The invention relates to a tool and to a method for processing plate-like or plate-shaped 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 processes plate-shaped 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.
Japanese published patent application JP 2000-153 321 A1 furthermore discloses a tool for processing plate-like workpieces. An upper tool comprises a processing tool with an obliquely running cutting edge. The lower tool comprises an opening, wherein a counterpart cutting edge offset downwardly relative to a bearing surface is provided in the opening. During a working stroke of the upper tool relative to the lower tool, a cutting process firstly occurs at the leading cutting edge of the processing tool. A tab is cut out and bent and, during a further cutting stroke, is cut off at the cutting edge that lies in the opening of the lower tool. Bending and punching take place in one stroke, wherein the processed workpiece remains on the plate-like workpiece.
International patent application publication WO 2011/148393 A1 and its counterpart US 2013/0061728 A1 disclose a punching and bending tool in the case of which, in a working stroke during which the upper tool is moved toward the lower tool, the plate-like material is firstly punched out and, during the further punching processing operation, simultaneous bending of the workpiece occurs.
It is accordingly an object of the invention to provide a tool and a processing method which overcome a variety of disadvantages of the heretofore-known devices and methods of this general type and which provides for the processing of plate-like workpieces with increased flexibility.
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 comprising:
an upper tool and a lower tool movably disposed toward one another for processing a workpiece arranged in between the upper and lower tools;
the upper tool having a clamping shank and a main body, arranged on a common position axis, and a processing tool mounted to the main body opposite the clamping shank;
the lower tool having a main body with a bearing surface for the workpiece and an opening formed within the bearing surface;
the processing tool of the upper tool being formed with at least one bending edge and at least one cutting edge; and
the main body of the lower tool being formed with at least one counterpart bending edge and at least one counterpart cutting edge.
In other words, the objects or the invention are achieved by means of a tool for processing plate-like workpieces, in the case of which a processing tool of the upper tool comprises at least one bending edge and at least one cutting edge, and the main body of the lower tool has at least one counterpart bending edge and at least one counterpart cutting edge. In this way, for example in a first processing step, a workpiece part, preferably in the form of a tab-like cut-out portion, can be processed by way of a bending stroke, wherein the degree of angular bending can be influenced in a manner dependent on the stroke movement between the upper tool and the lower tool. By means of one or more successive stroke movements, one or more angled bends can be introduced into the workpiece part. The same tool as that used for producing the angled bend or bend can be used for cutting off the workpiece part from the plate-like material. Here, the cutting edge of the upper tool and the counterpart cutting edge of the lower tool are aligned with one another, and the plate-like material is transferred into the cutting position, such that the workpiece part is subsequently cut from the plate-like workpiece by way of a cutting stroke. Here, the cut-off workpiece part may be a good part or a waste part. By means of this tool, a bending and punching processing operation can be made possible without a tool change simply by adjusting the position axes of the upper tool and lower tool and the assignment of the position axes of the upper tool and of the lower tool to one another.
The cutting edge and the bending edge are preferably formed separately from one another on the processing tool, preferably on the same processing tool. A relatively great bending width and limb width are thus obtained.
Furthermore, the cutting edge and the bending edge on the processing tool of the upper tool preferably run parallel to one another and are oriented perpendicular to the positioning axis. This allows straightforward implementation of individual positions of the upper tool relative to the lower tool for a bending and also a punching or cutting process.
The cutting edge and the bending edge on the processing tool of the upper tool preferably lie in the same plane and are configured so as to be perpendicular to the position axis. This also allows straightforward production of such a processing tool.
The cutting edge and the bending edge advantageously delimit a ram surface on the processing tool, which ram surface is preferably oriented perpendicular to the position axis. Support can thus be provided during the bending and punching processing operation.
Furthermore, the bending edge may be configured so as to run perpendicular to the position axis, and the cutting edge may be oriented so as to be inclined at an angle relative to the position axis. In this way, a cutting process can be implemented in which a workpiece part is completely cut from the plate-like material only with increasing plunging depth.
One advantageous configuration of the bending edge on the processing tool provides for an inclined surface to extend in the direction of the main body proceeding from the bending edge, which inclined surface is inclined toward the position axis. The inclined surface is preferably oriented at an angle of less than 90° with respect to the ram surface of the processing tool. A bending edge with an undercut can be formed in this way. The bending edge allows overbending after the workpiece part has been bent at an angle of 90°, for example in order to compensate for a spring-back effect, such that a 90° angled bend is attained after the spring-back effect that has occurred.
One advantageous embodiment of the tool provides for the bending edge and the cutting edge on the upper tool to be aligned within a projection area which is formed perpendicular to the position axis and, as viewed in the stroke direction, by the main body. Alternatively, provision may be made for at least the bending edge or the cutting edge of the upper tool to lie outside the projection area which is formed perpendicular to the position axis and, as viewed in the stroke direction, by the main body. In the first embodiment, the height of the portion bent at an angle is determined by the spacing of the bending edge to the main body. In the second alternative embodiment, the height of the portion bent at an angle may be greater than the spacing between the bending edge and the main body, if the bending edge lies outside the projection area.
On the main body of the upper tool, there are preferably provided hold-down elements, between which the processing tool extends and relative to which the processing tool can be led out. The hold-down elements preferably extend, in terms of height, as far as the cutting and bending edge of the processing tool. Alternatively, the at least one hold-down element may extend beyond the bending edge and the cutting edge of the processing tool. In this way, the bending and cutting edges are set back in relation to an end surface of the hold-down elements. The length of the at least one hold-down element may extend at least partially along the cutting and/or bending edge. Preferably, the at least one hold-down element extends approximately or entirely along the length of the bending and/or cutting edge. The hold-down elements are preferably of elastically flexible form. The hold-down elements serve for securely positioning the plate-like workpiece on the bearing surface of the lower tool as the bending edge and counterpart bending edge are moved toward one another and at least partially moved past one another. An analogous situation applies, in the case of the cutting stroke, to the cutting edge and counterpart cutting edge of the upper tool and lower tool.
A further advantageous configuration of the tool provides for the counterpart bending edge and/or the counterpart cutting edge to be provided fixedly at the opening of the bearing surface of the main body of the lower tool. This allows a simple structural design. Alternatively, provision may be made for the counterpart bending edge and/or the counterpart cutting edge to be provided fixedly on the base body of the lower tool, wherein the opening of the bearing surface is positioned so as to adjoin and/or so as to be flush with the counterpart bending edge and/or counterpart cutting edge and is displaceable relative to the base body.
The at least one counterpart bending edge and/or the at least one counterpart cutting edge are provided in the opening of the bearing surface of the main body of the lower tool and/or so as to adjoin the bearing surface of the main body. If, for example, only relatively small workpieces are produced, it is advantageous if the at least one counterpart bending edge and the at least one counterpart cutting edge are provided in the opening of the bearing surface. In this way, the displacement movements between the upper tool and lower tool can be kept small. Workpiece parts that have been cut off can be discharged downwardly through the opening in the lower tool. If relatively large or relatively wide plate-like workpieces are to be processed, the counterpart bending edge and/or the counterpart cutting edge may be provided outside the bearing surface but so as to adjoin the latter in order to perform the processing operation. After a cutting stroke, the processed workpiece parts may be discharged via a discharge flap in a workpiece bearer of the machine tool.
With the above and other objects in view there is also provided, in accordance with the invention, a method for processing plate-like workpieces, in which method a tool according to any one of the embodiments described above is used, and a workpiece part of the plate-like workpiece, which may be in the form of a tab-like cut-out portion, is positioned relative to the bearing surface of the lower tool, and the bending edge on the upper tool and the counterpart bending edge on the lower tool are aligned with one another, and at least one bending stroke movement is effected during which the workpiece part is angled relative to the plate-like workpiece and during which the angled workpiece part and/or the cutting edge of the upper tool and the counterpart cutting edge of the lower tool are transferred into a cutting position in order to subsequently perform a cutting stroke by means of which the workpiece part is cut off. A rapid process sequence can thus be performed when bending and cutting a workpiece part to form the plate-like workpiece. Non-productive time for the changeover of the tool from a bending tool to a punching tool can thus be omitted. Owing to the reduced positioning of the deformed sheet-metal panel, the risk of scratches on the component and the jamming of the part are thus furthermore reduced.
Furthermore, it is preferable if the alignment of the bending edge or cutting edge of the upper tool with the counterpart bending edge or counterpart cutting edge of the lower tool is effected by means of a rotational movement and/or by means of a displacement direction along the upper and/or lower positioning axis. In particular, a displacement movement of the upper tool and/or lower tool in a Y direction is effected. A fast advancing movement and alignment of the upper tool and of the lower tool for the subsequent processing operation are thus possible.
A further advantageous configuration of the method provides that, during a bending stroke movement between the upper tool and the lower tool, a stroke movement along the stroke axes of the upper and lower tool is performed, or that a stroke movement that lies outside the stroke axis of the upper and lower tool is additionally superposed on the stroke movement along the stroke axes. The quality of the bending edge on the workpiece with regard to a visual appearance on the workpiece and overbending can be influenced in a manner dependent on the displacement movement.
In the case of a workpiece part for processing whose width is smaller than the opening in the bearing surface of the lower tool, a cutting position between the upper and lower tool is set such that a cutting edge of the upper tool is aligned with a counterpart cutting edge at the opening of the lower tool. In this way, after the cutting operation, a straightforward discharge downward through the lower tool is possible.
If the workpiece part for processing has a width that is larger than the opening in the bearing surface of the lower tool, a cutting position is set in the case of which the at least one cutting edge of the upper tool is aligned with a counterpart cutting edge on the lower tool, which counterpart cutting edge is provided outside the bearing surface. In this way, even relatively large workpieces can be processed using the same tool, which allows both bending and punching.
Provision is furthermore made whereby the cutting edge of the upper tool and the counterpart cutting edge of the lower tool are, for a cutting stroke, aligned with one another in a manner dependent on the respective material thickness of the workpiece part. This makes it possible for different material thicknesses to be processed in the same way using one and the same tool, and for a respective adjustment to be made possible in order to perform an optimum cutting stroke.
Provision is furthermore made whereby the bending edge of the upper tool and the counterpart bending edge of the lower tool are, for a bending stroke movement, aligned with one another in a manner dependent on the respective material thickness of the workpiece part. High bending quality can thus be achieved. Additionally, a wide variety of thicknesses of the workpiece parts can be processed in the same way using the same tool.
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, 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.
Referring now to the figures of the drawing in detail and first, in particular, to
The machine tool 1 serves for the processing of plates, referred to as 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 of 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 a 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 25, be moved along the positioning axis 16 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 a lower horizontal frame member 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.
In the main body 41, the lower tool 9 has an opening 46, which is preferably delimited by an encircling bearing surface 47. The opening 46 preferably extends all the way through the main body 41, such that workpiece parts 81 that have been punched out or cut away can be discharged through the opening.
The processing tool 37 on the upper tool 11 comprises at least one cutting edge 38 and at least one bending edge 45. At the end side, the processing tool 37 has a ram surface 43. The ram surface 43 is delimited in one direction by the cutting edge 38 and in an opposite direction by a bending edge 45. The cutting edge 38 and the bending edge 45 are preferably oriented parallel to one another. The cutting edge 38 and bending edge 45 preferably lie in a common plane at right angles with respect to the positioning axis 35. The ram surface 43 delimits the body of the processing tool 37 with an elongate rectangular geometry.
The bending edge 45 is adjoined at one side by the ram surface 43 and at the other side by an inclined surface 49. The inclined surface 49 is configured so as to be at an angle of less than 90° with respect to the ram surface 43. A bend radius 45 of the bending edge may be selected in accordance with the bend radii to be produced.
The lower tool 9, which for example comprises the opening 46, has an internally situated counterpart cutting edge 51 adjoining the bearing surface 47. The opening 46 is preferably of square or rectangular form. At least one further side edge of the opening 46 may be configured as a counterpart bending edge 52. It is preferable for one counterpart cutting edge 51 and two or more counterpart bending edges 52 to be provided, wherein the further counterpart bending edges 52 may in each case have different radii than one another. Aside from a square or rectangular opening, use may also be made of an opening in the shape of a polygon in order to be able to use further counterpart cutting or counterpart bending edges. Increased flexibility of the tool 31 can thus be realized. One or more further counterpart cutting edges may also be provided, which can be used if a first counterpart cutting edge has become unusable for example as a result of wear.
A punching-out surface 56 is provided so as to adjoin the internally situated counterpart cutting edge 51, which punching-out surface is configured so as to be parallel to the longitudinal axis 40 of the tool body 39, or so as to be inclined slightly relative to the longitudinal axis, in order to allow the workpiece part 81 to be cut from the workpiece 10 with high cut quality.
A hold-down element 71 is provided in each case laterally adjacent to the processing tool 39. The hold-down element 71 is preferably provided exchangeably on the main body 33 of the upper tool 11. The hold-down elements 71 are elastically flexible. Thermoplastic elastomers, in particular PU, are preferably used for forming the hold-down elements 71. Further resiliently elastic materials, in particular resiliently elastic materials which are suitable for the processing of plate-like material even with the use of lubricants or oils, may be provided. The hold-down elements 71 preferably have an end surface 72. The end surface 72 is preferably oriented parallel to the ram surface 43. The lateral spacing of the hold-down elements 71 to the processing tool 37 is dimensioned such that, when the hold-down elements 71 lie on the lower tool 9, a compression of the hold-down elements 71 is made possible, wherein a plunging depth of the processing tool 37 can still be effected such that the processing tool 37, in particular the bending edge 45, can also be adjusted relative to the counterpart bending edge 52 on the lower tool 9 so as to generate overbending on the workpiece part 81.
In some usage situations, the length of the hold-down element 71 is equal to the length of the processing tool 37.
In a first working step, the upper tool 11 is moved along the stroke axis 14 or the position axis 35 toward the lower tool 9. The ram surface 43 lies on the workpiece part 81. At the same time, the end surfaces 72 of the hold-down element 71 lie on the workpiece part 81 and/or on the workpiece 10 and fix this relative to the bearing surface 47 of the lower tool 9 (
During a stroke movement as per
If the workpiece part 81 is intended to exhibit overbending in relation to the workpiece 10, that is to say if it is the intention to initially set a bend angle of greater than 90°, a lateral displacement movement, in particular in a Y direction, is additionally superposed on the stroke movement of the upper tool 10. It is also possible for a displacement movement of the lower tool 9 along the lower positioning axis 25 to be effected exclusively or in addition. By means of the inclined surface 49 on the processing tool 37, the bending edge 45 can engage behind the counterpart bending edge 52, and the overbending can thus be achieved. This may be performed to such a degree that, after the processing tool 37 is moved out of the opening 46 of the lower tool 9, the angled bend 62 springs back to an angle of 90°.
Subsequently, for example, a cutting stroke is effected, which is illustrated in
The lower tool 9 as per
The bearing surface 47 is received on the main body 41 so as to be displaceable counter to the Z direction relative to the counterpart bending edge 52 and counterpart cutting edge 51. The opening 46 is provided in the bearing surface 47, which opening surrounds the ram surface 54. Elastically flexible restoring elements 55 are preferably provided between the bearing surface 47 and the main body 41. After an exertion of load on the bearing surface 47 as a result of a displacement movement toward the main body 41, the bearing surface 42 can be transferred back into the initial position, as illustrated in FIG. 13. It is advantageously possible for guide elements 57 to be provided, by means of which the bearing surface 47 is guided so as to be movable up and down relative to the main body 41. For example, only one guide element is illustrated, wherein it is preferable for several to be provided in a manner distributed uniformly over the circumference.
The upper tool 11 is positioned in an initial position relative to the lower tool 9 before the start of a pivoting and bending movement. This pivoting and bending movement may be performed analogously to that described with regard to
The tool 31 as per
In this embodiment, provision is made for at least the bending edge 45 to lie outside a projection area which is formed perpendicular to the position axis 35 and, as viewed in the stroke direction, by the main body 33. The cutting edge 38 may lie within or outside the projection area. In this embodiment, provision is made for the cutting edge 38 to be assigned a hold-down element 71. The bending edge 45 is provided without the assignment of a hold-down element 71. An end surface 72 of the hold-down element 71 preferably lies in the plane of the ram surface 43. This end surface 72 of the hold-down element 71 may also project slightly in the stroke direction relative to the ram surface 43. The hold-down element 71 is also of elastically flexible form. Further possible configurations of the hold-down element 71 that have been specified with regard to the embodiments described above also apply to this tool 31 as per
The lower tool 9 as per
Number | Date | Country | Kind |
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10 2019 119 849.6 | Jul 2019 | DE | national |
This application is a continuation, under 35 U.S.C. § 120, of copending International Patent Application PCT/EP2020/070473, 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 119 849.6, filed Jul. 23, 2019; the prior applications are herewith incorporated by reference in their entirety.
Number | Date | Country | |
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Parent | PCT/EP2020/070473 | Jul 2020 | US |
Child | 17582187 | US |