U.S. patent application number 11/834336 was filed with the patent office on 2008-02-07 for servo-driven cupping press.
This patent application is currently assigned to Advanced Engineered Systems, Inc.. Invention is credited to James E. Ribordy.
Application Number | 20080028817 11/834336 |
Document ID | / |
Family ID | 39027817 |
Filed Date | 2008-02-07 |
United States Patent
Application |
20080028817 |
Kind Code |
A1 |
Ribordy; James E. |
February 7, 2008 |
SERVO-DRIVEN CUPPING PRESS
Abstract
A cupping press includes at least one blanking die that operates
between a rest position and a forming position through the action
of a first servomotor. At least one forming punch operates between
a retracted position and an extended position. The forming punch in
the extended position is at least partially disposed in a forming
cavity defined in a lower die of the press. The operation of the
cupping press is controlled by a control circuit that is
electrically connected to the first servomotor. The control circuit
operates to generate a synchronization pulse based on a parameter,
and functions to coordinate the operation of the first servomotor
with the synchronization pulse.
Inventors: |
Ribordy; James E.; (South
Beloit, IL) |
Correspondence
Address: |
LEYDIG VOIT & MAYER, LTD
TWO PRUDENTIAL PLAZA, SUITE 4900, 180 NORTH STETSON AVENUE
CHICAGO
IL
60601-6731
US
|
Assignee: |
Advanced Engineered Systems,
Inc.
South Beloit
IL
|
Family ID: |
39027817 |
Appl. No.: |
11/834336 |
Filed: |
August 6, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60836171 |
Aug 7, 2006 |
|
|
|
Current U.S.
Class: |
72/347 |
Current CPC
Class: |
B21D 22/30 20130101 |
Class at
Publication: |
72/347 |
International
Class: |
B21D 22/00 20060101
B21D022/00 |
Claims
1. A cupping press, the cupping press comprising in combination: at
least one blanking die, the blanking die operable between a rest
position and a forming position; at least one forming punch, the
forming punch operable between a retracted position and an extended
position, the forming punch in the extended position being at least
partially disposed in a forming cavity defined in a lower die; a
first selvomotor operatively associated with the blanking die, the
first servomotor operating to move the blanking die between the
rest position and the forming position; and a control circuit for
controlling an operation of the cupping press, the control circuit
electrically connected to the first selvomotor, the control circuit
operating to generate a synchronization pulse based on a parameter,
wherein the control circuit operates to coordinate the operation of
the first servomotor with the synchronization pulse.
2. The cupping press of claim 1, further comprising a second
servomotor operatively connected to the forming punch, the second
servomotor operating to move the forming punch between the
retracted position and the extended position.
3. The cupping press of claim 2, wherein the control circuit
further operates to coordinate the operation of the second
servomotor with the synchronization pulse, such that the second
servomotor operates in coordination with the first servomotor.
4. The cupping press of claim 2, wherein the operative connection
between the second servomotor and the forming punch comprises a
cupping cam and at least one roller.
5. The cupping press of claim 2, wherein the first servomotor
operates in two directions, and wherein the second servomotor
operates in one direction.
6. The cupping press of claim 1, further comprising: a plurality of
blanking-punches disposed on the blanking die; and a plurality of
forming punches; wherein each forming punch is associated with a
respective one of the plurality of blanking-punches.
7. The cupping press of claim 6, wherein each of the plurality of
forming punches is configured to move in unison.
8. The cupping press of claim 6, wherein each of the plurality of
forming punches is operatively connected to a respective servomotor
from a plurality of servomotors.
9. The cupping press of claim 1, further comprising a first
position sensor that is configured to send information about a
position of the at least one blanking die to the control circuit,
and a second position sensor that is configured to send information
about a position of the at least one forming punch to the control
circuit.
10. The cupping press of claim 1, wherein the parameter in the
control circuit is a digital signal from a position sensor, the
position sensor disposed in operable relationship with the first
servomotor.
11. The cupping press of claim 1, further comprising a cupping cam
rotatably disposed around a drive shaft, the drive shaft
operatively connected to a second servomotor, wherein a cam
follower that is operatively connected to the forming punch
contacts a curved race of the cupping cam, the curved race having
at least one convex portion, such that the forming punch moves when
the cupping cam rotates.
12. A method of operating a cupping press, comprising the steps of:
acquiring a position signal in a controller, the position signal
relating to the operation of the cupping press; analyzing the
position signal in the controller to generate a synchronization
pulse; comparing the synchronization pulse to an operational
position of a first portion of the press; determining whether the
first portion of the press is coordinated with the synchronization
signal; when the first portion of the press is not coordinated with
the synchronization signal, adjusting a command to at least one
component that operates the first portion of the press.
13. The method of claim 12, further comprising the steps of:
comparing the synchronization pulse to an operational position of a
second portion of the press; determining whether the second portion
of the press is coordinated with the synchronization signal; when
the second portion of the press not coordinated with the
synchronization signal, adjusting a command to at least one
component that operates the second portion of the press.
14. The method of claim 12, wherein the at least one component that
operates the first portion of the press is a first servomotor.
15. The method of claim 12, the method of claim 14, wherein
adjusting a command to the first servomotor comprises adjusting a
command signal that operates to at least one of accelerate,
decelerate, and instantaneously retard the operation of the first
servomotor.
16. The method of claim 12, wherein the position signal acquired in
the controller is a position signal relating to an operational
state of a second portion of the press, the second portion of the
press operated by a second servomotor.
17. An electrically driven dual action cupping press, comprising: a
blanking portion including a blanking-punch operable between a rest
position and a forming position; a first servomotor operable to
move the blanking-punch between the rest position and the forming
position, the first servomotor connected to an output shaft having
at least one threaded section, the first servomotor operating to
selectively rotate the output shaft in a first direction and in a
second direction; a first jaw having a threaded portion and a sled
portion, the threaded portion threadably engaged with the threaded
portion of the output shaft, the sled portion slideably disposed on
an inclined plane formed on a block, the block slideably connected
to the first jaw such that the block is reciprocally movable when
the first jaw is moving; a cupping portion including at least one
punch, the at least one punch connected to a distal end of a
carriage, the carriage slideably disposed within a punch housing,
the carriage operable between a retracted position and an extended
position within the punch housing; a second servomotor operable to
move the carriage and the at least one punch between the retracted
position and the extended position, the second servomotor collected
to a mechanism that operates to rotate a camshaft; a cupping cam
having a curved race, the cupping cam connected to the camshaft,
the curved race in contact with at least one roller, the at least
one roller rotatably connected to the carriage, such that the
carriage is reciprocally moveable within the punch housing when the
camshaft is rotating.
18. The cupping press of claim 17, wherein the blanking-punch is
adapted to cut a workpiece from a sheet of material when the
blanking-punch moves from the rest position to the forming
position, the sheet of material disposed between the blanking punch
and a lower die, and wherein the at least one punch is adapted to
form the workpiece into a cup when the punch moves from the
retracted position to the extended position, the forming
accomplished by pushing the workpiece through a forming ring and
wrapping the workpiece around a distal end of the punch, the
forming ring disposed in the lower die.
19. The cupping press of claim 17, further comprising an electronic
controller operably connected to each of the first servomotor and
the second servomotor, the electronic controller operable to
coordinate an operation of the first servomotor with an operation
of the second servomotor.
20. The cupping press of claim 17, further comprising at least one
position sensor operably associated with the cupping press, wherein
the at least position sensor is disposed to sense a position of at
least one component of the press, the at least one component
comprising an output shaft of the first servomotor, the
blanking-punch, an output shaft of the second servomotor, and the
at least one punch.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the benefit of U.S.
Provisional Patent Application No. 60/836,171, filed Aug. 7, 2006,
which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to machines for
forming metal, and, more particularly, to cupping presses.
BACKGROUND OF THE INVENTION
[0003] Cupping presses are devices known for manufacturing
cup-shaped components from a sheet of material, typically a sheet
of metal or a composite. A cupping operation typically performs
several steps or sequential operations to a sheet of material. A
typical cupping operation begins with punching a round blank of
material from a sheet. Sequential pressing operations that use
punches and forming dies progressively shape the round blank
incrementally into the desired shape.
[0004] To make cans, sheet metal (usually from a roll) is
lubricated and then fed into the cupping press. The cupping press
cuts circular blanks from the sheet steel. A metal forming die in
the cupping press then presses each blank to form a shallow "cup."
The cups are next sent to a "body maker" or transfer press that
elongates them while forcing them into the correct diameter. The
can bodies are then trimmed to a uniform height. After more steps
such as cleaning, coating, printing, and further shaping, the cups
become the bodies of, for example, cans for beverages, dry cell
batteries, and so forth.
[0005] To produce cups efficiently, a cupping press must be both
fast and accurate. Traditionally, attempts to achieve these two
conflicting goals have led to compromises or to unwanted expense
and complexities in the press. Products made by cupping operations
can typically include items made in relatively large volumes, for
example, steel cans for beverages, which also require a high degree
of dimensional accuracy. Moreover, it is desired to combine more
than one operation into a single press.
BRIEF SUMMARY OF THE INVENTION
[0006] The invention provides a cupping press that includes at
least one die and at least one punch. The press operates to cut
blanks from a sheet, and then forms the blanks into cups as the
forming punch extends at least partially into a forming cavity of
the die. A first servomotor that is operatively associated with the
die operates to move the die between the blanking position and the
forming position. A control circuit that is electrically connected
to the first servomotor controls the operation of the cupping
press. The control circuit operates to synchronize the operation of
the first selvomotor with a synchronization pulse.
[0007] In one embodiment, the control circuit or controller of the
cupping press acquires or receives a position signal, and analyzes
the position signal to generate a synchronization pulse. The
controller then compares the synchronization pulse with an
operational position of a first portion of the press to determine
whether the first portion of the press is coordinated with the
synchronization pulse. When the first portion of the press is
determined to be uncoordinated with the synchronization pulse, the
controller adjusts a command signal sent to the first servomotor to
restore the coordination of the first portion with the
synchronization pulse.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0008] FIG. 1 is an outline view in partial cross-section of a
cupping press in accordance with the disclosure.
[0009] FIG. 2 is an outline view of a partial cross-section, from a
different perspective, of a cupping press in accordance with the
disclosure.
[0010] FIG. 3A is an enlarged view in partial cross section of
components surrounding a die of a cupping press.
[0011] FIG. 3B is an enlarged view in partial cross section of
components surrounding the cupping cam.
[0012] FIG. 4 is a block diagram of a cupping press having two
portions in accordance with the disclosure.
[0013] FIG. 5 is a flowchart for a method of operating a cupping
press having at least one servomotor in accordance with the
description.
[0014] FIG. 6 is a functional diagram of a control method for
operating a cupping press.
DETAILED DESCRIPTION
[0015] This disclosure provides a dual action cupping press that is
capable of receiving a sheet of material and performing at least
two operations in sequence; a blanking operation to cut a round
blank out of the sheet, and a first cupping operation to form the
round blank into a shallow cup. The cupping press comprises two
portions that are capable of operating independently, but that are
synchronized during operation to yield desired results. The
synchronization can occur by use of an electronic controller that
is capable of monitoring the operation of each portion of the
press, and command two or more servomotors that operate each of the
two portions such that operation of the two or more motors is
coordinated.
[0016] An outline view of a cupping press 100 is shown in FIG. 1.
The cupping press 100 includes a blanking portion 102 and a
punching portion 104. In the embodiment shown, the blanking portion
102 is disposed on a lower portion of the press 100 and operates to
lower a blanking die 106 into a slot 108. During operation of the
press 100, a sheet feeder (not shown) operates to feed a sheet of
stock material, typically from a roll (not shown), into the slot
108 of the press 100. While the stock material is in the slot 108,
the blanking die 106 operates to punch one or more round blanks of
material from the sheet.
[0017] The blanking portion 102 of the press 100 includes a table
110 that supports the blanking die 106. Motion of the blanking die
106 is accomplished by operation of a first servomotor 112. The
first servomotor 112 is operatively connected to the blanking die
106 and configured to move vertically following the motion of the
blanking die 106. A drive shaft 114 of the first servomotor 112 is
connected to an output shaft 116 through a bushing 118. The bushing
118 is optional, and in some instances may be used to accommodate
any misalignment between the output shaft 116 and the drive shaft
114 during operation of the press 100.
[0018] The output shaft 116 has two threaded sections 120 formed
thereon. The threaded sections 120 of the output shaft or screw
gear 116 are threadably engaged with two jaws 122. Each of the jaws
122 has internal threads (not shown) that mesh with each of the
threaded sections 120. In this embodiment, each jaw 122 is
constrained to move reciprocally within a frame 124 of the press
100 in the horizontal direction, but is free to slide within the
frame 124 such that when the output shaft 116 rotates in one
direction, the jaws 122 can move toward each other. Conversely,
when the output shaft 116 rotates in an opposite direction, the
jaws 122 can move away from each other. An inclined block 126 is
slideably supported within the frame 124 by each of the jaws 122.
The block 126 has two inclined surfaces 130 formed thereon that act
as "skids" to allow each of the jaws 122 to slide thereon. In the
embodiment shown, the inclined surfaces 130 form 20-degree angles
with respect to a horizontal plane, but other angles may be
used.
[0019] A plurality of extension arms 125 rigidly connect the
inclined block 126 with the blanking die 106 such that a vertical
displacement of the inclined block 126 is transmitted to the
blanking die 106. The blanking die 106 is advantageously capable of
constrained motion that follows the motion of the inclined block
126 in the vertical direction. When the first servomotor 112 acts
to lower the blanking die 106, the output shaft 116 rotates to move
the jaws 122 toward each other. As the jaws 122 move toward each
other, they slide on the inclined surfaces 130 moving up the
incline of the block 126 and operating to pull the inclined block
126, and thus the extension arms 125 and the blanking die 106,
downward. Similarly, the process is reversed when the servomotor
112 acts to raise the blanking die 106 by rotating in an opposite
direction. In such instances, the jaws 122 move away from each
other and down the incline of the inclined block 126. In this
fashion, the jaws 122 operate to pull the blanking die 106 upward.
A set of rollers 132 that are operably connected to the table
facilitate motion of the inclined block 126 and other components
moving therewith.
[0020] The press 100 is advantageously a dual-action press in that
it operates to cut blanks out a sheet of material and to perform an
initial punching operation that forms the blanks into shallow cups.
The blanking portion 102 of the press operates to cut the blanks,
and the punching portion 104 accomplishes the initial cup-forming
operation. The punching portion 104 includes a punch guide 134. The
punch guide 134 is located over the blanking die 106 and is
configured to move, following the vertical motion of the blanking
die 106. At times when the blanking die 106 operates to cut one or
more blanks out of the sheet stock, the weight of the punch guide
134 above, and of the inclined block 126 below, act to aid the
downward motion of the blanking die 106. Each one of a plurality of
blanking-punches (not shown) that are disposed on the lower face of
the blanking die 106 advantageously cuts a round blank out of the
sheet of material. The cutting operation is accomplished when each
blanking punch moves downward relative to a lower die 137.
[0021] The punch guide 134 has a plurality of openings 138 formed
therein that accommodate a plurality of punches 140 that pass
therethrough. The punches 140 are connected to a punch frame 142
that allows the punches 140 to move in unison when the punch frame
142 moves vertically between a retracted position and an extended
position. The punch frame 142 is connected to a carriage 144 that
is slideably disposed within a top frame 146 of the punching
portion 104. Two posts 148 that are connected to a lower frame 150
of the press 100 rigidly support the top frame 146. The carriage
144 is free to move vertically, and is constrained to vertical
motion by two extensions 152 that are slideably engaged to the
posts 148. In the embodiment shown, a resilient element, for
example a spring 154, is mounted around each post 148 and
positioned between the extensions 152 and the table 110 such that
the carriage is biased away from the table 110 when the carriage
144 moves toward the table 110.
[0022] The carriage 144 has a set of rollers 156 that are rotatably
connected to the carriage 144 and that engage a peripheral race 158
of a cupping cam 160. The cupping cam 160 is rigidly connected to a
rotating shaft 162 that freely passes through a top portion of the
carriage 144. A bushing 164 ensures that the rotating shaft 162 is
free to rotate with respect to the carriage 144. As the rotating
shaft 162 rotates, the cupping cam 160 rotates with respect to the
rollers 156. The rollers 156 operate to push the carriage 144
downward toward the extended position when the rollers 156 are in
contact with a convex portion 166 of the race 158, and similarly
allow the carriage 144 to move upward toward the retracted position
when the rollers 156 are in contact with the race 158 between the
convex portions 166 thereof. Retraction of the carriage 144 is at
least partially accomplished by an upward spring force of the
springs 154 that are mounted on the posts 148. In an alternate
embodiment, the rotating shaft 162 may have external threads (not
shown) along an outer periphery thereof that engage threaded
portions or collars (not shown) connected to the carriage 144. In
this alternative embodiment, the carriage 144 may move when the
rotating shaft 162 rotates and the threads of the shaft engage the
threaded collars of the carriage 144.
[0023] The rotating shaft 162 is operatively connected to a second
servomotor 168. The second selvomotor 168 is connected to the top
frame 146 of the press 100 and drives a pinion 170. The pinion 170
is configured to transfer motion to a shaft 172 through a flywheel
174. The flywheel 174 shown in this embodiment advantageously
provides rotational inertia for the smooth operation of the shaft
172, as well as a gear reduction between the pinion 170 and the
shaft 172. In the embodiment shown, the shaft 172 has a worm gear
176 connected thereto that operatively causes rotation of the
rotating shaft 162 when the second servomotor 168 is operating.
Because of the axially symmetrical shape of the cupping cam 160,
the second servomotor 168 need only operate in a single direction
to cause a reciprocating motion of the carriage 144, and thus, a
reciprocating motion of the punches 140. As can be appreciated, in
the alternate embodiment discussed above having a roller screw
configuration between the shaft and carriage, the second servomotor
may rotate in two directions to cause a reciprocal motion of the
carriage.
[0024] An electrical box 178 may be connected to a portion of the
press 100, or otherwise appropriately associated therewith. The
electrical box 178 is electrically connected to the first
servomotor 112 through a first line 180, and to the second
selvomotor 168 through a second line 182. The first and second
lines 180 and 182, illustrated in FIG. 1 in dotted lines, can
include one or more electrical conductors that are advantageously
adapted to carry electrical power and signals to control the
operation of each of the first and second servomotors 112 and 168,
as well as carry information relative to the operation and position
of each motor back to a control circuit (not shown) located in the
electrical box 178. Information about the operation of each motor
or operation of the press 100 in general, may include information
from one or more position sensors operating to sense a position of
the blanking die 106, the punches 140, the first servomotor 112,
the second servomotor 168, or any other suitable component.
[0025] A side view of the cupping press 100 is shown in FIG. 2, an
enlarged view of the area surrounding the slot 108 is shown in
partial cross section in FIG. 3A, and an enlarged outline view of
the cupping cap 160 is shown in FIG. 3B. During operation of the
press 100, the blanking die 106 is lowered from a rest position to
a cutting position, and travels a downward or blanking-stroke
distance. During this travel, the blanking die 106 operates to cut
one or more blanks of sheet stock with one or more blanking-punches
302 that are connected to a lower surface of the blanking die 106.
Each blanking punch 302 cooperates with a respective blanking-die
ring 303, disposed in the lower die 137, to cut a round workpiece
of sheet stock. After the workpiece is cut, each blanking-punch 302
continues to move downward and pushes the workpiece against one or
more resilient rings 304. Each resilient ring 304 cooperates with
each respective blanking-punch 302 to clamp and retain the
workpiece in preparation for the forming operation that will
follow.
[0026] Operation of the press 100 does not require a separate
cushioning device that will act to slow the motion of the
blanking-punches 302, because motion of the blanking-punches 302
can advantageously be controlled by the first servomotor 112 with
an incremental accuracy of about one thousandth of an inch (0.0254
mm). Hence, the blanking-punches 302 may be slowed during motion
and achieve an optimal position for retaining the cut blanks
against the resilient rings 304.
[0027] In a subsequent operation, the punch frame 142 is lowered
from a retracted position to an extended position, traveling a
downward or punching-stroke distance, as shown. During this
operation, the blanking punches 302 can advantageously apply a
variable clamp force while retaining the workpiece against the
resilient rings 304. This variable force facilitates forming of the
workpiece into a cup and avoids or reduces the formation of
wrinkles in the cup as it is being formed.
[0028] As described above, the punches 140 move reciprocally when
the cam 160 rotates. The cupping cam 160 has a central portion 184
that forms an opening 186. The rotating shaft 162 passes through
the opening 186 and is rigidly connected to the cupping cam 160 by
a plurality of fasteners (not shown). The fasteners can be
connected to a flange (not shown) of the rotating shaft 162 and
threadably engage a plurality of fastener openings 188 that are
formed in the central portion 184 of the cupping cam 160.
[0029] The peripheral race 158 of the cupping cam 160 includes two
convex and two concave portions that alternately contact the
rollers 156. Transition regions between adjacent portions of the
race 158 can have smooth transitions such that the rollers 156
contacting the race 158 can move smoothly. Each of the concave and
convex portions of the peripheral race 158 can advantageously have
a cycloid shape. In the embodiment shown, each convex portion of
the peripheral race 158 spans over about a 160-degree segment of
the cupping cam 160 and can cause a reciprocal displacement of the
wheels 156 that has an amplitude of about 23/4 in. (7 .mu.m). In
this configuration, each full rotation of the cam 160 will produce
two reciprocal motions of the wheels 156, and thus, two reciprocal
motions of the punches 140. Each punch 140 may advantageously
operate at a rate of eighty-eight complete strokes per minute, or a
rate that is about 10% faster than other known cupping presses.
[0030] Operation of the second servomotor 168 in a continuous
fashion is advantageous, especially at times when another portion
of the press is operating, or while sheet material is fed into the
slot 108. Mechanical wear of the components of the press is reduced
when the press operates continuously as compared to situations
where the servomotors are continuously caused to intermittently
start and stop. For this reason, two flat dwell-portions can be
formed in the peripheral race 158 such that no vertical
displacement of the punches 140 occurs while the wheels 156 are
traversing the dwell-portions. In the embodiment shown, two
dwell-portions are formed in the peripheral race 158, each
dwell-portion spanning a 20-degree segment of the cam 160. The two
dwell portions are located diametrically opposite from each other,
each positioned symmetrically around a midpoint of each of the
concave portions of the peripheral race 158. At times during
operation when the wheels 156 are traversing the dwell portions of
the cupping cam 160, the punches remain stationary in the retracted
position enabling advancement of additional stock sheet material
into the press. The feeders 202 that advance the stock material
into the press can advantageously also be operated by servomotors
(not shown) that act to selectively advance the sheet material.
Operation of the feeders 202 can also be coordinated with the
operation of the other servomotors of the press.
[0031] During operation, the one or more punches 140 are lowered
such that a leading edge 306 of each punch 140 makes contact with
the workpiece. Each punch 140 pushes each workpiece or blank
through one or more forming dies 308 that operate to deform the
blank, wrap the blank around the leading edge 306 of the punch 140,
and form a cup. One or more ejectors 310 that are located on a
distal edge of a forming cavity 312, operate to eject the cup as
the punches 140 begin to retract after having reached a maximum
extended position. The forming cavities 312 are defined within the
lower die 137. In the embodiment shown, the ejectors 310 are
spring-loaded and act to "peel" each formed cup off each punch 140.
Subsequently, the blanking die 106 is raised from the cutting
position to the rest position, additional sheet material is fed
into the slot 108 by feeders 202, and the two-stage process of
blanking and forming is repeated. During the forming operation and
while each punch 140 is being extended, the leading edge 306 of
each punch enters each respective cavity 312.
[0032] A block diagram of a cupping press system 400 in accordance
with the disclosure is shown in FIG. 4. The cupping press system
400 includes a blanking portion 402, a forming portion 404, and a
controller 406. The blanking portion 402 includes a servomotor 408
that is operatively connected to a die 410 through a first
transmission arrangement 411. The servomotor 408 operates to move
the die 410 reciprocally such that blanks are cut from a sheet or
strip of material 412. A second operation performed by the forming
portion 404 forms the blanks into cups. The forming portion 404
includes one or more punches 414 that yield a corresponding number
of cups. The forming portion 404 includes a second servomotor 416
that is operatively collected to the punches 414 through a second
transmission arrangement 415. In an alternate embodiment, one or
more additional servomotors 418 (shown in dotted line) may each be
connected to one or more of the punches 414.
[0033] The controller 406 is operatively connected to the first
servomotor 408 and to the second servomotor 416. One or more
position sensors 420 may be connected to various components of the
press system 400. In the embodiment shown, various alternative
placements are presented for positioning of one or more sensors
420. As can be appreciated, the controller 406 can be configured to
receive as few as one input from a position sensor, but more than
one possible position sensors are presented herein. The various
locations for the position sensors 420 are meant solely for
illustration and should not be considered as limiting. Other
locations for position sensors that permit measurement of any
position that enables the controller to operate and synchronize the
first servomotor 408 and the second servomotor 416 are
contemplated. The various locations shown that are suitable for
accommodating a position sensor 420 include, for example, an output
shaft of the first servomotor 408, the first transmission
arrangement 411, the die 410, an output shaft of the second
servomotor 416, the second transmission arrangement 415, and the
punches 414. Advantageously, a position sensor 420 can be
integrated with each servomotor 408 and 416 and operate to relay a
digital signal representing a position of each of the servomotors
408 and 416 to the controller 620.
[0034] Operation of a cupping press by use of one or more
servomotors to drive the various portions of the press is
advantageously enabled by the synchronization of operation between
the motors by a controller. In the past, presses operating by
either hydraulic or mechanical power required other means of
synchronization that depended primarily on mechanical arrangements
of components, such as gear systems, belts, or chains. By use of
servomotors in accordance with the disclosure, different portions
of the press can operate independently in a coordinated fashion
under the supervision and control of an electronic controller. This
independent configuration can allow for better accessibility for
removing completed work-product out of the press as compared to
existing presses. For instance, the lack of massive structures that
operate and connect the first and second portions of the press
allows for removal of the formed cups from the press in any
direction or angle with respect to an entry direction of the stock
material into the press.
[0035] A flowchart for a method of operating a cupping press having
one or more servomotors is shown in FIG. 5. In operating a cupping
press having servomotors, the controller acquires a position signal
from a position sensor at step 502. The controller analyzes the
signal and generates a synchronization pulse or wave at step
504.
[0036] An operational position of a first portion of the press, for
example a blanking portion, is compared to the synchronization
pulse at step 506 so that the controller can determine a
synchronization state of the first portion of the press at step
508. At times when the controller determines that the first portion
of the press is not coordinated with the synchronization pulse, the
controller issues a corrective command to the first portion of the
press at step 510 to adjust the operation of the first portion and
bring the first portion in a coordinated state with the
synchronization pulse. This adjustment may be accomplished, for
example, by adjusting a power command to a first servomotor that
operates to accelerate, decelerate, or instantaneously retard the
operation for the first servomotor.
[0037] Following synchronization of the first portion of the press,
the controller compares an operational position of a second portion
of the press, for example the forming portion, with the
synchronization pulse at step 512. In instances when the controller
determines at step 514 that the second portion of the press is not
operating in coordination with either the synchronization pulse or
the first portion of the press, the controller can adjust operation
of the second portion at step 516 by, for example, adjusting a
power command to a second servomotor operating the second
portion.
[0038] The synchronization pulse or wave generated and used by the
controller may be a synchronization pulse received by the
controller externally, for example by sending to the controller a
signal generated by another device that is part of an assembly
process that includes the cupping press. Alternatively, the
synchronization pulse may be a position of one of the portions that
make up the press. In such an embodiment, the synchronization
effort of the controller is limited to synchronizing a remaining
portion of the press with the portion of the press used to set the
synchronization pace.
[0039] A block diagram of one embodiment for a control system 600
used to operate a cupping press is shown in FIG. 6. The control
system 600 is connected to a press 602 having a first portion 604
and a second portion 606. The first portion 604 includes a first
servomotor 608 operably disposed to operate a die 610. A first
position sensor 612 is included in the first portion 604 of the
press 602, and is configured to generate a position signal that
relates to the operational position or state of the first portion
604. The operational state of the first portion 604 can be
represented by any position parameter that is indicative of the
ongoing operation of the first portion 604 in real time. Similarly,
the second portion 606 includes a second servomotor 614 that
operates one or more punches 616. A second position sensor 618 is
configured to generate a position signal that relates to the
operational position of the second portion 606.
[0040] A controller 620 is configured to supervise and control the
operation of the first servomotor 608 and the second servomotor 614
is shown generally at 620. In the embodiment shown, the controller
620 includes a logic block 622. The logic block 622 has a first
input node 624 that is connected to the first position sensor 612
through a first communication line 625. A second input node 626 is
connected to the second position sensor 618 through a second
communication line 627. Finally, a third input node 628 is
configured to receive an external pulse or signal.
[0041] The input configurations shown for the first and second
input nodes 624 and 626 are optional and can selectively be used if
the press is operated to coordinate operation among the first and
second servomotors 608 and 614. Moreover, the external signal input
to the third input node 628 is optional and can advantageously be
used on a system that includes more than one devices, for example
the cupping press 602 and other presses that perform subsequent
forming, trimming, and/or painting operations on the pieces formed
by the press 602, that require coordination between the one or more
devices with the remaining devices in the system. In the case where
no external signal is available or desired, the logic block 622 can
generate an internal timing pulse to coordinate operation of the
various portions of the press 602. In such an embodiment,
parameters relevant to the timing pulse that is internally
generated in the logic block 622 can be input to the controller 620
by a user operating a user interface 630 that is operatively
connected to the controller 620. The user interface 630 can be
configured to allow data to be input to the controller, as well as
be capable of presenting operational information to the user.
[0042] The logic block 622 is adapted to output a timing pulse or
signal through at least one output node 632. The timing pulse from
the logic block 622 can selectively be based on one of feedback
from the first position sensor 612, the second position sensor 618,
the external pulse from node 628, and an internally generated
pulse. The timing pulse can be used to set a pace of operation for
the press 602 such that, for example a speed of operation of the
press 602, or a rate of application of force in the die 610 and/or
the punches 616, can be controlled with a high degree of precision
and accuracy.
[0043] Each portion 604 and 606 of the press 602 is respectively
operated by one of the first and second servomotors 608 and 614 as
described. The first servomotor 608 operates in response to a drive
signal from a first control 634. The first control 634 is included
in the controller 620 and has a pace-input node 636 that is adapted
to receive the timing pulse from the node 632. A signal from the
first position sensor 612 enters the first control 634 through a
feedback node 638 and is used for closed-loop control of the first
servomotor 608. The first control 634 is configured to send a drive
command through a first drive node 642. The drive command is
advantageously inclusive of any required timing considerations for
operation of the press 602. The drive command is also capable of
connecting the actual position of the first servomotor 608 with a
desired position based on the feedback from the first position
sensor 612. In the embodiment shown, the first control 634 can
include a proportional-integral-derivative (PID) control scheme
that uses closed-loop control algorithms to ensure that the actual
position of the first servomotor 608 closely tracks a desired
position in real time.
[0044] In similar fashion, the second servomotor 614 operates in
response to a drive signal from a second control 644. The second
control 644 has a pace-input node 646 that is adapted to receive
the timing pulse from the node 632. A signal from the second
position sensor 618 enters the second control 644 through a
feedback node 648. The second control 644 is configured to send a
drive command to the second servomotor 614 through a second drive
node 652. Additional controls may be included in the controller 620
as required. These additional controls may be used, for example, to
coordinate the operation of additional servomotors or actuators on
the press. These additional devices can operate, for example, to
feed sheet material into the press, collect and arrange finished
work-pieces from the press, operate linear actuators connected to
operator safety devices surrounding moving components of the press,
and so forth.
[0045] The control scheme described thus far is not to be
considered as limiting, and is solely presented as one possible
control scheme that can effectively coordinate and control the
operation of a cupping press in accordance with the disclosure. Any
control system or arrangement that is capable of coordinating and
operating one, two, or more servomotors that are associated with a
cupping press can advantageously accomplish operation of a press
that is capable of fine control in the speed, accuracy, and
efficiency of the press. The manufacture of components by use of
the press as described herein has been shown to reduce scrap rates,
decreased cycle time for production, increase yield, and improve
work-flow flexibility as compared to previous presses.
[0046] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. The terms "comprising,"
"having," and "including" are to be construed as open-ended terms
(i.e., meaning "including, but not limited to,") unless otherwise
noted. All methods described herein can be performed in any
suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illuminate the invention and does not
pose a limitation on the scope of the invention unless otherwise
claimed. No language in the specification should be construed as
indicating any non-claimed element as essential to the practice of
the invention.
[0047] Preferred embodiments of this invention are described
herein, including the best mode known to the inventors for carrying
out the invention. Variations of those preferred embodiments may
become apparent to those of ordinary skill in the art upon reading
the foregoing description. The inventors expect skilled artisans to
employ such variations as appropriate, and the inventors intend for
the invention to be practiced otherwise than as specifically
described herein. Accordingly, this invention includes all
modifications and equivalents of the subject matter recited in the
claims appended hereto as permitted by applicable law. Moreover,
any combination of the above-described elements in all possible
variations thereof is encompassed by the invention unless otherwise
indicated herein or otherwise clearly contradicted by context.
* * * * *