This invention relates to industrial equipment, and more particularly to machines configured to cut or punch workpieces, such as metal sheets.
As those of ordinary skill in the art will appreciate, punching machines may be employed to punch holes or other cut-outs from a workpiece (e.g., a metal sheet). Typically, punching machines include a tool bearing for a punching tool and a rotary/lifting drive, which moves the tool bearing back and forth along a lifting axis to a working area of the punching machine. Also, the tool bearing is rotatably adjustable about the lifting axis. The punching machine may also include a motor-driven spindle transmission provided with a drive control system. Typically, a rotary/lifting drive having two electric drive motors is provided for the tool bearing of a punching machine. Both drive motors may be arranged laterally next to a drive spindle, which in turn runs in the direction of a lifting axis of the tool bearing. One of the drive motors serves for workpiece punching and for that purpose is connected via a belt drive to a lifting spindle nut disposed on the drive spindle. By driving this spindle transmission in one direction of rotation, the tool bearing (and hence the attached punching tool) is moved with working strokes towards the workpiece to be processed and then by reversing the motor, the tool bearing is moved in the opposite direction. The second drive motor in a conventional punching machine is intended for rotary adjustment of the tool bearing and the punching tool. This drive motor is connected via another belt drive to enable rotation of the punching tool relative to the lifting axis. A more efficient punching tool would be desirable.
In one embodiment, the spindle transmission for stroke movement of the tool bearing in the radial direction lies inside the stator of the lifting drive motor. Additionally or alternatively, the driving element for rotary adjustment of the tool bearing is arranged radially inside the stator of the rotary drive motor. In the radial direction of the drive spindle the rotary/lifting drive according to the invention is consequently comparatively small. The resulting dimensions of the rotary/lifting drive in the axial direction of the drive spindle may also be relatively small.
In another possible embodiment, a compact construction of the complete machine may be achieved by minimizing the number of drive motors needed for the stroke movement and the rotary adjustment of the tool bearing. In this embodiment, a single rotary/lifting drive motor is provided, which serves both for movement of the tool bearing in the direction of the lifting axis and for rotary adjustment of the tool bearing about the lifting axis. This dual function of the rotary/lifting drive motor is facilitated by a controllable switching arrangement. This arrangement allows a driving element for the drive spindle to be connected to the rotary/lifting drive motor or to be disconnected from the rotary/lifting drive motor. In the one case, the rotary/lifting drive motor drives the driving element including the drive spindle about the spindle axis, which causes a rotary adjustment of the tool bearing about the lifting axis. If the driving element for the drive spindle and the rotary/lifting drive motor are disconnected from one another in respect of drive, then the rotary/lifting drive motor drives merely the lifting spindle nut. This results in the drive spindle being displaced in the direction of the spindle axis causing the tool bearing to be moved in the direction of the lifting axis.
Further, in some other possible embodiments, the rotary movement of the drive spindle is accompanied by a corresponding rotary movement of the lifting spindle nut disposed on the drive spindle. As such, rotary adjustment of the tool bearing can be performed without a relative rotary movement of the lifting spindle nut and drive spindle to avoid a movement of the tool bearing along the lifting axis.
In still another possible embodiment, there is provided a coupling slide between the motor-side lifting spindle nut and the driving element for the drive spindle to facilitate the connection or disconnection of the rotary/lifting drive motor and the driving element for the drive spindle. For example, in one embodiment, a force-fit connection may be employed. In another embodiment, an interlocking connection may be employed.
In yet another embodiment a rotation prevention system is provided for the drive spindle. More specifically, on disconnection of the driving element from the rotary/lifting drive motor, the rotation prevention system prevents rotation of the drive spindle about the spindle axis. The drive connection of the lifting spindle nut and rotary/lifting drive motor consequently affects an exclusively axial movement of the drive spindle, and, hence, a lifting movement of the tool bearing without associated rotary adjustment movement. For example, in one embodiment, the rotation prevention system of the drive spindle may include an anti-rotation slide that can be either fixed against rotation about the spindle axis or can be released for such a rotation.
In still another possible embodiment, a coupling/anti-rotation slide undertakes both the connection or disconnection in respect of drive of the rotary/lifting drive motor and the driving element for the drive spindle, as well as the establishment or termination of rotary protection of the drive spindle. In still another embodiment, a torque motor may be employed as either the lifting drive motor and/or the rotary drive motor. As will be appreciated, this type of motor enables even high torques to be transferred without interposed gearing as such embodiments employing a torque motor may be compact.
In yet another embodiment, there is provided, a punching machine including a tool bearing, a drive spindle coupled to the tool bearing, and a drive system configured to move the tool bearing axially along a lifting axis and to rotate the tool bearing about the lifting axis, the drive system including a motor system comprising a stator and a rotor internally coupled to the stator and a spindle nut coupled to the rotor and cooperating with the drive spindle, wherein the spindle nut is at least partially disposed within the stator.
In still another configuration, there is provided a punching machine including a tool bearing, a drive system configured to move the tool bearing axially along a lifting axis and to rotate the tool bearing about the lifting axis, the drive system including a motor system comprising a stator and a rotor internally coupled to the stator and a drive element coupled to the rotor and configured to transmit rotary movement from the rotor to the tool bearing, wherein the torque drive element is at least partially disposed within the stator.
In still another configuration, there is provided a punching machine including a tool bearing, a drive system configured to move the tool bearing axially along a lifting axis and to rotate the tool bearing about the lifting axis, the drive system including a motor comprising a first stator and a first rotor internally coupled to the first stator and a driving element engageable with the motor, wherein the driving element is configured to prevent rotation of the tool bearing about the lifting axis when the driving element is disengaged with the motor, such that the tool bearing is configured to move axially along the lifting axis without rotation when the driving element is disengaged with the motor, and wherein the driving element is configured to rotate the tool bearing about the lifting axis when the driving element is engaged with the motor.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference symbols in the various drawings indicate like elements.
As shown in
When machining a workpiece, (e.g., when punching sheets), the punch 6 cooperates with a punching lower tool (not shown) in the form of a die. In one embodiment, the punching lower tool may be integrated into a workpiece table 10, which in its turn mounted on the lower frame member 4 of the punching machine 1. The relative movements of the sheet that are required during machining of the workpiece relative to the punch 6 and the die are performed by a coordinate guide 12 housed in a gap area 11 of the machine frame 2.
As can be inferred in detail from FIGS. 2 to 5, the rotary/lifting drive 5 may include a drive housing 13 that has an electric rotary/lifting drive motor 14 of which the direction of rotation may be reversible. In one embodiment, the rotary/lifting drive motor 14 is a torque motor with a stator 15 fixed to the housing and with a rotor 16 rotating inside the stator 15 about the lifting axis 8. The rotor 16 of the rotary/lifting drive motor 14 may be directly and hence gearlessly connected to a lifting spindle nut 17, which sits on a drive spindle 18.
A spindle axis 19 of the drive spindle 18 may coincide with the lifting axis 8. In the axial direction, the lifting spindle nut 17 and the stator 15 of the rotary/lifting drive motor 14 are arranged mutually overlapping with its axial end facing towards the tool bearing 7. The lifting spindle nut 17 has a flange 20 at its axial end facing towards the tool bearing 7. A rolling-contact bearing 21 may be provided for rotary mounting of the lifting spindle nut 17 on the drive housing 13. By means of a first sensor arrangement 22 the direction of rotation and the angle of rotation of the lifting spindle nut 17 rotating about the lifting axis 8 (i.e. the spindle axis 19) may be detected. Jointly with the drive spindle 18, the lifting spindle nut 17 forms a spindle transmission 23, which in the embodiment illustrated is constructed as a ball screw transmission. Adjoining the drive spindle 18 towards the tool bearing 7, there is an axial extension 24 that is integral with the drive spindle 18. The axial extension 24 may be a circular cylindrical body from which radial fins 25 may project for part of the length of the axial extension 24. The radial fins 25 may have a substantially rectangular cross-section, as shown in
The driving element 27 surrounds the axial extension 24 and the drive spindle 18 concentrically. Its axial guide grooves 26 form, in cooperation with the radial fins 25 of the axial extension 24, an axial guide 28 for the axial extension 24 and the drive spindle 18 constructed in one piece therewith. A rolling-contact bearing 29 may be responsible for the rotary mounting of the driving element 27 and the axial extension 24 and the drive spindle 18 on the drive housing 13. A second sensor arrangement 30 serves to detect the rotated position of the axial extension 24 and of the tool bearing 7 provided thereon and of the punch 6 relative to the lifting axis 8.
The driving element 27 can either be connected in respect of drive to the rotary/lifting drive motor 14 or can be disconnected in respect of drive from the rotary/lifting drive motor 14 by means of a controllable switching arrangement 31. For that purpose, the controllable switching arrangement 31 may include a coupling/anti-rotation, slide 32, which is slidably guided in the axial direction on the outside of the driving element 27. Around the lifting axis 8, the coupling/anti-rotation slide 32 is supported on the driving element 27 secured against rotation by splines. A plurality of actuating slides 33, which are movably guided on the drive housing 13 in the direction of the lifting axis 8 and have a common pneumatic drive, serves for axial displacement of the coupling/anti-rotation slide 32.
The coupling/anti-rotation slide 32 engages with the free end of a flange 34 in the actuating slides 33. A radial flange face 35 of the flange 34 on the coupling/anti-rotation slide 32 lies opposite a radial flange face 36 on the flange 20 of the lifting spindle nut 17. On its side opposite from the radial flange face 35, the flange 34 of the coupling/anti-rotation slide 32 is provided with a further radial flange face 37, which is associated with a bearing surface 38 on the drive housing 13.
Further, during operation, the radial flange face 37 on the coupling/anti-rotation slide 32 is supported on the bearing surface 38 of the drive housing 13. By virtue of the normal force acting on the radial flange face 37 of the coupling/anti-rotation slide 32 and the bearing surface 38 of the drive housing 13, the coupling/anti-rotation slide 32 is fixed on the drive housing 13 against rotation about the lifting axis 8. By means of the coupling/anti-rotation slide 32, the driving element 27 and the axial extension 24 supported thereon locked against rotation and the drive spindle 18 is constructed in one piece with the extension 24 secured against rotation about the lifting axis 8. Accordingly, the coupling/anti-rotation slide 32 in cooperation with the driving element 27 and the drive housing 13 forms a rotation preventing system 39 for the drive spindle 18 with the drive housing 13 serving as an abutment for the driving element.
The rotation prevention system 39 prevents the drive spindle 18 from being carried with the lifting spindle nut 17 rotating about the lifting axis 8. Owing to the rotation of the lifting spindle nut 17 relative to the drive spindle 18, the drive spindle 18 is displaced in the direction of the lifting axis 8 jointly with the axial extension 24. The tool bearing 7 provided thereon and the punch 6 is held in the tool bearing 7. Depending on the direction of rotation of the lifting spindle nut 17, the tool bearing 7 and the punch 6 are lowered with a working stroke towards the workpiece to be machined or alternatively following a working stroke are retracted with respect to the workpiece with a reverse stroke.
In one embodiment, all the functions of the electric rotary/lifting drive 5 are numerically controlled. For example, the first sensor arrangement 22 and the second sensor arrangement 30 may be part of the numeric control system. The first sensor arrangement 22 may serve here for controlled execution of the working strokes and the reverse strokes of the punch 6 in the direction of the lifting axis 8. The second sensor arrangement 30 may serves for control of the rotary adjustment of the punch 6 about the lifting axis 8. In one embodiment, the rotary adjustment of the punch 6 encompasses a corresponding rotary adjustment of the die co-operating with the punch 6.
The driving element 77 supports an axial extension 74 that may be formed in one piece with a drive spindle 68. Unlike the axial extension 24 according to FIGS. 2 to 5, in one embodiment, the axial extension 74 includes a hollow cylinder. The axial extension 74 may engage with radial fins 75 in axial guide grooves 76 on the driving element 77. Together, the radial fins 75 on the axial extension 74 and the axial guide grooves 76 on the driving element 77 form an axial guide 78 for the axial extension 74 and the drive spindle 68 formed in one piece therewith.
A lifting spindle nut 67 is located on the drive spindle 68. The lifting spindle nut 67 is rotatable about the lifting axis 8 and (may be mounted) in the direction of the lifting axis. In one embodiment, the lifting spindle nut 67 is connected to a rotor 66b of the lifting drive motor 64b without interposed gearing. Associated with the rotor 66b is a stator 65b of the lifting drive motor 64b. A spindle axis 19 of the drive spindle 68 coincides with the lifting axis 8. Unlike the drive spindle 18 according to FIGS. 2 to 5, the drive spindle 68 may take the form of a hollow spindle.
The tool bearing 7 with the punch 6 may also be arranged on a ram 81, which is fixed in the axial seat of the drive spindle 68. The lifting spindle nut 67 and the drive spindle 68 form a spindle transmission 73, which like the spindle transmission 23 (FIGS. 2 to 5), may be in the form of a ball screw transmission. In the direction of the lifting axis 8 and in the direction of the spindle axis 19 respectively, the lifting spindle nut 67 and the stator 65b of the lifting drive motor 64b are arranged mutually overlapping. Furthermore, the driving element 77 and the stator 65a of the rotary drive motor 64a may also be overlapping.
For punching workpieces, the lifting drive motor 64b may be operated. The lifting spindle nut 67 rotating jointly with the rotor 66b of the lifting drive motor 64b drives the drive spindle 68 in the direction of the lifting axis 8. Depending on the direction of rotation of the lifting spindle nut 67, the drive spindle 68 (and with it the tool bearing 7 plus the punch 6) is lowered towards the workpiece to be machined or is retracted with respect to the machined workpiece. The rotary drive motor 64a is off during punching operation of the electric rotary/lifting drive 55. When the rotary drive motor 64a is off, the rotor 66a is blocked in the direction of rotation from rotation about the lifting axis 8. The same applies to the driving element 77, which is supported with positive locking on the rotor 66a. The off-state rotary drive motor 64a jointly with the driving element 77 prevents rotation of the drive spindle 68 moving in the axial direction.
To change the rotary adjustment of the tool bearing 7 and of the punch 6 relative to the lifting axis 8, the rotary drive motor 64a and the lifting drive motor 64b are operated in the same direction of rotation and at the same speed of rotation. The rotor 66a of the rotary drive motor 64a in the process entrains the axial extension 74, and by way of this the drive spindle 68, and the lifting drive motor 64b entrains the lifting spindle nut 67 in the relevant direction of rotation through the desired angle of rotation. In this manner, the rotary adjustment of the tool bearing 7 and the punch 6 is changed, without a relative rotary movement of lifting spindle nut 67 and drive spindle 68 and, thus, an associated axial displacement of the drive spindle 68.
The functions of the electric rotary/lifting drive 55 may also be numerically controlled. Components of the numeric control include, amongst other things, sensors (not shown nor explained in detail) for detecting speed of rotation, rotated angle, and direction of rotation of the lifting spindle nut 67 and the drive spindle 68.
Both drive spindles 98a, 98b may be in the form of hollow spindles. On their inside, the drive spindles 98a, 98b receive a ram 111, at the workpiece-side end of which the tool bearing 7 with the punch 6 is provided. The drive spindles 98a, 98b are connected to the ram 111 to form a single structural unit. The lifting axis 8 of the rotary/lifting drive 85 coincides with a common spindle axis 19 of the drive spindles 98a, 98b. Together with the drive spindle 98a, the lifting spindle nut 97a may form a spindle transmission 103a, and together with the drive spindle 98b, the lifting spindle nut 97b may form a spindle transmission 103b. In one embodiment, the spindle transmissions 103a, 103b have oppositely directed threads, but are otherwise of identical construction.
For punching workpieces, the two drive motors 94a, 94b are operated at the same speed but in opposite directions. As a result, the drive spindles 98a, 98b and the tool bearing 7 and the punch 6 are displaced in the direction of the lifting axis 8. By virtue of the oppositely directed motor drive, the lifting spindle nut 97a and the drive motor 94a prevent rotation of the drive spindle 98b. The lifting spindle nut 97b and the drive motor 94b prevent rotation for the drive spindle 98a.
For rotary adjustment of the tool bearing 7 and the punch 6 about the lifting axis 8 and the spindle axis 19 respectively, the drive motors 94a, 94b are operated at corresponding speed and with identical direction of rotation. This results in a joint rotary movement of the lifting spindle nut 97a and the drive spindle 98a and of the lifting spindle nut 97b and the drive spindle 98b. There is little or no relative rotary movement between the lifting spindle nut 97a and the drive spindle 98a or between the lifting spindle nut 97b and the drive spindle 98b. In this state, the lifting spindle nuts 97a, 97b act as driving elements for the drive spindles 98a, 98b. As such, depending on the mode of operation, the drive motors 94a, 94b may form rotary drive motors or lifting drive motors. Additionally, an axial displacement of the drive spindles 98a, 98b and of the tool bearing 7 with the punch 6 with simultaneous change in the rotated position relative to the lifting axis 8 is also possible. For example, in one embodiment, this effect may be achieved by operating the drive motors 94a, 94b at different speeds.
Additional description of one or more of the features described above may be provided in commonly assigned U.S. patent application Ser. No. ______ entitled SPINDLE DRIVE SUPPORT, filed Nov. 27, 2006 (Our Ref.: 15540- 100001), and/or commonly assigned U.S. patent application Ser. No. ______, entitled COUNTER-ROTATING SPINDLE TRANSMISSION, filed Nov. 27, 2006 (Our Ref.: 15540-101001). Both of these applications are hereby incorporated by reference.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, in other embodiments other suitable motors or transmission types may be employed. Accordingly, other embodiments are within the scope of the following claims
Number | Date | Country | Kind |
---|---|---|---|
EP 04 012 523.9 | May 2004 | EP | regional |
This application is a continuation of, and claims priority under 35 U.S.C. §120 to PCT/EP2005/005636, filed on May 25, 2005, and claims priority under 35 U.S.C. §119 from European application EP 04 012 523.9, filed May 27, 2004. Both of these references are hereby incorporated by reference.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/EP05/05636 | May 2005 | US |
Child | 11563582 | Nov 2006 | US |