WO1993003893A1

WO1993003893A1 - Linear punch press

Info

Publication number: WO1993003893A1
Application number: PCT/US1992/006605
Authority: WO
Inventors: David C. Dunn
Original assignee: Dunn David C
Priority date: 1991-08-19
Filing date: 1992-08-10
Publication date: 1993-03-04
Also published as: AU2445992A; US5193426A

Abstract

A linear punch press (20) for punching sheet material is formed by an X axis central support frame (30) having a co-extensive laterally spaced parallel support table (28 - 28a) on either side. Medially its ends the central frame supports a die station (44) including fixed position punch and die adaptors (124 - 126) which respectively support a cooperating punch and die. A workpiece supporting and positioning frame (24) is longitudinally slidably supported by the central frame (30) and in turn supports a punch head (22) movable longitudinally of the central frame (30) within the workpiece frame (24). A Y axis conveyor drive (78) extends between and is slidably supported at one end by the respective support table (28 - 28a) and is connected at its other end with the workpiece positioning frame (24) for moving a workpiece transversely across the central support frame (30).

Description

LINEAR PUNCH PRESS Technical Field This invention relates to industrial sheet metal process- ing of work pieces and more particularly to an improvement in a linear punch press. Background Art Punch presses for processing heavy duty industrial sheet metal workpieces have progressed from the C-shaped frame con- figuration which was subject to misalignment as a result of the increase in size of workpieces and the necessity for elon- gating the arms forming the C-shape. The punching operation in such a machine' subjected the arms to misalignment, thus re- suiting in damage to punches and dies and/or the workpiece. Such punch presses have evolved to the D-shape or bridge frame in which the workpiece is moved on X and Y axes to a selected position under the bridge. However, such punching machines have usually been equipped with turret-type punching heads or cartridge-type punch and die sets moved into position with respect to a punching head or a ram. Both the turret-type and the cartridge-type die holding systems are subject to numerous disadvantages: such as the use of an alignment pin to align a punch and die; and, the use of gears, pulleys, chains and clutches, all having many wear points resulting in a misalignment of punches and dies as well as damaging a workpiece or structural components of the punch press. United States Patent 3,449,991, issued June 17, 1969, to Daniels is an example of a punch press utilizing turrets for guiding the tooling into position for punching by a ram means. United States Patent No. 4,503,741, issued March 12, 1985, to Hunter is an example of a bridge-type punching frame that features elongated sectionalized cartridges which carry the tooling and die cartridges and are moved together in a linear fashion. Disclosure of Invention An elongated horizontally disposed workpiece central frame is interposed in spaced parallel relation between two elongated coextensive workpiece support tables and forms the X axis for workpiece X Y axis movement. Medially its ends the central frame supports a punch station comprising a plurality of fixed position punch and die adaptors which respectively support cooperating punches and dies. A workpiece supporting and positioning frame for movement of the workpiece in the X axis direction is longitudinally slidably supported by the central frame and in turn supports a punch head moveable longitudinally of the central frame within the workpiece frame. A bridge frame extending between the respective workpiece support table and the workpiece frame are movable longitudinally of the central frame and support tables and respectively support Y axis conveyors for moving workpieces through the workpiece frame into position for work- piece punching by the punch head. The principal object of this invention is to provide an improved linear-type punch press having punch and die adaptors permanently mounted in a fixed position and a movable punching head processing a workpiece interposed between punches and dies. Brief Description of Drawings Figure 1 is a perspective view of the preferred embodiment of the linear punch press; Figure IA is a perspective view of another embodiment; Figure IB is a perspective view of a further embodiment; Figure 2 is a left end view of Fig. l; Figure 3 is a side elevational view of the punch press and its controller; Figure 4 is a top plan view; Figure 5 is a partially exploded perspective of the central ___

support frame; Figure 6 is a fragmentary perspective view, to a larger scale, of the die support with parts broken away for clarity and the die housing extended for die replacement; Figure 7 is a fragmentary cross section view to an enlarged scale of punch and die adaptors in their respective supports and illustrating, by phantom lines the relative position of a punch and die; Figure 8 is a perspective view, to a different scale, with parts broken away for clarity of the X and Y positioning frame; Figure 9 is an exploded perspective view of the Y axis frame and conveyor; Figure 10 is a partially exploded perspective view, to an enlarged scale, of the Y axis drive and clamps; Figure 11 is an enlarged front view, partially in cross section, of the punching head with the cover and other parts omitted for clarity; Figure 12 is a perspective view of one support table; and, Figure 13 is a fragmentary perspective view of a punch and die storage compartment with its door open. The Best Mode For Carrying Out The Invention The reference numeral 20 indicates the punch^' press as a whole, which principally comprises a punch head 22, X and Y axes positioning frame 24, a central support frame 30, support tables 28 and 28a, X axis servo drive and ball screw 26 and X axis punch head servo drive and ball screw 27. The support frame 30 (Fig. 5) consists of outer end base legs 40 and 40a and inner base legs 42 and 42a depending from and supporting a lower die support 34. End spacer plates 48 and 48a overlying the lower die support 34 support an upper punch support 38 and define a central frame opening 39 (Fig. 3) for the passage of workpieces, as presently explained. The outer base legs 40-40a and inner base legs 42-42a provide excellent rigidity and support for the lower die su- port 34 and upper punch support 38. A plurality of base pa- nels 36 extend between base legs 40-42, 42-42a, and 42a-40a, respectively. Linear guides 32 and 32a are secured to respective sides of the upper punch support 38 and the lower die support 34 for slidably supporting the positioning frame 24. A die housing 44 supported by transverse roller guides 56 and 56a (Fig. 6) is mounted on the lower die support 34 and held in place by a power driven plunger 46. A punch adaptor 124 (Fig. 7) is secured in fixed position to the upper punch support 38 and a die adaptor 126 is secured in fixed position to the die housing 44. Positive alignment of the punch adaptor 124 and the die adaptor 126 is assured by line drilling through the upper punch support 38 and the die housing 44. The die housing 44 moves on the transverse roller guides 56 and 56a^' (Fig. 6) and allows the die housing to move to either side of the lower die support 34 for installing or replacing dies and adaptors 126. After installing dies or adaptors the power cyl- inder 46 repositions the die housing so the die adaptors 126 are in line with the respective punch adaptor 124 for punching workpieces. The X and Y axes positioning frame 24 (Fig. 8) includes support sides 60L and 6OR secured, at one end, to respective depending outer surfaces of a generally H-shaped, in end view, X axis frame 50 normal to and centered at respective ends of slots 51, only one being shown, (Fig. 3). A plurality of vert- ical gussets 62 and horizontal gussets 64 respectively secure the top and sides of the support sides 60L and 6OR to the frame 50. A support 84 extends between the other ends of the support sides 60L and 60R. Workpiece repositioning clamps 54 and 54a are fastened to the exterior of the frame 50. A plurality of linear guides 80 are mounted on the upper inner surface of the frame 50 and a plurality of X axis linear guides 82 are secured in confronting relation on the inner surfaces of the lower part of the frame 50. The linear guides 82 are positioned to receive the slides 32-32a and accurately align and move the X and Y positioning frame 50 on the central support frame 30. An X axis servomotor and screw assembly 26 (Figs. 1 and 4) is mounted on support frame 30 for moving the workpiece posi- tioning frame 24. Y axis frame assembly 76 (Figs. 8 and 9) is secured be- tween the side supports 60L and 6OR. A conveyor 78 is rotat- — D —

able under and over the Y axis frame 76 and its ends are snapped together by a bar clamp 86. The Y axis drive screw 72 (Fig. 10) extends from a servomotor 74 through the conveyor 78 to a bearing 68 (Fig. 9). A block 66 (Fig. 10) on the clamp 86 receives the screw 72 for moving the conveyor 78. Linear slides 82a are secured to the depending surface of the outward end portion of the support sides 60L and 6OR for the purpose presently explained. The Y axis frame 76 includes front roller supports 88 and rear roller supports 90 connected in parallel spaced relation by linear guide supports 92 and 92a and center supports 94 and 94a. Front rollers 89 and 89a and rear rollers 91 and 91a are respectively mounted on the front and rear roll- er support 88 and 90. Y axis linear guides 70 and 70a are moun- ted on the linear guide supports 92 and 92a. The ball screw bearing 68 is mounted on the front roller support 88 opposite the front rollers. The conveyor 78 is formed by conventional juxtaposed aluminum slat extrusions joined to each other along their longitudinal side edges. The conveyor forming slats are man- ufactured by Alco Aluminum Extrusion and are available from aluminum supply outlets. The Y axis drive and workpiece clamp assembly 58 including the bar clamp 86 is supported by the li- near guides 70 and 70a. Brackets 98 and 98a (Fig. 10) having gripping jaws 96 and 96a and power cylinders 100 and 100a are assembled on respec- tive end portions of the bar clamp 86 to form workpiece clamp assemblies 106 and 106a. Nuts 102 and 102a, a screw 105 and a clamping handle 104 respectively adjustably secure the clamp assemblies to the bar clamp 86. Referring to Fig. 11, a direct current stepper motor 114 is axially mounted on a horizontal cam 120 journalled by bearings at one side of the depending end portion of a plate- like interposer 108 vertically reciprocated in a punch head housing 122. A plurality of interposer cams 116 are rotatable by the shaft 120 in cooperating downwardly open slots formed in the depending end portion of the interposer 108. A plurality of workpiece punching rams 118 are vertically slidable in bushings in the depending portion of the punch head housing 122. A second stepper motor 114a, cams 116a, and shaft 120a are similarly mounted in the other side of the interposer 108. The interposer 108 and punching ram 110 are coupled together and contained by the punching head housing 122. Staggered rows of punches are unnecessary since either cam 116 or 116a may be selected, therefore, a greater punch and die density may be utilized. Gibs 112 and 112a guide the respective sides of the interposer 108 and are secured to the walls of the punching head housing 122. An X axis servomotor and screw assembly 27 is mounted on the frame 24 for moving the punch head housing 122 in an X axis direction. All screws, support bearing guides, and slides with servomotor drive are available from NSK Corporation, 3861 Research Park Drive, Ann Arbor, Michigan USA 48108. The loading and unloading support tables 28 and 28a (Figs. 1 and 12) are respectively formed by rectangular frames 144 having a plurality of overlying end panels 142 and side panels 138 and a horizontal support top 140. X and Y axes position- ing frame 24 linear guide supports 146 are longitudinally mounted on confronting surfaces of the tables 28 and 28a. The positioning frame linear guides 146 (Fig. 1) provide accurate alignment and support for the positioning frame 24 in the X axis direction by the cooperating X axis linear slides 82a (Fig. 8). The top 140 is provided with a hinged die door 148 covering a punch and die storage compartment. Another embodiment of a linear-type punch press is indi- cated at 20' (Fig. IA) in which a bridge-type frame 22' supporting a cooperating plurality of fixed position punches and dies extends transversely of a workpiece path. A workpiece positioning frame 24' is slidably supported by a work table 28' projecting laterally from the bridge frame 22'. Another embodiment of a linear-type punch press is indi- cated at 20" (Fig. IB) in which a similar bridge-type frame 22" supports a plurality of fixed position cooperating punches and dies. A work support table 28" similar to the work support tables 28 and 28a is positioned at one side of the bridge frame 22" in spaced-apart relation and supports one end of a work- piece positioning X Y axes frame 24" cooperatively supported in sliding relation by the bridge-type frame 22". Industrial Applicability The manner of loading and unloading the linear punch press with a workpiece, not shown, is identical to that of present type punch presses and may be manual or automatic. The X and Y positioning frame 24 is moved to the extreme left, as viewed in the drawings. The workpiece to be punched is placed on the support table 28 adjacent the workpiece clamp 106 and the re- positioning clamp 54. The workpiece is then moved into the support frame 30 and located adjacent the Y axis index cylinder 134 (Fig. 4). The workpiece clamp 106 and the repositioning clamp 54 are activated and grip the workpiece to prevent its unauthorized movement. Y axis servo drive 74 revolves the screw 72 and moves the bar clamp 86 and conveyor 78 as needed in the Y axis direction. The linear guides 70 and 70a keep the bar clamp 86 aligned. The repositioning clamp 54a and workpiece clamp 106a are similarly activated and grip the workpiece. When the "on" button is activated X axis index cylinder 134 and reposition- ing clamps 54 and 54a are released. The workpiece is moved to the first punch position by the Y axis servomotor drive 74 mov- ing the workpiece in the Y axis direction while the X axis ser- vomotor drive assembly 26 moves the positioning frame 24 in the X axis direction. The X axis linear slides 32 and 32a (Fig. 5) received by the X axis linear slides 82, on the frame 50 sides, (Fig. 8) prevents concave or convex bending of the punch sup- port 38 during workpiece punching action. The stepper motors 114 and 114a rotate the interposer cams 116 and 116a by the cam shafts 120 and 120a into position for striking the punch rams 118. The workpiece will be punched when either cam 116 or 116a is actuated. When cam 116 has been selected the punching ram cylinder 110 drives the interposer 108 downward striking punching ram 118 to produce the desired configuration in the workpiece. While the workpiece is moving in the X and Y axes direc- tions the punch head 22 is moved in the X axis direction by the X axis servomotor drive 27 through punch programmed positions. /03893 —8 _β—

When the Y axis servo drive 74 moves the workpiece to its max- imum forward position, repositioning clamps 54 and 54a grip the workpiece. Clamps 106 and 106a are released and moved to an outward position by the Y axis servo drive 74. The work- piece is then reclamped by the clamps 106 and 106a and reposi- tioning clamps 54 and 54a are released and the workpiece is moved in the Y axis direction through the support frame 30 by the conveyor 78. After the workpiece has been punched, the conveyor and workpiece clamps on the unload side of the frame 30 move the workpiece beyond the positioning frame 24 to re- leases it. A controller 31 (Fig. 3) is provided for controlling the operation of the punch press 20, The controller 31 is a four axis computer numerical control (CNC). The X and Y axes pos- itioning frame 24 and punch head 22 are closed loop servo de- sign. This insures that all machine drives are at the pre- scribed positions prior to punching a workpiece. The control- ler 31 also controls all other major machine functions such as the punching head 22, workpiece clamps 106 and 106a, reposi- tioning clamps 54 and 54a and various other automatic functions which are used on the punch press. The controller 31 continu- ously monitors all important machine functions and parameters and automatically diagnoses operating errors and/or out of limit conditions, disables affected components and displays the appropriate error message on a visual readout. The con- troller 31 is designed to operate on piece part data^' supplied from paper tape, an operators panel keyboard or a remote source such as another computer by a built in communication path.

Claims

Claims 1. A linear punch press for processing a workpiece, com- prising: upright elongated central frame means (30) having opposing side surfaces and having coextensive linear upper and lower slides (32) on said side surfaces; punch and die housing means (44) for supporting a plurality of fixed position punch and die adaptors intermediate the ends of said central frame means (30); a workpiece support table (28-28a) having a linear guide (146) coextensive with said central frame means (30) disposed in lateral parallel spaced-apart relation on respec- tive sides of said central frame means; X and Y axes workpiece positioning frame means (24) including conveyor means (78) extending transversely of and supported by said central frame means (30) and said support table linear guides (146); first and second motor means (26-74) for moving said positioning frame means (24) in an X axis direction and said conveyor means (78) in a y axis direction, respectively; punch driving head means (22) slidably supported for movement in an X axis direction within said positioning frame means (24); and, other motor means for aligning said punch head means (22) with selected punch positions. 2. The punch press according to claim 1 in which the work- piece positioning frame means includes: first pairs of work- piece clamps (54-54a) oveable with said positioning frame in an X axis direction; and, second pairs of workpiece clamps (106-106a) supported by and moveable with said conveyor means (78) in a Y axis direction. 3. The punch press according to claim 1 in which the punch head means includes: motor (114-114a) and cam means (116- 116a) for driving said punches through a workpiece. 4. The punch press according to claim 2 in which the punch head means includes: motor (114-114a) and cam means (116-116a) for driving punches through a workpiece. 5. A linear punch press for processing a workpiece, comprising: central frame means (30) having opposite sides; workpiece positioning frame means (24) on said central frame means (30) for moving a workpiece in one direction; punch and die housing means (38-44) for supporting a plurality of cooperating punch and die adaptors (124-126) in a fixed position intermediate the ends of said central frame means; punch driving head means (22) supported above said central frame means (30) for movement in a predetermined direction relative to a workpiece; workpiece support means (28) and (28a) including conveyor means (78) adjacent respective sides of said central frame means (30) for moving a workpiece in another direction; and, motor means (26-27-74-114) for moving said workpiece frame means (24), said conveyor means (78) and operating said punch driving head (22). 6. The linear punch press according to claim 5 and further including: cooperating guide means (32-32a-82) on said central frame means (30) and said workpiece frame means (24) for slid- ably supporting the latter relative to the central frame means; and, first motor means (26) for moving said workpiece frame means. 7. The linear punch press according to claim 6 in which said conveyor means includes: first clamp means (106) and (106a) on said conveyor (78) for gripping a workpiece; and, a second motor means (74) for rotating said conveyor. 8. The linear punch press according to claim 7 in which the workpiece frame means includes: second clamp means (54) and (54a) for gripping a workpiece during a workpiece punching op- eration. 9. The linear punch press according to claim 8 in which the punch head means includes: third motor means (27) for moving the punch head means (22) to a predetermined position relative to the workpiece frame means. 10. The linear punch press accordirτ to claim 9 in which the punch head means further includes: a plurality of punch rams (118) for forcing a like plurality of punches through a workpiece; a vertically reciprocable member (108) carried by said punch head (22) for movement toward and away from said punch rams (118); means (110) for vertically reciprocating said member; and, cam means (116) and (116a) supported by said member (108) for striking said punch rams. 11. The linear punch press according to claim 10 in which the workpiece support means includes: a workpiece support table (28) and (28a).