Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D28/00—Shaping by press-cutting; Perforating
  • B21D28/02—Punching blanks or articles with or without obtaining scrap; Notching
  • B21D28/12—Punching using rotatable carriers

Definitions

• the present invention relates to turret punch presses, for example those controlled by numerical methods which punch or stamp holes or impressions in- wor pieces.
• Such punch presses may be provided with tools of varying sizes and shapes which are adjustable for punching into the material wor piece at selected indexed or rotated orientations.
• machines have been provided with a rotating turret on each side of the workpiece, with one turret having several punch tools and the other having corresponding dies. It is usual to position the workpiece relative to the punch tool to be punched by means of numerically controlled computer means before punching. Often this is achieved by gripping and moving the workpiece relative to the frame and ram of the machine and translating it along two "XY" axis numerically controlled slides. The upper and lower turrets are rotated to position the correct punch tool and corresponding die below the ram before punching.
• machines have been provided with one motor to rotate both the upper and lower turrets in unison. Since the workpiece is positioned between the turrets and the mechanical drive has to be passed fully around the workpiece, either a right-angled gearbox arangement, or a sprocket wheel with shafts and chain drive arrangement is normally provided to ensure that the two turrets maintain the same angular rotation.
• EP 0215644 illustrates a turret punch press which requires at least three motors to provide rotation of turrets, punch tools and dies.
• the upper and lower turrets are each provided with a separate motor for rotating punch tool or die as the case may be.
• the motor is only capable of rotating one punch tool or die at a time. This requires that the motor has means for engaging or disengaging with punch tools or dies, and any punch tool or die which is not engaged with the motor has to be provided with a rotation brake so that the knowledge of the angular position of each punch tool or die can be maintained.
• a turret punch press comprising a frame, a motor, a turret mounted for rotation with respect to the frame, and a tool holder mounted for rotation with respect to the turret; characterised by selectable drive means arranged in a first position to cause the motor to drive the turret and in a second position to cause the motor to drive the tool holder.
• the axis of rotation of the turret with respect to the frame is preferably parallel to the axis of rotation of the tool holder with respect to the turret.
• the drive is desirably selectable between a first state in which the turret can rotate and the tool holder is rotatably fixed relative to the turret, and a second state in which the turret is held stationary and the tool holder can rotate with respect to turret.
• a first state in which the turret can rotate and the tool holder is rotatably fixed relative to the turret
• a second state in which the turret is held stationary and the tool holder can rotate with respect to turret.
• An epicyclic arrangement could be envisaged.
• the important feature is that the rotational speed of the tool holder relative to the turret differs between the two states. In this way, by using the two states, the tool holder can be positioned at any indexed angle and position on the turret relative to the frame.
• a clutch may be provided in the drive to select the first and second states. It is of course, not critical whether the clutch is activated to select the first state, or to select the second state.
• the clutch could be actuated by any convenient means, for example, an electromagnetic solenoid or by a hydraulic or pneumatic arrangement. Alternatively, a simple mechanical engagement might be suitable.
• the motor may rotate on a shaft with an axis concentric with that of the turret and the shaft may be arranged to drive a concentric gear ring which engages the gear on the periphery of the tool holder.
• the or each tool holder may be provided with a gear on its periphery which engages the gear ring. In this manner, knowledge of the rotational position of the gear ring or of a tool holder provides knowledge of the angular position of any component in the gear ring arrangement.
• the shaft is preferably connected through the clutch to the turret, with the shaft being rotationally fixed to the gear ring. Accordingly, the shaft is thus desirably permanently engaged with the gear ring, although this is not absolutely necessary. Alternatively, it is envisaged that the shaft could instead be connected through the clutch to the tool holder.
• the turret is arranged so that a punch tool held in or by the tool holder can be struck towards a workpiece by a ram, preferably a hydraulic ram
• the tool holder of the upper turret may hold the punch tool while the tool holder of the lower turret may hold an anvil or die.
• the punch is pressed through the workpiece against the anvil or die.
• the die may be configured specifically to correspond to a particular punch tool in the turret above, and it is preferred that the die is mounted in a lower turret which rotates co-axially with the above turret.
• Automatic control means may be provided to operate the turret punch press, for example a microprocessor.
• the control means ensures that the upper and lower turrets always rotate together, and that the corresponding upper tool holders and lower dies are always maintained in their correct rotational positions relative to the turret.
• Inhibiting means may be provided to inhibit actuation of an operating ram in the event that the upper tool holder and the lower die which are to be used are not in position.
• the control means may conveniently actuate one motor for movement of the upper turret and tool holders, and a second motor for movement of the lower turret and dies or die holders.
• Feedback loops may be provided from one or both motors, and/or the positions of the turrets and/or tool holders, tools, die holders or dies to ensure that the upper and lower gearing arrangements always remain in synchronisation with each other.
• Figure 1 is a schematic representation of a turret punch press which is applicable to all three specific embodiments
• Figure 2 is a schematic representation of the drive, clutch and gear assembly of the first embodiment
• Figure 3 shows in detail the gears and clutch assembly of the first embodiment
• Figure 4 shows in detail the gears and clutch assembly of the second embodiment
• FIG. 5 is a schematic representation of the drive, clutch and gear assembly of the third embodiment;
• Figure 6 shows in detail the locking assembly mechanism of the third embodiment;
• FIG. 7 shows in detail the clutch assembly of the third embodiment.
• Figure 8 shows in detail, the turret back valve and locking valve seat assembly of the third embodiment.
• Figure 1 is a schematic illustration of a turrent punch press.
• the specific features shown in this figure, and the corresponding description, are applicable to all three detailed embodiments which are to be described later.
• the turret punch press of Figure 1 is assembled on a C-shaped frame, generally designated by the numeral 1.
• the frame comprises a lower bed 2 and a cantilevered overhead beam 3.
• Mounted for rotation respectively to the overhead beam 3 and the bed 2 are upper and lower rotatable turrets 4, 14.
• the upper turret 4 is mounted for rotation on a shaft 8 which itself is driven via a reduction gearbox 7 by a servomotor 5 and encoder 6.
• Above the upper turret 4 is a gear ring 9 which is fixedly secured with respect to the shaft 8 for rotation therewith.
• a plurality of punching tools 12, for example punch assemblies, are located in corresponding upper tool holders 10 which are mounted for rotation on the upper turret 4.
• a clutch (not shown) is provided between the shaft 8 and the upper turret 4.
• the upper turret 4 is fixedly secured to the shaft and to the gear ring 9 and accordingly rotates when they rotate. In this way, by rotation of the shaft 8, a selected punch assembly 12 can be rotated into the operating position beneath a ram 13.
• the ram 13 is operated by a controllable impact device 28.
• the teeth of the gear ring 9 are in permanent meshing engagement with corresponding teeth of the various rotating upper tool holders 10.
• rotation of the shaft 8 simply causes rotation of the .gear ring 9 and accordingly rotation of the punch assemblies about their own axes.
• a selected punch assembly which has already been positioned beneath the ram 13 can be rotated about its own axis to provide (for example) square holes punched into a workpiece at a variety of different orientations.
• a workpiece 23 to be punched is positioned between the upper and lower turrets 4, 14.
• the workpiece is manoeuvered into position by a feeding mechanism 24 having separate controls and clamps 25 on the X and Y axes.
• the workpiece 23 is moved by the feeding mechanism into the correct place for punching to occur immediately beneath the ram 13, and it is then held in that position.
• the appropriate punch assembly 12 and corresponding die 22 are then moved into the operating position by actuating both the upper and lower motors 5, 15 and the corresponding upper and lower clutches (not shown) .
• the upper and lower turrents 4, 14 are locked in position by means of upper and lower locking mechanisms 26, 27.
• the clutches are then deactivated so that continued operation of the motors 5, 15 causes rotation of the punch and die about their own axes.
• both are correctly positioned, the workpiece 23 is punched by operation of the ram 13.
• an electronic control unit 29 This is desirably a microcomputer providing numerical control.
• the unit 29 ensures that the ram 13 is actuated only when it has received confirmation that the workpiece 23 is in position, the upper and lower turrets 4, 14 are properly locked in place, and that the selected punch 12 and corresponding die 22 have been correctly indexed and then rotated about their own axes so as to be in the desired position for punching.
• FIG. 2 schematically shows the arrangement of drive members for the first embodiment.
• the upper and lower gear rings 9, 19 are fixedly secured to the upper and lower shafts 8, 18 for rotation therewith.
• the upper and lower turrets 4, 14 are journalled for rotation on their respective shafts 8, 18.
• the teeth of the gear rings 9, 19 remain permanently engaged with corresponding teeth of planetary gears of the upper punches 12 and the lower dies 22.
• Upper and lower electromagnetic clutches are provided respectively to couple the upper turret 4 to the upper shaft 8 and the lower turrent 14 to the lower shaft 18. The couplings are effected when the respective coils 11, 21 of the electromagnetic clutches are actuated.
• the coil 11 of the upper electromagnetic clutch is contained within a retaining ring 32 which itself is permanently coupled to the fixed upper beam 3.
• the gear ring 9 is keyed at 34 to the drive shaft 8 so as to rotate therewith.
• a friction disk 33 In a circumferential groove running around the lower surface of the gear ring 9 is a friction disk 33.
• the clutch plate 30 is very slightly moveable in the vertical plane and has beneath it a wafer spring 35. The clutch plate 30 is screwed at intervals to the wafer spring 35 which in turn is screwed at intervals to the upper turret 4 to prevent the clutch plate rotating relative to the upper turret when the electromagnetic clutch is applied.
• the lower clutch mechanism is virtually identical, comprising as it does a lower electromagnetic clutch * having a coil 21. There is also a corresponding friction disk 37, clutch plate 31 and wafer spring 39.
• the lower gear ring 19 is fixedly coupled to the lower shaft 18 by means of a key 38.
• the electromagnetic clutch arrangement is replaced by a pneumatic clutch.
• a pneumatic clutch has the advantage that the working parts of the turret punch press are not then affected by the residual magnetism that electromagnetic clutches are liable to produce.
• the pneumatic clutch is here contained within an annular support 32' which is permanently secured to the fixed upper beam 3.
• the air for operating the clutch enters via one or more blind bores 50, and passes down through a plurality of vertical bores 52 to the upper surface of a continuous annular seal 55 which is itself secured to a continuous annular thrust bearing 54.
• This bearing has a plurality of downwardly extending spigots 56, spaced around the periphery, these spigots passing through corresponding spaced bores in the gear ring 9. Screwed into the lower ends of these spigots is a continuous annular wedge 58.
• Disk springs 60 located between a lower shoulder of the spigots 56 and the gear ring 9 ensure that in the rest position the wedge 58 is biased upwardly against the lower surface of the gear ring.
• the wedge 58 is located within a correspondingly wedge-shaped recess in a clutch plate 30'.
• the thrust plate is separated into four, six or eight separate sections around the periphery, each section being very slightly moveable in a radial direction. Accordingly, the sections can move slightly to take up slight machining errors in the surface of the wedge and/or the recess into which the wedge fits.
• the clutch plate 30' it would be possible for the clutch plate 30' to be continuous, and the wedge 58 to be split up into a plurality of separate sections.
• the gear ring 9 is shown as being manufactured from two separate sections 9a, 9b, which are simply screwed together.
• a continuous gear ring could also be used here, as was shown in Figure 3.
• a two-part gear ring could also be used in Figure 3.
• the lower gear ring arrangements for this embodiment will not be described since, as will be appreciated, they resemble the arrangements shown in Figure 4 in the same way as the lower part of Figure 3 resembles the upper part of Figure 3.
• This embodiment like the embodiment for Figure 2, features an air clutch but in this case the air for operating the clutch is fed into the system via the upper and lower locking pins 40, 41.
• FIG. 5 shows a schematic arrangement of the drive mechanism.
• connections beteen the upper turrent 4 and the gear ring 9, and the lower turret 14 and the lower gear ring 19, are effected by respective air-controlled clutch plates 60, 61. These extend circumferentially of the turrets and, when in their operational position, press respectively upwardly, and downwardly on the lower and upper surfaces of the gear rings 9 and 19.
• Air pressure is provided by a plurality of circumferentially arranged pneumatic cylinders 65, 69 which are coupled via radial bores to upper and lower ring channels 63, 67. These in turn, are coupled by further radial channels 62, 66 to valves 76, 77, the seats of which are the locking recesses 42', 43' into which are received the corresponding locking pins 40' and 41'.
• the locking pins 40', 41' in this case are hollow, and are arranged to supply air via control valves 81, 91.
• the actuation of the pins themselves is effected by further air-operated control valves 74, 75.
• control valves 74, 75 are actuated to insert the pins into the corresponding recesses.
• the control valves 81, 91 are then actuated causing air to flow through the pins, via the valves 76, 77 to the respective upper and lower pneumatic cylinders 65, 61. This forces the clutch plates 60, 61 away from the gear rings 9, 19 (as will be described in more detail below) so allowing the gear rings to rotate independently of the turrets.
• Figure 6 shows the upper locking mechanism 26 in more detail. It comprises a stepped cylinder 78 having within it a hollow locking pin 40' with an outwardly-extending piston flange 80.
• the piston is biased to its inoperative or rectracted position by means of a spring 84 which extends between the piston flange 80 and a front cover 89.
• the cover is held in position by screws 82 and includes an O ring seal 83 around to the periphery of the pin.
• a pressure-balancing aperture 85 extends from one side of the cover to the other.
• Actuation of the pin 40' is,effected by supplying air via a control valve 74 through a bore in the side of the cylinder 78 to the rear of the piston flange 80.
• a second control valve 81 When the pin is in position, and sealed against the surface of the recess 42' ( Figure 5) , further air pressure is supplied via a second control valve 81, this pressure passing via the longitudinal bore within the pin to the conduits within the turre
• the lower locking mechanism is similar.
• FIG. 7 shows in more detail the actual clutch mechanism.
• the circumferential friction disk 60 positioned in a corresponding annular cavity in the upper surface of the turret 4 , has screwed to it by screws 104 a plurality of circumferentially spaced shanks 100. The lower ends of these shanks are connected by a circumferentially continuous diaphragm 99. Air pressure within the cylinders 65 is prevented from reaching the clutch plate 60 by virtue of a fixed intermediate insert 96 which has seals 97 allowing the shanks 100 to move slightly up and down, taking with them, of course, the clutch plate 60.
• each of the shanks 100 on the other side of the diaphragm, there is a smaller diameter cylinder containing a shouldered spigot 101 and a biasing spring 102.
• An air equalising vent 103 extends between each of the cylinders 105 and the atmosphere.
• Figure 8 shows in detail the locking pin seat assembly of the upper turret 4.
• the turret includes a plurality of circumferentially spaced recesses 42' which define seats for the locking pin 40'.
• a back valve generally designated by the numeral 126 which connects the bore of the pin 40' with the internal channel 62.
• the back valve 126 has a biasing spring 119 which acts to press a moveable valve member 128 into sealing contact with an annular seal 110 on the turret.
• the locking pin 40' When the locking pin 40' is engaged with one of the seats 42', it presses against the forward end of the valve member 128, so mechanically opening the valve. In this position, air can pass from the pin 40' to the air clutch ( Figure 7) .

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Punching Or Piercing (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26295902

Family Applications (1)

Country Status (3)

Family Cites Families (6)

• 1990
  • 1990-09-11 EP EP19900913525 patent/EP0491774A1/de not_active Withdrawn
  • 1990-09-11 WO PCT/GB1990/001403 patent/WO1991003336A1/en not_active Application Discontinuation
  • 1990-09-11 AU AU63421/90A patent/AU6342190A/en not_active Abandoned

Non-Patent Citations (1)

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