Patent Application
20220143666
The invention relates to a tool and to a method for processing plate-like workpieces, in particular metal sheets.
A machine tool is known from our commonly assigned German published patent application DE 10 2016 119 435 A1. The machine tool is configured for processing plate-shaped or plate-like workpieces, in particular metal sheets. The tools are actuated by the machine tool for the purposes of stamping and punching. The tool comprises an upper tool, which is movable by means of a stroke drive apparatus along a stroke axis in the direction of a workpiece for processing and in the opposite direction and is displaceable by means of a drive arrangement along the upper positioning axis. Furthermore, a lower tool is provided which is aligned with the upper tool and which is movable by means of a stroke drive apparatus along a lower stroke axis in the direction of the upper tool and is positionable along a lower positioning axis which is oriented perpendicular to the position axis of the upper tool. The drive arrangements are actuated, in order to move the upper and lower tool, by means of a controller. The upper tool comprises a processing tool that is inclined relative to a positioning axis of the upper tool. Two cutting edges oriented parallel to one another are provided on the processing tool in order, for example, to cut a sheet-metal tab that has been bent up at an angle or to produce a side surface oriented obliquely with respect to the plane of the plate-like workpiece.
Our commonly assigned German published patent application DE 10 2016 119 457 A1 furthermore discloses a machine tool of said type. To produce bends or angled bends on a workpiece part of a plate-like workpiece, use is made of a tool that is composed of an upper tool and a lower tool. The upper tool comprises a clamping shank and a main body and a processing tool, which comprises a bending edge. Said processing tool is provided on the main body so as to be situated opposite the clamping shank. Here, the bending edge of the processing tool preferably lies outside a projection area of the main body of the upper tool, which projection area is formed perpendicular to the position axis and as viewed in the stroke direction. The lower tool comprises a main body and a bearing block arranged rotatably thereon, on which bearing block a partially cylindrical angled-bend-forming bolt is mounted in a corresponding recess and about an axis of rotation. Here, the axis of rotation of the angled-bend-forming bolt extends parallel to the bending axis. To produce an angled bend, the bending edge of the upper tool is aligned with the angled-bend-forming bolt. By means of a purely displacement movement of the bending edge in a stroke direction along the position axis, 90° angled bending is made possible, the angled-bend-forming bolt performing a rotational movement in order to set the workpiece part upright in relation to the bending edge.
It is accordingly an object of the invention to provide a machine tool and a related method which overcome a variety disadvantages associated with the heretofore-known devices and methods of this general type and which provides for a tool and a method for processing plate-shaped workpieces, by means of which increased flexibility in the processing of the workpieces, in particular for the introduction of a bend contour, is made possible.
With the above and other objects in view there is provided, in accordance with the invention, a tool for processing plate-shaped workpieces, such as sheet metal. The tool comprises:
an upper tool and a lower tool movably disposed toward one another for processing a workpiece arranged between said upper and lower tools;
said upper tool having a clamping shank and a main body, arranged on a common position axis, and a processing tool mounted to said main body opposite said clamping shank;
said processing tool of said upper tool having at least one bending edge;
said lower tool having a main body with a bearing surface for the workpiece and an opening formed within said bearing surface;
said main body of said lower tool having at least one counterpart bending edge fixedly formed thereon and positioned in said opening formed in said bearing surface; and
said bearing surface being displaceable relative to said counterpart bending edge to enable said counterpart bending edge to protrude from said opening formed in said bearing surface.
In other words, the objects of the invention are achieved by a tool for processing plate-like workpieces, in the case of which the upper tool comprises a processing tool with at least one bending edge and the lower tool comprises a main body with at least one counterpart bending edge provided fixedly on the main body, the main body comprising a bearing surface with a cutout that surrounds the counterpart bending edge, and the bearing surface being displaceable relative to the counterpart bending edge such that, when load is exerted on the bearing surface, the counterpart bending edge, in the cutout, projects relative to the bearing surface. This tool allows different bend contours to be produced. By means of this tool, the workpiece part is bent upward relative to the plate-like workpiece. So-called pivoting bending can be generated. Here, different bend contours can be realized, the course of which also differs from a 90° angle bend.
Angled bends of 90°, or overbending, can also be produced on a workpiece part by means of such a tool. A folded edge or a fold can also be generated. Furthermore, such a tool allows so-called endless bending, or bending with multiple incremental bending steps, in order to produce greater bend radii several times greater than a radius of the bending edge and/or counterpart bending edge.
Preferably, the bearing surface and a ram surface of the counterpart bending edge, which is assigned to the opening of the bearing surface on the lower tool, are aligned flush with the bearing surface in an initial position. Straightforward and disruption-free positioning of an unprocessed plate-like workpiece, or at least partially plate-like workpiece, on the lower tool can thus be made possible.
The bending edge of the upper tool and the counterpart bending edge of the lower tool are preferably of equal length. In this way, bending or angled bending which takes place in accordance with the length of the bending edge and counterpart bending edge can be made possible by means of one stroke. It is also possible for the bending edge on the upper tool to be configured to be shorter than the counterpart bending edge. This can be advantageous in particular in the case of an incremental bending of plate-like workpieces.
Furthermore, the bending edge of the upper tool and the counterpart bending edge of the lower tool preferably subsequently each have a surface which is inclined relative to the ram surface and which is oriented at an angle of less than 90° with respect to the ram surface. In this way, both the bending edge and the counterpart bending edge have an undercut as viewed in relation to the ram surface, whereby the processing range for the introduction of a bend contour is increased.
According to a first embodiment, the upper tool may have a processing tool with a bending edge which lies within a projection area which is formed perpendicular to the position axis and as viewed in the stroke direction. The bending edge advantageously crosses the positioning axis. Here, in the case of 90° angled bending, the length of the limb that is bent at an angle on the workpiece part is limited by the spacing of the ram surface of the processing tool to the main body. Alternatively, the bending edge of the processing tool on the upper tool may be provided outside the projection area of the main body, the projection area being formed perpendicular to the position axis and, as viewed in the stroke direction, by the periphery of the main body. In this way, the length for an angled part of the workpiece part is considerably increased, because that section of the workpiece part which is oriented upward as a result of the pivoting bending or the angled bending can be moved past the main body of the upper tool. If the width of the workpiece for processing corresponds to the length of the bending edge, a pivoting bending movement or angled bending can extend as far as a tool receptacle which is only partially surrounded by a deflecting collar, which deflecting collar is oriented in the direction of the bending edge of the tool and is interrupted in said region.
With the above and other objects in view there is also provided, in accordance with the invention, a method for processing a plate-shaped workpiece, such as a sheet metal sheet. The method comprising: providing an upper tool, which is movable by a stroke drive device along a stroke axis in a Z direction and in a direction of the workpiece for processing by the upper tool and in an opposite direction, and which is positionable along an upper positioning axis running perpendicular to the stroke axis in a Y direction, and moving the upper tool along the upper positioning direction by a drive arrangement;
providing a lower tool, which is aligned with the upper tool and is positionable along a lower positioning axis which points in the Y direction and which is oriented perpendicular to the stroke axis of the upper tool, and moving the lower tool along the lower positioning axis by a drive arrangement;
actuating the drive arrangements by a controller for moving the upper and lower tools relative to one another;
providing a tool according to claim 1 for processing the workpiece, and positioning a workpiece part of the plate-shaped workpiece relative to the bearing surface of the lower tool;
aligning the bending edge of the upper tool and the counterpart bending edge of the lower tool with one another;
transferring at least one of the bending edge or the counterpart bending edge, by way of a stroke movement in the Z direction, into a first working position in which the bending edge is positioned, as viewed in the Z direction, with a spacing equal to a thickness of the workpiece, and as viewed in the Y direction, at least with a spacing of the thickness of the workpiece, relative to the counterpart bending edge; and controlling a subsequent displacement movement of the bending edge and the counterpart bending edge by moving at least one of the counterpart bending edge or the bending edge past one another by superposition of the displacement movements in the Z direction and in the Y direction.
In other words, the objects of the invention are achieved by means of a method for processing plate-like workpieces, in which a tool according to any one of the embodiments described above is used, and the bending edge on the upper tool and the counterpart bending edge on the lower tool are, prior to the commencement of a pivoting bending process, transferred into a first working position in which the bending edge is positioned, as viewed in a Z direction, with the spacing of the thickness of the workpiece to the counterpart bending edge, and as viewed in a Y direction, at least with the spacing of the thickness of the workpiece to the counterpart bending edge, and the bending edge and/or the counterpart bending edge are subsequently set in a displacement movement, by means of which the bending edge and the counterpart bending edge are moved past one another until an end position for the removal of the workpiece part is reached. Thus, with progressive displacement movement from the first working position to the end position, the counterpart bending edge on the lower tool projects relative to the bearing surface in order to perform the pivoting bending movement. As a result of the superposition of a displacement movement in the Z direction and in the Y direction, targeted control of the tool to introduce a bend contour can be made possible. A large number of different bend contours can be introduced by means of this superposed displacement movement. In particular, pivoting bending can be implemented.
It is preferably the case that, during a pivoting bending process, the counterpart bending edge is static and the bending edge is driven on a curved path. In this way, proceeding from the first working position, the upper tool is driven with a superposed displacement movement in the Z and Y directions, such that a curved path is generated, wherein, in particular toward the end of the pivoting bending step, the advancing movement in the Z direction decreases and the displacement movement in the Y direction increases. Alternatively, the bending edge may be static and the counterpart bending edge may be driven on a curved path. An analogous description to that given in the case of the interchanged driving of the displacement movement of the bending edge relative to the counterpart bending edge applies here.
According to a further alternative embodiment of the method, the bending edge and the counterpart bending edge are both transferred from the first working position into an end position by being driven on a curved path. This also constitutes an embodiment for introducing bend contours.
A further preferred embodiment of the method provides that the displacement movement of the bending edge and/or that of the counterpart bending edge are driven several times in succession for incremental bending, each bending step comprising a bend angle on the workpiece part of less than 90°. In this way, it is possible to realize bend radii of different sizes that are all larger than a bend radius of the bending edge and/or counterpart bending edge.
A further advantageous embodiment of the method provides that a helical contour is introduced into a workpiece which has a Y-shaped cut layout. The Y-shaped cut layout of the workpiece has two arms which are positioned in a V shape with respect to one another. The helical contour can be formed through the introduction of multiple bending edges into the respective arm. The helical contour can have a greater or lesser diameter in a manner dependent on the bend angle.
A further advantageous embodiment of the method provides that, if a width of the workpiece part is greater than the length of the counterpart bending edge, multiple bending steps are introduced into the workpiece part in succession and along the same bending edge. In this way, by means of multiple strokes between the upper and the lower tool, a bending edge is generated which is greater than the length of the counterpart bending edge and/or of the bending edge.
A further advantageous embodiment for introducing a bending edge into the workpiece part, which bending edge is longer than the counterpart bending edge or bending edge of the tool, provides that the sequence of the bending steps of a subsequent bending edge in the workpiece is configured to be different in relation to the preceding bending edge of the workpiece. For example, the first stroke for a subsequent bending edge may be provided so as to be laterally offset by one position in relation to a first stroke of the bending step in the case of the preceding bending edge in the workpiece. A uniform contour can thus be introduced. This is advantageous in particular if relatively large bend radii are introduced by incremental bending.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a tool and a method for processing plate-shaped workpieces, in particular metal sheets, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
The machine tool 1 serves for the processing of plate-shaped or plate-like workpieces 10, which for the sake of simplicity are not illustrated in
The upper tool 11 is fixed in a tool receptacle at a lower end of a plunger 12. The plunger 12 is part of a stroke drive apparatus 13, by means of which the upper tool 11 can be moved in a stroke direction along a stroke axis 14. The stroke axis 14 runs in the direction of the Z axis of the coordinate system in a numerical controller 15, indicated in
The movement of the plunger 12 along the stroke axis 14 and the positioning of the stroke drive apparatus 13 along the positioning axis 16 are performed by means of a motor drive arrangement 17, in particular spindle drive arrangement, with a drive spindle 18 which runs in the direction of the positioning axis 16 and which is fixedly connected to the machine frame 2. During movements along the positioning axis 16, the stroke drive apparatus 13 is guided on three guide rails 19 of the upper frame member 3, of which two guide rails 19 can be seen in
The lower tool 9 is received so as to be movable along a lower positioning axis 25. This lower positioning axis 25 runs in the direction of the Y axis of the coordinate system of the numerical controller 15. The lower positioning axis 25 is preferably oriented parallel to the upper positioning axis 16. The lower tool 9 can, directly at the lower positioning axis 16, be moved along the positioning axis 25 by means of a motor drive arrangement 26. Alternatively or in addition, the lower tool 9 may also be provided on a stroke drive apparatus 27, which is movable along the lower positioning axis 25 by means of the motor drive arrangement 26. This drive arrangement 26 is preferably configured as a spindle drive arrangement. The lower stroke drive apparatus 27 may correspond in terms of construction to the upper stroke drive apparatus 13. The motor drive arrangement 26 may likewise correspond to the motor drive arrangement 17.
The lower stroke drive apparatus 27 is likewise displaceably mounted on guide rails 19, which are assigned to lower horizontal frame members 4. Guide shoes 20 of the stroke drive apparatus 27 run on the guide rails 19 such that the connection between the guide rails 19 and guide shoes 20 on the lower tool 9 can also accommodate a load acting in a vertical direction. Accordingly, the stroke drive apparatus 27 is also suspended on the machine frame 2 by means of the guide shoes 20 and the guide rails 19 and so as to be spaced apart from the guide rails 19 and guide shoes 20 of the upper stroke drive apparatus 13. The stroke drive apparatus 27 may also comprise a wedge mechanism 21 by means of which the situation or height of the lower tool 9 along the Z axis is adjustable.
The lower tool 9 likewise comprises a main body 41, which is suitable for being fixed in the machine-side lower tool receptacle with a defined rotational position, for example by means of at least one indexing element 42. Here, the lower tool 9 is rotatable about a position axis 48. This forms a longitudinal axis or longitudinal central axis of the main body 41.
The lower tool 9 has an opening 46 in a bearing surface 47, which is displaceable in terms of its situation, in particular in a Z direction, in relation to the main body 41. A counterpart bending edge 52 is positioned in said opening 46 of the bearing surface 47, which counterpart bending edge 52 is adjoined by a ram surface 51 which, in an initial position, is provided so as to be preferably flush with respect to the bearing surface 47.
The processing tool 37 on the upper tool 11 comprises one bending edge 45. A further bending edge or a punching edge may be provided opposite said bending edge 45. On the end side, the processing tool 37 comprises a ram surface 43, which transitions into the bending edge 45. An inclined surface 49 extends from the bending edge 45 in the direction of the main body 33 of the upper tool 11. The inclined surface 49 and the ram surface 43 are arranged at an angle of less than 90°. The bending edge 45 is formed at the transition region. The transition region is determined by the magnitude of the radius of the bending edge 45.
The bearing surface 47 is received in the main body 41 so as to be displaceable counter to the Z direction. Elastically flexible restoring elements 56 are preferably provided, which, after an exertion of load on the bearing surface 47 as a result of a displacement movement toward the main body 41, transfer said bearing surface 47 back into an initial position, as illustrated in
Proceeding from a starting position 61—shown in
During the transfer of the workpiece 10 from the working position as per
The starting point 81, the intermediate points 82 and the end point 83 on the lower tool 9 lie in a common straight line, that is to say the upper tool 11 and the lower tool 9 are moved past one another in parallel.
Such an upper tool 11 has the advantage that a length of that portion of the workpiece part 81 which is bent at an angle is greater than a spacing between the bending edge 45 and the underside of the main body 33.
In the exemplary embodiment shown in
These successive working steps n, n1, n2 . . . can be used in the case of bend segments 71 to form several further bend segments in succession. Alternatively, such an implementation of the working steps may for example also be implemented for a 90° angle bend.
A random selection and arrangement of the individual working steps n1, n2, n3 for each bend segment 71 is also possible, with the premise that two working steps of two successive bend segments 71 are not aligned directly one behind the other.
The introduction of several successive bend segments 71 may be implemented such that a helical contour can also be generated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2019 119 848.8 | Jul 2019 | DE | national |
This application is a continuation, under 35 U.S.C. § 120, of copending International Patent Application PCT/EP2020/070482, filed Jul. 20, 2020, which designated the United States; this application also claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 10 2019 119 848.8, filed Jul. 23, 2019; the prior applications are herewith incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2020/070482 | Jul 2020 | US |
| Child | 17582189 | US |
