EP2411167B1 - Punching tool, machine tool comprising such punching tool and method for checking the counterpart of an alignement ring with a punch - Google Patents

Description

The present invention relates to a punch with a punch and a punch associated adjustment ring which is placed on a punch shaft of the punch against an axial stop, a machine tool with such a punch, and a method for checking the affiliation of such Justierringns to such a punch ,

A punching tool has as essential components a punch and an adjusting ring, the latter being used to hold the punching tool in a tool holder of a machine tool, in particular a punching machine. Under a punching tool is understood in the sense of this application not only a punching tool in the classical sense, but a forming, embossing, forming, etc. tool that is suitable for punching and / or forming machining a workpiece.

There are different types of punches, which are adapted to the respective material processing (forming, stamping, etc.). Accordingly, there are also different types of Justierringen, which are adapted to different punch shaft designs of the punches and which are to adapt the punching tools to different machine mounts of machine tools. During assembly of the adjusting ring on the punch, the problem may arise that an unfavorable or incorrect combination of punch or punch shaft and adjusting ring is selected.

In general, two types of punches are used with different stamp shaft designs, namely those on the one hand, in which the axial stop is designed as a flat surface and on the other hand, those in which the axial stop is designed stepped, i. has at least one stage. For the first punch shaft design fits an adjusting ring with a flat bottom, the second an adjusting ring with a stepped bottom. The overall thickness of the Justierringe are usually the same size. If, for the production of the punching tool, an adjusting ring with a flat underside is combined with a punch with a stepped axial stop, the adjusting ring sits too high on the stamping shank. In this case, the punching tool typically does not fit into a punch holder of a machine holder on a machine tool and is therefore not functional.

This incorrect assembly can lead to a collision when replacing the punching tool by means of a tool changing device on a machine tool if the machine tool does not have a punch height monitoring. In the case of machine tools with stamp height monitoring, an incorrect error message results in an error message, however there is the control of the stamp height only in the machine tool, which at least a disruption of production and possibly a program demolition with subsequent re-entry and in the worst case, the rejection of the currently machined workpiece as a committee pulls. Also, the punching tool must be removed from the machine tool and pre-prepared, ie the adjusting ring must be replaced and aligned again.

In the DE 203 15 143 U1 a slotted adjusting ring is described for use in conjunction with a punch. At the punch a pin is fixedly mounted, which protrudes radially out of a cylindrical shaft of the punch out and which can be brought into engagement with a matching groove in the adjusting ring. Similar punching tools are from the DE 202 19 369 U1 and from the DE 102 55 219 B3 known.

From the DE 100 32 045 C2 a punching tool has become known, the punch in an adjusting ring can be fixed, with a wedge are provided as rotation in a tool holder and a rotation between the punch and the adjusting ring. The anti-rotation is there adjusted formierringseitig adjusting ring side of the wedge in the direction of rotation.

In the DE 10 2006 002 547 A1 is a punching tool, in particular for punching machines with tool changing devices, known, in which the punch and the adjusting ring are arranged in a defined angular position to each other. The punch and the adjusting ring each have corresponding receptacles into which an adjusting element is inserted or engages. The punching punch and the adjusting ring can be connected or connected by means of a locking seat. Eir similar punching tool is in the DE 20 2006 000 788 U1 described.

Object of the invention

It is an object of the present invention to provide a punching tool in which a reliable assembly of the adjusting ring can be ensured at the punching punch.

Subject of the invention

This object is achieved by a punching tool of the type mentioned, in which the axial stop has a step, wherein on the adjusting ring on its underside adapted to the stepped axial stop stage is provided, and wherein on the stamp shank at a distance from the axial stop, which corresponds to at least one axial thickness of the Justierrings and which is smaller than the sum of the thickness of the Justierrings and a step height of the step a mark is attached, which remains visible after placing the Justierrings against the axial stop.

To detect if a suitable alignment ring, i. a compatible with the punch adjusting ring is placed on the stamp shaft, a mark is attached to the stamp shaft. This marking is typically located approximately at a distance from the axial stop which corresponds to the axial thickness of the punch associated with, e.g. corresponds to this compatible adjustment ring. When attaching a non-compatible alignment ring, the mark is covered by the attached Justierring so that the wrong combination of Justierring and punch can be detected. It is understood that at least part of the marking should be spaced further from the axial stop than the thickness of the associated adjusting ring, so that it remains at least partially visible after attaching the matching adjusting ring.

Since the axial stop has a step, the correct combination between punch and adjusting ring is particularly important, since when placing a "wrong" Justierrings, e.g. with a flat bottom of the punches may not be set in the tool punch recording or collided with this.

The marking can be applied during the labeling process of the stamp, eg by laser inscription. If this happens parallel to the "geometry marking" on the upper part of the punch, it is even cost-neutral. There is also no technical risk, for example due to breakage of the punch shaft due to the notch effect of the laser, since the introduced notch has only a very small depth. It is understood that the notch also with the help of other manufacturing processes than by Laser marking can be attached to the stamp. The solution described above is fully compatible with all adjusting rings and punches in the field and can also be retrofitted. The marking can be dispensed with, in particular, also the remeasurement or estimation of the stamp height.

The distance of the marking from the axial stop should not be more than about 3 mm, preferably not more than about 1 mm larger than the thickness of the adjusting ring. This can ensure that the punch height is not too large, since the mark remains visible only if the thickness of the Justierrings deviates only slightly from the nominal thickness of the Justierrings. In particular, it can also be detected in this case whether a compatible adjusting ring has been pushed completely onto the punch.

During assembly, the correct combinatorics can thus be ensured by a simple optical control (marking visible? Yes / no). In addition, it is thus ensured that the adjusting ring is pushed to the axial stop, which is also favorable, since a properly selected adjusting ring, if it is not pushed open, also leads to the problem described above.

In one embodiment, the marking is formed by a circumferential ring on the stamp shaft. The circumferential marking ensures that it remains visible from all sides. In addition, the marking is limited in the axial direction to the width of the ring (typically 2 mm or less, preferably about 1 mm), so that even slight deviations from the predetermined axial thickness of the Justierrings can be detected.

In a not belonging to the invention punching tool of the type mentioned in each case a mark is attached to the punch and the associated adjusting ring, wherein the markings have at least one matching property. Matching punches and Justierringe can be identified by matching markings. The property of the markers is, for example, selected from the group comprising: shape of the mark and color of the mark. Matching Justierringe or punches can thus on the basis of matching geometry or matching color, etc. are recognized. In this case, typically an optical identification by an operator, but also a machine identification by means of optical sensors is possibly possible. The markings may in particular be designed such that they indicate a radial position on the punch or the adjusting ring, so that they can be brought into a correct angular position at which the two parts can be fixed subsequently eg by means of an adjusting element (see below). The markings or parts of the markings extend in this case only over a small angular range of, for example, less than 5 ° or less than 1 °. In particular, a tip may be formed on the markers for this purpose.

In one embodiment, the punch and the adjusting ring on corresponding receptacles for an adjusting element in order to arrange the punch and the adjusting ring in a defined angular position to each other. The adjusting element may be, for example, a centering pin, which is inserted into two aligned axial bores on the punch or the adjusting element, as in the cited above DE 10 2006 002 547 A1 is described. If the marking on the punch shaft is supplemented by a pin connection between punch and adjusting ring, the punch can be preassembled without any aids for alignment. The marking on the punch shaft ensures the correct selection and the correct height of the adjusting ring, the pin connection the exact angular position of the punch, for example with respect to a Justierkeils.

Another aspect of the invention is embodied in a machine tool for punching and / or forming a plate-like workpiece, preferably a sheet, comprising at least one punching tool as described above. Due to the reliable installation of the adjusting ring on the punch, an effective control of the punch height of the punching tool is made possible, so that operational failures due to an incorrect punch height can be avoided.

To check the affiliation of an adjusting ring to a punch, a method can be carried out, which comprises: placing the adjusting ring on the punch shaft until the adjusting ring with a formed on its underside, to a Staggered axial stop of the punch adapted stage abuts a stepped axial stop of the punch, and Checking whether after marking a mark on the punch or on the punch shaft remains visible, in a corresponding at least the axial thickness of the punch associated adjustment ring distance from the axial stop is mounted, which is smaller than the sum of the thickness of the Justierrings and a step height of a step of the stepped axial stop.

Further advantages of the invention will become apparent from the description and the drawings. Likewise, the features mentioned above and the features listed further can be used individually or in combination in any combination. The embodiments shown and described are not to be understood as exhaustive enumeration, but rather have exemplary character for the description of the invention.

Fig. 1

eine schematische Darstellung einer Ausführungsform einer erfindungsgemäßen Werkzeugmaschine,

Fign. 2a-c

eine schematische Darstellung eines Stanzstempels, eines Justierrings, sowie eines aus diesen Teilen zusammengebauten Stanzwerkzeugs mit einer Markierung am Stempelschaft, und

Fign. 3a-c

eine schematische Darstellung analog zu Fign. 2a-c, bei der bei einem nicht zur Erfindung gehörigen Stanzwerkzeug sowohl an dem Stempelschaft als auch an dem Justierring eine Markierung angebracht ist.

Show it:

Fig. 1

a schematic representation of an embodiment of a machine tool according to the invention,

FIGS. 2a-c

a schematic representation of a punch, an adjusting ring, as well as an assembled from these parts stamping tool with a mark on the stamp shaft, and

FIGS. 3a-c

a schematic representation analogous to FIGS. 2a-c in which a marking is applied to a stamping tool not belonging to the invention both on the stamping shank and on the adjusting ring.

Fig. 1 shows a machine tool 1 for cutting and / or forming plate-like workpieces in the form of a stamping / forming machine for processing sheets. The punching / forming machine 1 has a C-shaped machine frame 2 , in the throat area of which a workpiece support 3 formed as a workpiece support is arranged, which for the storage of a workpiece to be machined in Shape of a sheet 4 is used. On its upper side, the workpiece table 3 forms a horizontal support plane 5 for the sheet 4 to be processed, which is parallel to the x / y plane of the in Fig. 1 shown coordinate system runs. By means of a coordinate guide 6 , the clamping device 7 clamped sheet 4 in the support plane 5 of the workpiece table 3 is displaced.

At the front end of the upper leg of the C-shaped machine frame 2, a tool punch receptacle 8 is arranged, in which a punching tool 9 is mounted, which has a punch. Furthermore, a tool die receptacle 10 is provided at the front end of the lower leg of the C-shaped machine frame 2, in which a tool die 11 is mounted. The punching tool 9 and the tool die 11 together form one Tool unit 12 for separating and / or forming the sheet 4.

A drive unit of the punching / forming machine 1 is formed by a punch drive 13 and a die drive 14 in the form of linear drives. By means of the punch drive 13, the tool punch receptacle 8 together with the punching tool 9 mounted thereon or fixed along a lifting axis 15 relative to the workpiece table 3 can be raised and lowered. In a comparable manner, the tool die holder 10 together with the tool die 11 mounted or fixed therein can be raised and lowered by means of the die drive 14 along the lifting axis 15 with respect to the workpiece table 3. Furthermore, the tool punch receptacle 8 and the tool die receptacle 10 are rotationally adjustable by means of a rotary drive not shown in detail about an identical with the lifting axis 15 tool axis of rotation 16 .

At the coordinate guide 6, a linear magazine 17 is provided with further tool units 12. The tool units 12 located in the linear magazine 17 are each held by a tool cassette 18 and, depending on requirements, can be fixed to the tool punch receptacle 8 or the tool die receptacle 10 for machining the sheet 4.

During tool change and during workpiece machining, all drives of the stamping and forming machine 1 are controlled by means of a numerical control unit 21 . The numerical control unit 21 comprises, in particular, memory means 19 for storing tool data and control means 20 for detecting both the raising, lowering and rotating movements of the tool punch receptacle 8 and the raising, lowering and rotating movements of the tool die receptacle 10 based on FIGS stored data on the workpiece 4 and the tool 12 to measure and control.

FIGS. 2a c show an embodiment of the punching tool 9 of FIG Fig. 1 in detail. The punching tool 9 comprises a punch 9a and an adjusting ring 9b . The adjusting ring 9 b is placed on a punch shaft 22 of the punch 9 a against an axial stop 23 (paragraph), which is formed on the punch shaft 22 is and has a radially inner stage 23a . After placing against the axial stop 23 of the adjusting ring 9 b can be fixed to the punch shaft 22, for example by this by a in Fig. 2b shown, by a gap 24 in the adjusting ring 9b passing through locking screw 23 is fixed or clamped. A wedge on the adjusting ring 9b serves as anti-rotation of the punching tool 9 in a tool holder.

The adjusting ring 9b has a thickness D of, for example, 10 mm, which is adapted to the axial dimension of the punch 9a so that when mounted Justierring 9b, which has on its underside adapted to the stepped stop 23 stage 23a, one between the top the adjustment ring 9b and a radially circumferential groove 25 of the ram shaft 22 measured punch shaft height H is obtained, which corresponds to a height H ', which is formed on the tool punch holder 8 between a nose and a shoulder on which the adjusting ring 9b rests with its upper side , In the case of a punch punch 9a and jusiterring 9b that matches each other, it is thus ensured that the punch shaft 22 of the punch 9a can be inserted into the tool punch receptacle 8, since the head of the punch 9a does not collide with the nose on the tool punch receptacle 8. In the case of an incorrect combination of punch 9a and adjusting ring 9b, on the other hand, the punch shaft height H between the adjusting ring 9b and the groove 25 in the punch shaft 22 may deviate from the height H 'at the tool punch receptacle 8 and lead to a collision.

In order to detect such a faulty assembly of the punching tool 9, in which an adjusting ring 9b is placed on the punch 9a, which deviates from the correct, adapted to the height H 'of the tool punch holder 8 stamp shaft height H, is on the punch shaft 22 of the punch 9a a marker 26 mounted in the form of a circumferential ring. The marking 26 in this case has a distance A from the stop 23, which is slightly larger than the axial thickness D, which has the adjusting ring 9b along the punch shaft 22. In this case, the distance A may be, for example, not more than 5% or 2% greater than the axial thickness D of the adjusting ring 9b or in absolute value not more than 1 mm greater than the axial thickness D of the adjusting ring 9b. The exact value depends on the height of the step 23a on the axial abutment 23, since the distance A is only so great may be chosen that the mark 26 by a "wrong" Justierring, ie an adjusting ring, the underside of which is not adapted to the stepped system 23 (for example, an adjusting ring with a flat bottom), is covered. The distance A will thus generally not exceed the sum of the thickness D of the adjusting ring 9b and the step height S of the step 23a.

The marker 26 may be attached to the punch shaft 22, e.g. be applied by laser writing. It is understood that the marking 26 does not necessarily have to be executed as a continuous, straight line, but that this can also be executed, if necessary, dashed, jagged, etc. The axial thickness of the marking should, however, generally not exceed about 1 mm, so that a reliable detection of the matching to the punch 9a with the stepped system 23 Justierrings 9b can be ensured.

In any case, the marking is designed so that it remains at least partially visible after placement of the adjusting ring 9b and thus ensures recognition of the correct combination of punch 9a and adjusting ring 9b. It can also be recognized whether a compatible adjusting ring 9b is completely pushed onto the punch 9a.

The punch 9a and the adjusting ring 9b each have an axial bore 27 , 28 which are aligned in the correct angular position. By means of a (not shown) centering pin which engages in the aligned bores 27, 28, the punch 9a and adjusting ring 9b can be fixed in the correct angular position.

In the manner described above, the punching tool 9 can be preassembled without alignment aid, since the marker 26 ensures the correct selection and the correct height of the adjusting ring 9b and the pin connection ensures the exact angular position of the punch 9a for adjusting ring 9b.

The correct combination of punches and adjusting ring can also be determined with the aid of a further embodiment of a punching tool 9 ' , as shown in FIG FIGS. 3a -c is shown. There, both the punch 9a ' and the adjusting ring 9b' (with thickness D) each have a mark 29 , 30 in the form of a triangle. By the Matching shape of the markers 29, 30, the affiliation or compatibility of the adjusting ring 9b 'to the punch 9a' can be recognized. It is understood that additionally or alternatively, there may also be a match in the color or other characteristics of the markings 29, 30 that makes it possible to identify associated pairs of punches and alignment rings that can be assembled into a punching tool.

At the in Fig. 3a shown embodiment of the punch 9a 'with a plane axial abutment surface 23, the problem of deviation of the stamp shaft height H from the predetermined by the tool punch receptacle 8 height H' usually does not occur, since both the in Fig. 3b shown adjusting ring 9b ', which has a flat bottom, as well as in Fig. 2a shown adjusting ring 9b, on the underside of a stepped axial bearing 23 of Fig. 2a matching recess is provided on the punch 9a 'of Fig. 3a can be placed and in this case the maximum punch height is not exceeded, since in both cases, the top of the Justierringe 9b, 9b 'have the same distance D from the contact surface 23.

The markings 29, 30 can furthermore also be used to align the punching punch 9a 'and the adjusting ring 9b' in a defined angular position, in particular if the markings 29, 30, as in FIG FIGS. 3a-c shown each having a tip on which the markings 29, 30 can be aligned. In this case, if necessary, the receptacles for fixing the correct angular position can also be dispensed with and the adjusting ring 9b 'fixed when the markings 29, 30 are aligned with one another.

In summary, in the manner described above, the Vorrüstvorgang be simplified by a simple optical control / review of the "assembly state" of the punch and the faulty assembly (incorrect combination and incorrect clamping position) of punch and Justierring a punching tool can be avoided. The optical control requires no knowledge of the operator about the punching technique. Due to the more process-oriented assembly, production stoppages, machine stoppages, collisions, etc. are avoided when using the punching tool in a machine tool.

Claims (6)

1. Punching tool (9, 9') comprising:

   a punching stamp (9a, 9a') and

   an adjustment ring (9b, 9b') which is associated with the punching stamp (9a, 9a') and which can be placed on a stamp shaft (22) of the punching stamp (9a, 9a') against an axial stop (23, 23'),

   characterised in that

   the axial stop (23) has a step (23a), wherein a step (23a), which is adapted to the stepped axial stop (23), is provided on the lower side of the adjustment ring (9b), and wherein there is applied to the stamp shaft (22), with a spacing (A) from the axial stop (23, 23') which corresponds at least to an axial thickness (D) of the adjustment ring (9b) and is smaller than the sum of the thickness (D) of the adjustment ring (9b) and a step height (S) of the step (23), a mark (26) which remains visible after the adjustment ring (9b) has been placed against the axial stop (23).
2. Punching tool according to claim 1, wherein the spacing (A) of the mark (26) from the axial stop (23) is no more than 3 mm, preferably no more than 1 mm, greater than the axial thickness (D) of the adjustment ring (9b, 9b').
3. Punching tool according to claim 1 or claim 2, wherein the mark (26) is formed by a continuous ring on the stamp shaft (22).
4. Punching tool according to any one of the preceding claims, wherein the punching stamp (9a, 9a') and the adjustment ring (9b, 9b') have corresponding receiving members (27, 28) for an adjustment element in order to arrange the punching stamp (9a, 9a') and the adjustment ring (9b, 9b') in a defined angular position relative to each other.
5. Machine tool (1) for the punching and/or shaping processing operation of a plate-like workpiece (4), preferably a metal sheet, comprising at least one punching tool (9, 9') according to any one of the preceding claims.
6. Method for verifying the association of an adjustment ring (9b) with a punching stamp (9a), comprising:

   placing the adjustment ring (9b) on a stamp shaft (22) until a step (23a), which is adapted to a stepped axial stop (23) of the punching stamp (9a) and is formed on the lower side of the adjustment ring (9b), abuts on a stepped axial stop of the punching stamp (9a), and

   verifying whether after the positioning a mark (26) remains visible on the punching stamp (9b) which is applied with a spacing (A) from the axial stop (23) that corresponds at least to the axial thickness (D) of an adjustment ring (9b) which is associated with the punching stamp (9b) and is smaller than the sum of the thickness (D) of the adjustment ring (9b) and a step height (S) of a step (23a) of the stepped axial stop (23).

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