Title:
SERVO-DRIVEN CUPPING PRESS
Kind Code:
A1


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, US)
Application Number:
11/834336
Publication Date:
02/07/2008
Filing Date:
08/06/2007
Assignee:
Advanced Engineered Systems, Inc. (South Beloit, IL, US)
Primary Class:
International Classes:
B21D22/00
View Patent Images:
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Primary Examiner:
EKIERT, TERESA M
Attorney, Agent or Firm:
LEYDIG VOIT & MAYER, LTD (CHICAGO, IL, US)
Claims:
I claim:

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

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

The present invention generally relates to machines for forming metal, and, more particularly, to cupping presses.

BACKGROUND OF THE INVENTION

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.

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.

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

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.

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

FIG. 1 is an outline view in partial cross-section of a cupping press in accordance with the disclosure.

FIG. 2 is an outline view of a partial cross-section, from a different perspective, of a cupping press in accordance with the disclosure.

FIG. 3A is an enlarged view in partial cross section of components surrounding a die of a cupping press.

FIG. 3B is an enlarged view in partial cross section of components surrounding the cupping cam.

FIG. 4 is a block diagram of a cupping press having two portions in accordance with the disclosure.

FIG. 5 is a flowchart for a method of operating a cupping press having at least one servomotor in accordance with the description.

FIG. 6 is a functional diagram of a control method for operating a cupping press.

DETAILED DESCRIPTION

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 2¾ in. (7 μm). 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.





 
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