unit 410 (the rotation of the rotary shaft) is
current-controlled, and the operation of the cushion pad 401
(pressure of a blank holder, stroke, locking position, etc.) of the
cushion pad 401 can be suitably controlled, similarly to the oil
pressure servo cylinder in the conventional die cushion
apparatus.
[0121] Incidentally, in the above-mentioned embodiments, the
example in which the present invention is applied to the press
machine for building a production facility of an automobile has
been described. However, the die cushion apparatus according to the
present invention can be effectively applied not only to the
production facility of the automobile, but also the press machine
for building the production facility of various products.
* * * * *