EP1554068A1

EP1554068A1 - Stripping device

Info

Publication number: EP1554068A1
Application number: EP03771104A
Authority: EP
Inventors: Harald Weigelt
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-07-25
Filing date: 2003-07-25
Publication date: 2005-07-20
Anticipated expiration: 2023-07-25
Also published as: BR0312895B1; AU2003253328A1; CA2493763C; MXPA05000993A; CA2493763A1; ATE356678T1; DE50306807D1; US8225702B2; KR20050026516A; CN1684780A; US20060071062A1; WO2004011172A1; EP1554068B1; CN100364687C; JP2006502002A; ZA200500652B; PT1554068E; BR0312895A; US20130036888A1; EP1384535A1

Abstract

The stripper device has fastener part (4) for fixing to the punch, and an elastic element (21). A stripper element (15) surrounding the punch is in contact with the work piece, e.g. the metal plate, and is enclosed by a guide element (11). The elastic element is positioned outside the work piece contact area, between stripper element or guide element and punch and/or within the guide element. The guide element is a sleeve, an the stripper element has a mainly straight shaft (17) and a projecting collar (18). Part of the shaft is coated with lubricant. The stripper element is of bronze or a similar material, and the elastic element is of a spring-elastic flexible or self-restoring material.

Description

stripping

The invention relates to a scraper device for use with a cutting tool with a cutting element, in particular a punch, for machining a workpiece, in particular a bent sheet metal, wherein at least one fastening piece for fastening to the cutting tool, a resilient element arranged outside the workpiece contact area wiping element coming into contact with the workpiece and surrounding the cutting element and at least one guide element guiding the wiping element are provided.

Scraper devices are known in connection with various types of cutting tools (DE 19605113 AI, DE 4035938 AI, DE 4235972 AI and WO 99/67038 AI). Such a stripping device is required in order, in particular in the case of punches or other cutting elements, to enable the machined workpiece, in particular sheet metal, to be stripped from the cutting element, in particular punches. During the cutting process, in particular the punching process, a front surface of the scraper lies against the surface of the workpiece, deflects somewhat during the penetration of the workpiece through the punch and when the cutting tool is withdrawn from the workpiece, so that the e.g. Punch is ensured from the workpiece.

Various wiper models are available on the market. Most have a mounting plate, by means of which they can be attached to the cutting tool, in particular a punch mounting plate. The wiper body consists, for example, as a rubber spring made of a hard plastic, the front surface of which is designed according to the workpiece contour. The shaping can be done by Cropping done. The rubber spring surrounds the punch on all sides. The. In most cases, the shape of the front surface of the scraper is not symmetrical, since the workpiece to be machined usually has an irregular shape.

From US 2,168,377 a wiper device for use with a punch for processing a flat flat sheet is known, in which an outer element is fastened to a specially designed holding plate of a cutting tool by means of screws and bolts. The inside of the outer element is provided with a longitudinal opening into which a stripping element and the punch are inserted. A resilient element in the form of a helical spring is inserted between the stripping element, the outer element and the punch. The stripping element has a substantially straight section and a projecting section, which can be supported on a projection within the longitudinal opening of the outer element or is held on to it, in order not to be inadvertently pushed out of the element.

US 1,723,935 discloses a structure of a stripping device similar to that of the above publication. Just like this, US 1,723,935 also uses a helical spring which is arranged within an outer guide sleeve between the punch, the stripping element and a special fastening device for fastening to the cutting tool. The outer guide sleeve is screwed onto a fastening piece, which is fastened to a further fastening piece, which is connected via a flange to the cutting tool via a screw connection.

US 4,993,295 discloses a stripping device for use with a punch for machining a flat sheet, in which, as in US 1,723,935, guide surfaces between an outer guide sleeve and a stripping element are relatively short, so that the stripping element can tilt within the guide sleeve under higher loads. Various disc springs are provided as a spring-elastic element, which are stacked on top of one another within the guide sleeve in such a way that curved surfaces face each other. A punch is located within the resilient element.

The scraper fer also has the task of keeping the workpiece in the desired shape during the machining process. This is particularly important when punching is to be carried out in the area of sheet metal edges, since it is easy there due to the punching process

Deformations can occur. However, the scraper should not independently deform the workpiece, but should only hold it in the desired prefabricated form. If a rubber spring scraper completely surrounding a punch is provided with an irregular front shape facing the sheet metal, this proves to be problematic if the scraper becomes clear after a few

Punching processes twisted around the punch. The surface shape of the scraper then does not match the surface shape of the sheet to be punched, which is why it does so in this case

Quality problems and complaints can come up.

DE 812498 discloses a stripping device for a punch with a helical spring which is arranged between a stripper plate and a punch head. The coil spring surrounds the area of the punch. There are three strips that are attached between the stamp head and stripper plate and maintain a distance between these two elements. The attachment is made using screws and elongated holes so that the distance between the scraper plate and the punch can be adjusted is possible. On the other hand, twisting the scraper plate is hardly possible due to the strips.

FR 1456310 discloses a stripping device which in one embodiment comprises a coil spring and in another an elastic element which is inserted between two fixed plates. In the case of the second embodiment, a screw bolt is arranged between the two fixed plates, similarly as is provided by the strips in DE 812498 for the stable connection of the two plates. The bolts can also prevent the plates from twisting against each other.

However, these publications do not disclose any possibility of adaptation to the special shape of deformed sheets. Only straight sheets are always punched in all publications. Especially in the automotive industry, however, it is necessary to provide wiping devices that adapt to the special shapes of deformed sheets or can be adapted to them without problems, essentially leave no traces on the punched sheets and have a long service life, that is, so stable are designed to withstand a large number of strokes, especially maintenance-free more than 1 million strokes. The stripping device should also be designed so that a simple and quick change and exchange of stripping devices can be made. This is not possible with the devices of the prior art, which are complicatedly attached to the cutting tool.

To prevent twisting, a spring-loaded steel wiper is also known from Dayton Progress GmbH. An anti-rotation device for the punch is formed in that the punch is in one

Partial area is constricted in cross section and flattened rectangular. A portion of the scraper engages in this area and is attached to the steel scraper by means of screws.

This solution proves to be disadvantageous due to its susceptibility to failure due to limited stability in the area of the small fastening screws and the risk of breakage of the constricted stamp. Since the individual parts of a scraper have to match each other exactly and often a complicated assembly is required, the hand-made alternatives result in average prices of EUR 1,800 per piece. In comparison, the pure rubber wipers, as described above, cost about 100 EUR each. However, these have the disadvantage that only small quantities are possible for use when punching a sheet from the inside, with only certain shapes in addition to the disadvantages already mentioned above. The steel scraper also has the disadvantage that the screws holding the engaging section on the steel scraper are very small and often cannot withstand the forces that occur, especially since they are loaded transversely. The durability of a rubber scraper, as described above, is approx. 80,000 strokes, after which it is no longer possible to ensure that it is properly wiped off and thus the process reliability of a production is impaired.

The present invention is therefore based on the object of providing an improved scraper device which is stable, in particular in which an anti-rotation device in the range of a hundredth of a millimeter is possible and one-sided thrust forces can be eliminated. In addition, high stroke rates of in particular more than 1 million strokes, in particular the durability and stability compared to the stripping devices of the prior art, should be possible, especially for use in the automotive industry. The stripping device should also be relatively inexpensive and as small as possible. This object is achieved with a stripping device according to the preamble of claim 1 in that a device for securing against rotation is provided for essentially preventing the stripping element from rotating. Further developments of the invention are defined in the dependent claims.

This creates a stripping device for use with a cutting tool with a cutting element, in particular a punch, in which a long durability of the resilient element is made possible because it does not come into contact with the workpiece. In addition, it is preferably loaded centrically and without any oments, which also prevents uneven wear or stress. This enables the spring-elastic element to last for more than 1 million strokes. Due to the use of a manageable number of individual parts which, when inserted into one another, result in the stripping device, it is more robust than the stripping devices of the prior art. Due to the use of a guide element, preferably of guide sleeves or guide bushes, a reproducible movement of the stripping device relative to the cutting tool or the cutting element, in particular a punch, is also advantageously possible. In addition, guiding through columns is no longer necessary, as is required with numerous wipers of the prior art, in order to enable a firm attachment in the cutting tool. Such columns are intended, in particular, to absorb transverse forces which occur during the cutting process and which can twist or shift the scraper. In addition, a more cost-effective solution is created than, for example, in the case of the conventional manually built steel scrapers of the prior art. This is made possible in particular by the fact that the manufacturing effort is very much less than with these products. Arranging the resilient element outside the workpiece contact area has various advantages. As a result, the resilient element does not constantly come into contact with oils and greases, which gradually attack and destroy it. In addition, the contact of the workpiece with the stripping element instead of the spring-elastic element creates an essentially rigid contact surface, which enables the workpiece to be kept in shape and, conversely, is not deformed by the workpiece. The stripping element is therefore particularly preferably made of bronze or another material which can be adapted to the workpiece surface shape and which is strong enough not to be deformed by the workpiece during the machining process. Preferably, such a material is chosen with which it is possible to individually shape the stripping element with respect to its front surface shape in order to adapt it to the workpiece to be cut. The resilient element is preferably a rubber spring or preferably consists of another resilient, restoring and / or resilient material. When using a rubber spring, fatigue fracture, for example of a coil spring, can be avoided.

The device for securing against rotation preferably comprises a stripping element with an irregular cross-section and / or an elongated hole or polygonal hole in the guide element. It proves to be particularly advantageous if the device for securing against rotation has a pair of wiping element and hole or opening in the guide element that is asymmetrically formed at least in one orientation to ensure unambiguously oriented installation of the wiping element, in particular an elongated hole with three straight and one curved side and a correspondingly designed stripping element. By providing a stripping element which is irregularly or at least partially asymmetrically shaped in cross-section and in particular a cross-section of the opening in the opening which is adapted to it Guide element in which the stripping element is guided essentially prevents twisting and incorrectly oriented installation of the stripping element in the guide element. Providing an elongated hole or polygonal hole and / or a scraper element which is irregularly shaped in cross section prescribes a clear position during installation, so that the scraper element formed on its front surface in accordance with the workpiece contour cannot be inadvertently rotated in its position even when changing quickly. In addition, faster assembly is possible because the exact position of the stripping element does not have to be determined first, but rather through the shape of the stripping element and the opening in the guide element, preferably the guide sleeve or guide bush, and the preferred provision of inner and outer guide surfaces on the Scraper element is specified. A faster, easier and more precise assembly of the stripping device on the cutting tool is thus possible than is possible with the stripping devices of the prior art. In addition to the quick and easy installation and replacement of a wiping element and the correct orientation, this also prevents damage to the workpiece to be punched. Even complex-shaped sheets can thus be processed essentially without damage, in particular also due to the advantageous possibility of adapting the front surface of the stripping element to the shape of the workpiece, in particular sheet metal, as a result of which markings of the workpiece around the punched hole can be avoided. With the stripping devices of the prior art, such markings cannot be avoided regularly, since the front surface shape of the stripping element is not adapted to the shape of the (punched) workpiece (shaped sheet) to be machined. For example, holes are to be provided in the lower region of vehicle doors according to their three-dimensional shape, the punching of which is not possible with the above-described prior art devices without damaging the door profile, since neither there Protection against rotation is also provided, an adaptation of the shape of the front surface area of the stripping element to that of the door profile is provided.

The resilient element is preferably arranged between the stripping element or guide element and cutting tool and / or within the guide element. This avoids contact of the resilient element with the workpiece. In addition, the resilient element is held firmly in the stripping device. This enables a uniform load that keeps the wear of the spring-elastic element as low as possible. In addition, a defined position of the resilient element is determined, and it can also be replaced at any time if it is worn.

Preferably, the stripping element and the spring-elastic element surrounding the cutting element are oriented such that they can be loaded essentially without torque and in particular centrally. This advantageously prevents uneven wear and tilting of the resilient element and the stripping element. In addition, a reproducible position of the resilient element is specified, in particular in the case of replacement, so that an exchange can take place quickly and without problems.

At least one guide sleeve is preferred as a guide element outside the stripping element; this is arranged at least partially in a leading manner and / or at least one guide bush is arranged as a guide element within the wiping element in a guiding manner. By providing a guide element, a guiding of the stripping element is created, which enables a defined movement of the stripping element along the cutting element, in particular a punch. In addition, the stripping element has on its inside facing an inserted cutting element, in particular to its shaft, preferably at least one guide surface. As a result, the stripping element can also be guided along the cutting element, in particular along its shaft. An internal and external guidance of the stripping element is thus possible. Tilting, as occurs in particular in the case of rubber springs of the prior art, no longer has to be feared. Rather, the exact movement is retained even after more than 1,000,000 strokes.

The stripping element preferably has a substantially straight section and a projecting section, guide surfaces being provided on the straight and the projecting section of the stripping section. At least one guide surface is preferably provided between the stripping element and the guide element, the length of which can be selected as a function of the forces acting on the stripping device, in particular thrust and lateral forces, in order to ensure tilt-free guidance. The provision of a straight and a cantilevered part of the stripping element provides an even better protection against tilting relative to the cutting element and the guide element, since two guide surfaces are provided, which are in particular arranged at a distance from one another. The respective length of the guide surface or guide surfaces can be selected depending on the forces acting on the stripping device. In this case, a longer guide surface is preferably selected if the forces that occur are higher.

To improve the sliding of the wiping element within the guide element, a lubricant, in particular a lubricant suitable for maintenance-free lubrication, in particular a solid lubricant, is preferably provided at least in a partial region of the straight part of the wiping element. The use of a solid lubricant proves to be particularly advantageous when pairing bronze and hardened steel for the individual sliding elements. As Solid lubricant is particularly suitable for a combination of oil and graphite. The provision of, in particular, maintenance-free lubrication is not provided in the prior art, for example US 2,168,377, US 1,723,935 and US 4,993,295. Lubrication of the surfaces sliding into one another can only be accomplished there by dismantling the entire device. Maintenance-free lubrication proves to be advantageous due to the poor accessibility of the lubrication points and the otherwise long service life of the wiper device.

The guide element is preferably formed in one piece with the fastening piece or the guide element and fastening piece are designed as elements that can be joined together. A one-piece design is particularly suitable for higher forces, since in this case there is no need to fear an undesired tilting of the guide element and fastening piece into one another. The stability and compactness of the stripping device is increased. On the other hand, the formation of the guide element and the fastening piece is suitable as elements that can be joined together, in particular with lower forces. In this way, in particular, only one fastening with only one fastening means, in particular a screw, can advantageously be selected. The fastening piece can thus be made smaller and thus more space-saving.

At least one projecting area and / or projecting section, in particular a claw-shaped or clip-shaped section, is or is particularly preferably provided on the circumference or edge of the fastening piece for gripping around a fastening device of the cutting tool. Here, the fastening piece can be centered on the fastening device, in particular a fastening plate. Secure and centered attachment or locking of the stripping device to the cutting tool or its Fastening device is thereby also possible using only a single fastening means, in particular a screw. Compatibility of the fastening piece with a standardized fastening plate of a cutting tool proves to be very advantageous, since this means that there is no need to manufacture individual parts, as in the stripping devices of the prior art described above, and there is a precise fit on any existing fastening plate. A quick and easy exchange of a scraper is therefore also possible for inexperienced operating personnel.

The stripping device is particularly preferably used together with a wedge drive, since with such a not only particularly high forces can be transmitted, but this must also be done particularly precisely. The anti-rotation device is in the hundredth of a millimeter range, which cannot be achieved with the wiping devices of the prior art.

For a more detailed explanation of the invention, individual exemplary embodiments are described in more detail below with reference to the drawings. These show in:

Figure 1 is a schematic diagram of a built in a cutting tool

Hole punch with stripping device according to the invention during the stamping process of a sheet, FIG. 2 is a sectional view of a first embodiment of a stripping device according to the invention,

Figure 3 is a 90 ° rotated sectional view through the

Scraper device according to FIG. 2, FIG. 4 shows a top view of the scraper device according to FIG. 2, FIG. 5 shows a longitudinal section of a second embodiment of a scraper device according to the invention for use in the case of medium-level forces, FIG. 6 shows a top view of the embodiment according to FIG. 5,

FIG. 7 is a longitudinal sectional view rotated by 90 ° of FIG

Stripping device according to Figure 5, Figure 8 is a plan view of a further embodiment of a stripping device according to the invention with a rotated by 90 ° compared to the embodiment in Figure 6

Scraper element, FIG. 9 shows a longitudinal sectional view of a further embodiment of a scraper device according to the invention for strong occurring forces,

FIG. 10 shows a longitudinal sectional view of the stripping device according to FIG

9 and FIG. 11 a top view of the stripping device according to FIG. 9.

FIG. 1 shows a basic sketch of a cutting tool 1 in the area of the detail of a punch 2 with surrounding stripping device 3. The stripping device 3 is fastened to a fastening plate 5 of the punch via a fastening plate 4. The mounting plate 5 is in turn mounted on the cutting tool 1. The mounting plate 5 has a standardized shape. In Figure 1, the situation is shown in which the punch punch punched through a sheet 6 as a workpiece to be machined. The sheet lies against a front surface 7 of the stripping device 3 during the punching process. The hole punch dips into a counter punch 8 after the sheet has penetrated. The section punched out of the sheet falls through a through opening 9 provided in the counter-punch into a collecting container (not shown).

As can clearly be seen in FIG. 1, the stripping device has a front surface shape corresponding to the sheet metal shape. As a result, the sheet is supported during the punching process and is not deformed at the same time. The shape of the front surface of the stripping device can be carried out on site at the respective user. Depending on the forces occurring, the stripping device can be designed differently, as shown individually in the following figures. FIGS. 2 to 4 indicate an embodiment which is more suitable for lower forces, FIGS. 5 to 8 an embodiment which is suitable for stronger forces, and the embodiment according to FIGS. 9 to 11 a variant which is suitable for high forces Forces is suitable. The front surfaces of the stripping devices can be designed correspondingly differently.

FIG. 2 shows a longitudinal sectional view of a first embodiment of the stripping device 3. The stripping device 3 is fastened to the fastening plate 5 of the cutting tool via the fastening plate 4, as can be better seen in particular in FIG. 3. In this embodiment, this is done only by means of an indicated screw 10, better seen in FIG. The fastening plate 4 fastens a guide sleeve 11 of the stripping device. As can be seen from FIGS. 2 and 3, the fastening plate 4 protrudes inwards in its upper region and overlaps a section 12 of the guide sleeve inserted into the fastening plate, which protrudes below. As can be seen in particular from FIG. 4, the projecting section 12 is provided only along a partial area of the circumference of the guide sleeve. This is sufficient to hold the guide sleeve and to prevent it from tipping. In the area in which the screw 10 is inserted through the fastening plate, the guide sleeve is designed without a projecting part, as is also in the area offset by 90 °, which can be seen on the left in FIG. 4. This enables the guide sleeve to be displaced by 90 ° within the fastening plate. An elongated hole 14 provided in an upper end plate 13 of the guide sleeve, which can alternatively be a polygonal hole, can also be offset by 90 °, which is advantageous in certain applications proves that fewer different stripping devices have to be provided as a result.

The guide sleeve 11 is essentially cylindrical and in its upper region with that which is essentially perpendicular to the lateral surface of the. Guide sleeve extending end plate 13 with slot 14. A stripping element 15 is arranged within the guide sleeve and the elongated hole. The stripping element 15 is guided and slidable within the guide sleeve. This is made possible by providing a lubricant 16, in particular a solid lubricant. The stripping element has a straight section 17 and a projecting section 18. The lubricant 16 is provided in the area of the straight part 17. The cantilevered section 18 extends substantially up to the inner surface 19 of the guide sleeve and is slidably guided on this guide surface. As can be seen in particular from FIG. 3, the projecting section 18 is not provided over the entire circumference of the stripping element 15, but rather only along the long sides. The straight section therefore has a different wall thickness, as can be seen in FIGS. 2 and 3.

The elongated hole and the stripping element have an irregular cross section. This is characterized by three straight sides 141, 142, 143 and a curved side 144. Corner transitions 145, 146, each provided with radii, are formed between the two long straight sides 141, 142 and the short straight side 143. Due to this irregular and at least partially asymmetrical design of the cross sections, the correct orientation can be ensured when installing the stripping element, with quick and easy installation. In addition, comparatively large areas are advantageously provided on the stripping element for absorbing forces when generating an anti-rotation device. In order to create a damping and a resetting mechanism, a resilient element 21, for example in the form of a rubber spring, is provided adjoining the projecting section 18 on its underside 20. This surrounds, like the wiping element 15, the punch. In contrast to the stripping element, however, it is arranged concentrically with essentially the same wall thickness around the punch. On the other side of the resilient element, a retaining washer 22 is arranged, the outer surface 23 of which is essentially flush with the outer surface 24 of the fastening plate 4. This creates a defined counter surface for supporting the resilient element.

On the fastening plate 4, an area 50 protruding at the edge beyond the actual outer surface 24 and a further claw-shaped or clip-shaped section 51 are provided. This can best be seen in FIG. 4. The protruding area 50 and the protruding section 51 encompass the outer edge 52 of the fastening plate 5 of the cutting tool. As a result, centering of the fastening plate 4 and thus of the entire stripping device 3 and secure locking by means of only one screw 10 on the fastening plate 5 of the cutting tool is possible.

The wiping element 15 is guided in the area of the elongated hole 14 in the end plate 13 from the outside and along its through opening 25 on the punch to be inserted here from the inside. For this purpose, the seat on the punch is preferably designed as a snug fit.

The front surface of the stripping element 15 is chamfered or shaped in accordance with the workpiece shape. The passage opening 25 already provided in the stripping element for carrying out the punch is driven completely through the stripping element, as is already shown by the dash-dotted lines in FIGS Figures 2 and ^' 3 is indicated. In this embodiment, a bevel angle α of up to 5 ° is preferably selected. For larger bevel angles, one of the embodiments according to FIGS. 5 to 8 is preferably selected. In these, the bevel angle α is preferably up to 10 °. The other shape of the front surface of the stripping element 15 is preferably adapted to the shape of the workpiece to be machined, in particular a sheet of complex shape. This adaptation also makes it possible to avoid undesired markings on the surface of the punched workpiece caused by the stripping element. Such in particular circular markings occur regularly in the devices of the prior art and lead to a lower quality of the punched workpieces or to rejects. In contrast to the embodiment according to FIGS. 2 to 4, in the embodiments according to FIGS. 5 to 8 the fastening plate is formed in one piece with the guide sleeve. This guide sleeve 26 is also longer in the region of its straight part 27 than the guide sleeve 11 according to FIGS. 2 and 3. The fastening plate part 28 of the guide sleeve 26 has a greater material thickness than the fastening plate 4 according to FIGS. 2 and 3. In addition, 6 and 8, two fastening screws 10 and two dowel pins 53 are provided for fastening to the cutting tool or to the fastening plate of the punch. The thicker mounting plate part provides greater stability, which means that greater lateral and thrust forces can be compensated for.

In contrast to the embodiments according to FIGS. 2 to 4, the guide sleeve is of such a length that it can be applied directly to the cutting tool and thereby also covers the fastening plate 5 of the punch, in particular with a standardized shape. This can be seen in particular from FIGS. 5 and 7. The covering is only one-sided, as can be seen in FIG. 5, similar to the above area 50 according to FIGS. 2 to 4, which is why the jacket of the guide sleeve is not of uniform length. In the area of the mounting plate of the punch, the guide sleeve is shorter in order to end above it.

The difference between the embodiments according to FIGS. 5 to 7 and 8 is that although an elongated hole or polygonal hole is provided in both cases, it is arranged offset by 90 °. This possibility has already been mentioned for FIGS. 2 to 4. The rotation of the stripping element or guide sleeve by 90 ° is clear from FIGS. 6 and 8. The rest of the design of the stripping element and the guide sleeve as well as the resilient element and the retaining washer are essentially identical in both embodiments. In all of the illustrated embodiments, unwanted twisting is no longer possible after installation and fastening, since by providing the elongated hole 31 with three straight sides 311, 312, 313 and a curved side 314 and with corner transitions 315, 316 provided with radii or any other formed hole and the corresponding design of the stripping element an anti-rotation device is provided, which is in the hundredths of a millimeter range. The scraper element preferably consists of high-quality bronze. The guide sleeve is preferably made of steel. Because of this pairing of materials, a particularly high-quality guidance of the stripping element can be produced in the steel body of the guide sleeve, and a long durability or lifespan of the stripping device can be created. This is about five to ten times the previously known scrapers. The wearing part is only the resilient element. However, this lasts more than 1 million strokes and thus a multiple of the durability of the known stripping devices.

Through the projecting section 18 of the stripping element, which corresponds to the stripping element according to FIGS. 2 to 4 except for the dimensions In addition to the anti-rotation lock, a stroke limitation can also be generated. This is done in that it can be moved up to a maximum of just before the end plate 13 or 29. The provision of the anti-rotation device in the form of the elongated hole 14, 31 and the corresponding design of the stripping element can also absorb thrust forces in addition to the guiding function. Depending on the application, it is also possible to adapt to different shaft diameters of the punch by means of through-openings 25 or 30 of the wiping element or the through-opening 32 of the resilient element of different sizes. Larger lateral forces can also be absorbed by the longer guide length of the guide sleeve. The guidance takes place, as in FIGS. 2 to 4, with respect to the stripping element, again from the inside and outside, that is to say in the end plate 29 of the guide sleeve 26 and on the punch along the passage opening 32 of the stripping element 15. Despite the sometimes very different shape of the front surface of the stripping element, Moments acting on the stripping device can be optimally absorbed by the provision of the guide surface pairings and the device for securing against rotation.

FIGS. 9 to 11 show an embodiment which is suitable for particularly high shear forces or lateral forces. In this embodiment, guide bushes 33 are provided instead of guide sleeves, the guide bushes 33 being arranged within a stripping element 34. The guide bush 33 runs on the punch, not shown. For this purpose, it has an inner through opening 35. The stripping element 34 is of larger design than in FIGS. 2 to 8. It is trapezoidal in shape, with large through openings 39, in which fastening means for fastening the stripping device to the cutting tool are seated. This area of the stripping element is the fastening section, which instead of a separate fastening plate and a fastening piece as in FIG 5 to 8 is formed on the stripping element itself. In order to be able to better absorb side and thrust forces, attachment to the cutting tool via two shoulder screws 36 is provided. These sit in guide bushes 37, 38, which are inserted in paragraphs in the through holes 39. As can be seen from FIG. 11, the shoulder screws 36 are fastened directly in the cutting tool, surrounding the fastening plate 5 for the punch on both sides. This corresponds to the structure according to FIGS. 5 to 8. The guide length of the stripping element is increased again in comparison to the embodiments according to FIGS. 2 to 4 and 5 to 8, this being determined by the shape of the stripping element and the type of fastening via three guide bushings. The scraper element is guided from the outside and from the inside, as can be seen particularly in FIG. 9, on the punch and on the shoulder screws. This embodiment is secured against unwanted twisting by providing a special shape of the area of the stripping element surrounding the two shoulder screws 36 for gripping around the fastening plate 5 and by fastening it via the two shoulder screws on the cutting tool (see in particular FIG. 11).

In addition to the embodiments described above and shown in the figures, numerous further embodiments can be formed, in each of which a stripping element coming into contact with the workpiece and surrounding a cutting element, at least one guide device guiding the stripping element and an anti-rotation device are provided on the stripping element. A spring-elastic element, which is also provided, is arranged outside the workpiece contact area and is only used for damping and resetting the stripping device. Reference character list

1 cutting tool

2 punches

3 scraper

4 mounting plate

5 mounting plate

6 sheet

7 front surface

8 counter stamps

9 through opening

10 screw

11 guide sleeve

12 cantilevered piece

13. End plate

14 slot

15 Wipe down

16 lubricants

17th straight part piece

18 cantilevered piece

19 inner surface

20 bottom

21 resilient element

22 retaining washer

23 outer surface

24 outer surface

25 through opening

26 guide sleeve

27 straight section

28 mounting plate part 1

29 final splits

30 through opening Long hole

Through opening

guide bush

Wipe down

Through opening

Pass shoulder screw

guide bush

Through opening

Fastening part 1 protruding area part protruding part outer edge

Dowel pin long straight side long straight side short straight side curved side

corner transition

Corner transition long straight side long straight side short straight side curved side

corner transition

taper

Claims

Expectations

1. Scraper device (3) for use with a cutting tool (1) with a cutting element, in particular a punch (2), for machining a workpiece, in particular a bent sheet (6), at least one fastening piece (4, 28, 40) for fastening to the cutting tool, a spring-elastic element (21) arranged outside the workpiece contact area, a stripping element (15, 34) coming into contact with the workpiece and surrounding the cutting element (2) and at least one stripping element (15, 34) guiding guide element (11, 26, 33) are provided, characterized in that a device for securing against rotation is provided for essentially preventing the wiping element (15) from rotating.

2. Scraper device (3) according to claim 1, characterized in that the device for securing against rotation comprises a scraper element of uneven cross-section.

3. wiping device (3) according to claim 1 or 2, characterized in that the device for securing against rotation comprises an elongated hole (14) or polygonal hole in the guide element.

4. Scraper device (3) according to any one of the preceding claims, characterized in that the device for securing against rotation an at least in one orientation asymmetrically formed pairing of stripping element and hole or opening in the guide element to ensure has a clearly oriented installation of the stripping element, in particular an elongated hole with three straight (141, 142, 143, 311, 312, 313) and a curved side (144, 314) and a correspondingly designed one. Scraper element (15).

5. Scraper device (3) according to one of the preceding claims, characterized in that at least one guide sleeve (11, 26) is arranged as a guide element outside the scraper element (15), at least partially surrounding it and / or that at least one guide bush (33) as a guide element within the stripping element (34), this is arranged in a leading manner.

6. Scraper device (3) according to one of the preceding claims, characterized in that at least one guide surface (19) between the scraper element (15) and guide element (11, 26) is provided, the length of which depends on the forces acting on the scraper device, in particular thrust - and lateral forces, can be selected to ensure tilt-free guidance. •

7. Scraper device (3) according to claim 6, characterized in that the scraper element (15) has a substantially straight section (17) and a projecting section (18), wherein guide surfaces on the straight and the projecting section (17, 18th ) of the stripping element (15) are provided.

8. Scraper device (3) according to one of the preceding claims, characterized in that the stripping element (15, 34) has at least one guide surface on its inside facing an inserted cutting element (2), in particular its shaft, and / or the stripping element (15, 34) and the spring-elastic element (21) have the cutting element ( 2) are aligned in such a way that they can be loaded with essentially no torque.

9. Scraper device (3) according to one of the preceding claims, characterized in that a lubricant (16), in particular a solid lubricant, is provided at least in a partial region of the straight partial piece (17).

10. Scraper device (3) according to one of the preceding claims, characterized in that the guide element (26) is formed in one piece with the fastening piece (28) or guide element (11) and fastening piece (4) are designed as elements which can be joined together.

11. Scraper device (3) according to one of the preceding claims, characterized in that the resilient element (21) between the scraper element (15) or guide element (33) and cutting tool (1) and / or within the guide element (11, 26) is arranged ,

12. Scraper device (3) according to any one of the preceding claims, characterized in that - at least one projecting area (50) and / or projecting section (51), in particular a claw-shaped or clip-shaped part, on the circumference of the fastening piece (4) for Gripping around a fastening device (5) of the cutting tool (1), in particular standardized mounting plate, is or are provided.

13. Wiping device (3) according to one of the preceding claims, characterized in that the wiping element (15, 34) can be provided or provided with a shape corresponding to the workpiece and in particular consists of bronze or another workable material which can be adapted to the shape of the workpiece surface.

14. Scraper device (3) according to one of the preceding claims, characterized in that the resilient element (21) is a rubber spring or consists of another resilient, restoring or resilient material.